# Improved Maha C9000…



## SilverFox

I was reading the information on the C9000 (Wizard 1) charger over at Thomas Distributing. There were several things listed that seemed different to me. One was a 15 cycle capability, another was the Break In mode was referred to as going through 4 cycles and ending with a medium charge.

I believe these differences came from pre-production notes, but then I had the wild idea that perhaps Maha has slipped some changes in under our noses.

I prefer the Wizard 1 over the BC-900, so I recently acquired a second C9000 charger.

I have noticed some differences…

I was using the Refresh/Analyze mode. 

My original charger would charge first, rest for an hour, discharge, rest, then charge back up. During the rest period between charging and discharging I would see the voltage gradually settle down from the peak charge voltage.

My newer charger does this differently. It still follows the same sequence, but the rest time between charging and discharging is now two hours, and the voltage holds steady. It is as if there is now a top off charge being applied during the rest period.

The next thing I noticed was that while charging a 9000 mAh D cell, external to the unit, it stopped charging at 4000 mAh. We have seen AA cells that have missed their charge termination signal go for longer than that.

Finally, I took my Tenergy cells that missed the end of charge termination on both the C9000 and the BC-900 when charging at 500 mA, discharged them, then charged them in this latest C9000 to see what would happen. All the cells terminated properly.

Does anyone else have a recent C9000? Have you noticed any other changes in it?

My original one was purchased during the pre-sale. This last one came last week.

Tom


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## dekelsey61

Hi Tom,
Where did you get your latest charger at? Could "The Cat Out Of The Bag" be true? Have you called Maha? I do believe this could be the best charger out there with the improvements you mentioned! Maybe Maha listened to you and some other people. Enjoy your NEW C9000 charger. I should get mine Friday. Thank you for the updates.
Dan


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## viorel00

is there any other difference, like a revision on the bottom of the case, or a firmware number flashing when you plug it in (a-la BC900)


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## coppertrail

Mine should be here on Wed. Thanks for the rundown on the changes. I too would like to know if the code on the bottom of the newer chargers are different from the first run models.


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## SilverFox

Hello Dan,

Thomas Distributing is the only place that I am aware of that is selling the C9000, but I didn't look beyond there. I am assuming that this is what they now have.

I have been feeding information to William at Maha, and had a feeling "something was in the works," but I was expecting it to take a while for any changes.

Tom


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## SilverFox

Hello Viorel,

The only difference that I can see is in the way the display is mounted. My original unit seems to have a very thin dark line along the left side of the display. The new unit has the display centered in a way that eliminates that line.

There is no version number or other changes in the start up information.

Tom


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## SilverFox

Hello Chris,

It will be interesting to see what you get. Do you have an older model to compare with?

Tom


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## coppertrail

Tom - I do currently have a pre-order C9000. Have you noticed any differences in cell temperatures during charge?


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## dekelsey61

Tom,
I have a older model to compare to. I will get mine on Friday. I will compare.
Dan


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## SilverFox

Hello Chris,

I have only had heating problems with one set of cells and I sent those cells off to Maha for evaluation. 

I have my "charger evaluation" test cells charging right now and should be able to see if they changed the charge termination...

Tom


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## webfors

Interesting... please keep us posted. I received mine about 2 weeks ago so I'm not sure if it would be a new one or old.


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## SilverFox

Very interesting...

My test cell results came in at roughly the same results as what I got from the Maha 808. Cells were charged at the default rate and the cell temperature ended up at 105 F. Cells were pulled as soon as "Done" appeared and were not topped off.

It looks like there has been a change in the charging algorithm as well.

Tom


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## Nebula

Tom - Thank you for the exceptional investigative work that you do. I plan to call Thomas tomorrow to discuss returning my pre-order charger for a newer version. Kirk


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## digitor

*Re: Improved Maha C9000…*

I notice that the info on the Australian distributor's website (http://servaas.com.au/maha-powerex-c9000-wizardone-battery-charger-analyzer-p-52.html) has also changed recently, to reflect the changes that Tom is talking about. My C9000 is from the first batch to arrive in Oz, which was pre-sold out. 

The second shipment has arrived now, and seems to be the new spec. There's no mention on the Thomas or Maha site, or anywhere else of any changes in the spec., such as "New Improved Version" or anything like that - I feel like a mushroom!*

Cheers

* (Kept in the dark, and fed on sh1t)


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## SilverFox

Hello Kirk,

You may be better off contacting Maha...

Tom


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## SilverFox

Hello Digitor,

The information you referred to was what got me going about checking things out. My unit does not support 15 cycles, so their information either a pre-production idea, or a preview of more changes. Since it is the same shots that Thomas Distributing has had for awhile, I believe it is more of a pre-production wish list. They got most of it, but we seem to be ending up with 12 cycles instead of 15.

If the mushrooms and you grow rapidly, does that mean you are in really good sh**? 

Tom


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## coppertrail

SilverFox said:


> Hello Kirk,
> 
> You may be better off contacting Maha...
> 
> Tom


Agreed, Maha is sending me a "2nd Ed." replacement charger with a pre-paid return label.


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## SilverFox

As much as it pains me to do so, I decided to try charging at a slower charge rate to see what this improved C9000 would do.

MarkCM gave me some Moden 850 mAh AAA cells. These cells have been sitting around for an extended period of time and were at 0.6 volts. This means that they have been in storage for a long time. If I had purchased cells that were in this condition, I would have returned them.

The C9000 seems to have “issues” with AAA cells, especially at lower charging rates. I decided to charge these cells at 400 mA on the improved C9000.

The charger did have some difficulty terminating the charge, but it did finally terminate all 4 cells. Maximum cell temperature was 105 F. Charge input was as follows:

Slot 1 - 937 mAh, 158 minutes
Slot 2 - 911 mAh, 154 minutes
Slot 3 - 1233 mAh, 207 minutes
Slot 4 - 870 mAh, 145 minutes

As you can see, the cell in slot 3 gave this charger a run for its money, but it still terminated. I would normally do a Break In on cells in this condition before even trying to do a normal charge. I am impressed.

Now that these cells have been charged, I discharged them and charged them on my original C9000. Once again I used a 400 mA charge rate. None of the 4 cells terminated. This time the cell temperature only got to 97 F. The voltage got up to 1.47 volts and stayed there. I manually terminated the charge after 2500 mAh was put into the cells.

I think this improved C9000 has really been “improved.”

A final test to check things out. These AAA cells have a couple of cycles on them, including a missed termination. I discharged them, then charged them on the improved charger, this time using a 200 mA charge rate. 

How slow can you go and still terminate?

Surprise, all of the cells terminated. Here is what I got.

Slot 1 - 694 mAh, 233 min
Slot 2 - 697 mAh, 234 min
Slot 3 - 912 mAh, 306 min
Slot 4 - 650 mAh, 219 min

Please understand that I don’t recommend charging at this slow a rate unattended. I would expect missed terminations, but in this case, all the cells terminated.

Tom


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## alins

A friend of mine contacted Maha a few weeks ago. The reply from Maha
follows and confirms the new improved C9000:

--
Dear ------:

Many thanks. The next shipment of the C9000 chargers will arrive here
around Feb 18~20. 

We always collect the suggestions from the customers and then improve our
products to make sure the high end products we provide. As to the
concerns and suggestions from the customers, they are all improved for the
next shipment. Actually the customers have the higher expectation of
this charger than we imagine. To serve the customers we made more effort
to improve it though the cost will be higher. Please keep contacting me
when the shipment arrives here.

Best regards & have a great weekend.

James
Maha Energy Corp.


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## EngrPaul

What if you unplug it and plug it back in, with cells in the bay... does it start charging them?


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## bmoorhouse

Excellent!!

When I returned my C9000 to TD earlier this month, they told me that if I reordered the C9000 after March first I would be happy. I guess it looks like the updated model they were referring to is being sent out a little earlier than they anticipated.

I will definitely be ordering this newer model, but a few questions for those that already have it . . . 

1. Why did it stop at 4000 Mah? Is that a new artificial limit? Can the user adjust that or will the updated model not be able to charge C and D cells externally anymore?
2. Did Maha change anything that would allow you set all four bays simultaneously?
3. Did Maha change anything regarding the way the data is displayed? For example can you skip from cell to cell while displaying voltage without having to wait for the device to scroll through all other data fields first?

Either way, the fact that this newer unit terminates better and seems to stay cooler is enough for me. Thanks for posting and I will continue to follow this thread to see what other changes you guys find.


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## wptski

coppertrail said:


> Agreed, Maha is sending me a "2nd Ed." replacement charger with a pre-paid return label.


Interesting! They offered me 4-8 weeks turnaround time for a upgrade if I requested a RMA for my two C9000's!


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## Nebula

wptski said:


> Interesting! They offered me 4-8 weeks turnaround time for a upgrade if I requested a RMA for my two C9000's!


 
I had the very same experience.


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## wptski

Nebula said:


> I had the very same experience.


I wish that they get their official policy straight!


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## SilverFox

Hello EngrPaul,

After charging some AA cells, I unplugged the unit and plugged it back in to simulate a power failure. This is what I observed:

Slot 1 - 14 mAh, 1 min
Slot 2 - 26 mAh, 2 min
Slot 3 - 20 mAh, 1 min
Slot 4 - 20 mAh, 1 min

Tom


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## SilverFox

Hello Bmoorehouse,

It appears that we have lost the capability to externally charge C and D cells because the time limit has been reduced from 20000 mAh down to 4000 mAh. However, you can still select 20000 mAh as the capacity of a cell in the Break In mode. This means that you should be able to do a forming charge on large capacity cells, but when charging them, you would have to restart the charge a few times.

You still have to program each bay, but it seems that the delay time has been extended. With the original charger, when I inserted 4 cells I was often unable to get through the programing for each cell before it started charging at the default rate. With the improved charger, I can insert and program all 4 channels without problems.

There does not appear to be any difference with the way the data is displayed.

Tom


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## oldvultureface

For me, Maha was too late in improving their charger. I stumbled on this site (CPF) several weeks ago looking for information on battery chargers and low self-discharge batteries to feed my digital cameras. After reading all the flap about the C9000 I settled on a BC-900 and have been very satisfied.

By the way, thanks for all the useful info posted on this site!


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## patycake57

I wanted to thank everyone who has been working with this charger and with MAHA to make it better. I've gone ahead and ordered one.


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## coppertrail

I agree, there are numerous members who's contributions to the MH-C9000 threads no doubt led to some of the changes Maha made with this charger. Maha should send you a check  

So Tom, Bill, and numerous others, thanks again. Your efforts and time have resulted in a better charger!


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## EngrPaul

OK, so it proceeded to charge them (1000 mA?), but evidently it was only topping them off.





SilverFox said:


> Hello EngrPaul,
> 
> After charging some AA cells, I unplugged the unit and plugged it back in to simulate a power failure. This is what I observed:
> 
> Slot 1 - 14 mAh, 1 min
> Slot 2 - 26 mAh, 2 min
> Slot 3 - 20 mAh, 1 min
> Slot 4 - 20 mAh, 1 min
> 
> Tom


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## dekelsey61

Thank you to all the people like Tom+Bill and many others who talked to Maha and made this charger even better. Thanks so much again.
Dan


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## webfors

since I can only choose up to 12 cycles, it appears I have the old version. I am going to contact maha Monday and get the process rolling for the new version.

Thanks to all for the info!!


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## verge

SilverFox said:


> another was the Break In mode was referred to as going through 4 cycles and ending with a medium charge.





> I was using the Refresh/Analyze mode.
> 
> My original charger would charge first, rest for an hour, discharge, rest, then charge back up. During the rest period between charging and discharging I would see the voltage gradually settle down from the peak charge voltage.
> 
> My newer charger does this differently. It still follows the same sequence, but the rest time between charging and discharging is now two hours, and the voltage holds steady. It is as if there is now a top off charge being applied during the rest period.



How/why are these changes for the betterment of conditioning and charging of batteries?


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## SilverFox

Hello Webfors,

There is NO 15 cycle version. All have 12 cycles.

Tom


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## coppertrail

It appears as though the newer models have a G in the product code on the bottom of the charger.


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## dekelsey61

Newer model-the Code is 0G0B01.


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## SilverFox

Hello Verge,

The first comment you refer to, along with the mention of the original idea of having up to 15 cycles, were just differences that I have noticed while searching for information on this charger. The product evolves along the process from design to production. Changes are made and features are added or dropped. 

Marketing is eager to get the hype out so we have a "best guess" from the design team. All of this can take place before there is an actual product. Hopefully there are working prototypes, but as things get closer to actual production, changes continue.

It would be nice if a manufacturer could (or would) provide updates, but there are times when reverse engineering a change could give an advantage to a competitor and hurt the manufacturer. 

So, we end up with some discrepancy in the description of the product.

The second statement you quoted shows the trade off required to get accurate information. 

The original charge algorithm charged cells to roughly 96% of their capacity at the default charge rate. The improved algorithm ends up with cells that are roughly 3% less than this. 

In the Refresh/Analyze mode we are trying to get a number that tells us what the capacity of our cells are. If everything stayed the same, our cells would register 3% less capacity on the improved charger. Realizing this, Maha changed the mode to include the top off charge before the discharge. This is an attempt to bring the cell up to a full charge state so we get a better idea of what the capacity of the cell is.

Now, for your question as to which is better, there are trade offs both ways.

"Fuller" charging can result in higher cell temperatures with some cells, and, sometimes, missed terminations.

"Less fuller" charging takes more time, and, technically, does not incorporate a rest period with no activity.

Tom


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## BentHeadTX

Thanks for the information concerning the improved C9000, my BC900 can now take a much needed rest.


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## sharker

Has the product code been verified? So my charger delivered 2 days ago (0FAB02) is already obsolete?!


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## coppertrail

It appears as though you have the first run model. Where did you purchase the charger?


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## verge

SilverFox... thanks for the explanation. 

sharker, 0FAB02 is also the product code at the back of my MH-C9000. It came from the second shipment of C9000 and delivered to me last January 12th.


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## J_Oei

So, who do we talk to? Maha? Thomas Distributing?
Looking through the thread, it looks like Maha has a 4-8 week turnaround? And it looks like TD is shipping new stock after March 1st? So, do we send it back to TD?

My model # is 0FAB01


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## LuxLuthor

Yeah, I also got one of these after following the other thread, and mine is also *#OFAB02* from Thomas Distrib in early Jan. I am going to ask them about getting an upgrade...but with SilverFox's last post, and all the other threads I have wandered into, it is not clear to me that he is saying the later version is clearly better. 

I'm not even sure from reading this FAQ 9 page thread, and this 14 page thread, and this 20 page thread (LOL !!!) if I should have bought this charger. I have spent about 4 hours reading about 1/2 of what has been posted so far....LOL!

Also, just a simple question on this model....for batteries like the Eneloop 2000 mAh, or PowerEx 2300 or 2500 mAh, why don't more of you guys run the "Charge" mode on 2,000 mA charge rate, since it is <1C for these cells?


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## coppertrail

*Contact Thomas Distributing*

I just got off the phone with Thomas Distributing. If you purchased your C9000 through them, and have the original model, contact them and they will assist you in getting your C9000 replaced with the newer model. That's customer service at its finest! :thumbsup:


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## jusko

Hi, Tom,
Have you tried whether those cells that show "HIGH" in the previous model also show the same in the improved model ?

thanks

jusko


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## Dan C

*Re: Contact Thomas Distributing*



coppertrail said:


> I just got off the phone with Thomas Distributing. If you purchased your C9000 through them, and have the original model, contact them and they will assist you in getting your C9000 replaced with the newer model. That's customer service at its finest! :thumbsup:



Ya' did better than me, I just got this e-mail from them:

"Dan,
I am sorry that you are not satisfied with your MH-C9000 battery charger, 
but because there is no known defect with this particular charging unit, we 
ask that you contact Maha at 800-376-9992 for your replacement. Let them 
know that you purchased this charger from Thomas Distributing and you would 
like a replacement. If you are not completely satisfied with the service 
that is given by Maha, contact us immediately and we will take care of the 
situation. Thanks in advance.

If we may be of further service, please let us know."

Kayla

Thomas Distributing
128 East Wood Street
Paris IL, 61944

Dan C


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## SilverFox

Hello Jusko,

Yes.

Tom


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## wptski

Dan C:

I think that "maybe" MAHA has put a stop to them replacing the chargers outright through them!


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## webfors

I just got off the phone with maha support. They informed me the process is a 4-8 week turn around on the c9000, while they send your charger to taiwan for modifications, and ship it back to you. Now this is where a nice PC hookup for flashing on these things would of come in handy and save everyone a lot of hassle.. shipping it across the world for software update.. but then again you do get your same charger back.. is that a + or a - ?


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## coppertrail

From Dan C's email response from TD:

"If you are not completely satisfied with the service 
that is given by Maha, contact us immediately and we will take care of the 
situation."


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## Dan C

coppertrail said:


> From Dan C's email response from TD:
> 
> "If you are not completely satisfied with the service
> that is given by Maha, contact us immediately and we will take care of the
> situation."



Yeah, I got that part coppertrail, thanks for enlarging it. I'm not bitching buddy, just adding their response so others might know what to expect.

Dan C


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## coppertrail

Hi Dan - This was in no way intended towards you nor anyone in particular, I know you're not bitching. Webfors posted his response from Maha and my point was to to call TD if you're not satisfied with the service you receive from Maha.


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## webfors

I think I'll wait it out another couple of months.. maybe there will be a 3rd, or 4th revision !

TD has always been great with respect to replacing products I purchased there, so I'll let them catch up with y'all's and call them in April


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## LuxLuthor

What reasons have you guys given TD/Maha for the replacement?


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## summerwind

LuxLuthor said:


> What reasons have you guys given TD/Maha for the replacement?


 

mine are just little things like it melt the wrappers off 2 cells..............has missed termination a couple times, and oh yes, i have to find the perfect angle to see all the digits now.................no biggee i guess


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## LuxLuthor

summerwind said:


> mine are just little things like it melt the wrappers off 2 cells..............has missed termination a couple times, and oh yes, i have to find the perfect angle to see all the digits now.................no biggee i guess



LOL! Yeah....just those little things...OMG!

Also, if Tom is seeing the same problem with his newer version still not working with those "HIGH" status cells, I'm asking again....is this newer version really making that much difference....or should we look at this charger as a fancy "Discharge-Capacity Detector" only? 

I'm questioning if the mailing expense to MAHA is worth bothering with if the upgraded version is not that much better.


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## LuxLuthor

I'm still not sure if the general consensus is that this charger is still not safe to use, even if you wait for the 6-8 weeks slow boat to Taiwan for later version. I now have experienced the lack of termination on two of my PowerEx 2200 cells....taking 5000 & 6000 mAh respectively before I aborted the charging fiasco.

After having bought the MH-C401FS (which was ok, but too unsophistocated), & then the MH-C777 Plus II (which also turned out to be a major battery cooker), I got pissed off over all this feeling of being ripped off again by Thomas Dist. and ordered the *HP-EOS1210 Hyperion Lipo/Nimh/Nicad Charger & PK12PS Pyramid 10amp PS* from CheapBatteryPacks.com

I know this is more expensive than the Triton, but I got it on the advice of Mad MaxaBeam who has been one of the most helpful and responsive members I have dealt with on CPF's. I may still return this latest MAHA battery cooker for an upgraded version...but enough already for me.


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## SilverFox

Hello LuxLuthor,

Let's make sure we are on the same page here...

Cells that have degraded to the point that they have high internal resistance are rejected by chargers that check for that. I view this as a feature of the C9000, not a problem.

If you have a bunch of cells that are showing "High," you need to recycle them and replace them.

My "crap" cells that show "High" are not in service, but are only used to check if the charger does a check for high internal resistance.

Good cells will stay cool during charging and hold a higher voltage under load. Keep in mind that a brand new cell can be "crap," and an old cell can be "good." This is not much of an issue when charging at low charge rates, but becomes one at higher charge rates. The same goes for using the cells. If you are only drawing 250 mA from them, they will probably be OK, however they will underperform at higher current draws.

If Maha changed the C9000 so it started accepting "crap" cells, I would send mine back for a refund.

If your C9000 is working well and you have had no problems with missed terminations, or hot cells, there is no reason to change to the improved C9000.

Tom


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## LuxLuthor

OK, I did misinterpret your noting that a later revision model also reported the "HIGH" status as bad, but I now see that you consider that a good feature. I guess I was reacting to the many posts in those other threads where people were seeing this charger as being more capable of rejuvenating old cells that were left sitting. It sounds like it is not capable, and your recommendation in the HIGH cases is to always toss them. I understand your conservative reasoning, and it sort of makes sense from a relative cost of a battery vs. item powered.

Tom, I GREATLY respect you and the hundreds of your posts have taught me a lot. I also just edited my above post while you were posting to say that I now just had two PowerEx 2200 mAh (of a batch of four that were bought at the same time, and used in my MP3 player) that did not terminate, after having used the discharge mode on all 4 of them. The other two did terminate. 

The discharge reported the capacities as between 1450 - 1640 mAh. They were rested for about 6 hours, and then all done in CHARGE mode at 1.5A...and I did not do a forming charge on them. They had previously been charged in a typical consumer "noobish" haphazard manner by either the 9V 600mA MP3 charger (Archos model 50277), and about every two months in the MH-C401FS, so I clearly have not yet graduated from the Battery University...but I'm enrolled at least.

I didn't have a reliable way of testing the temp, but those in slots 2&3 were much hotter to the touch than slots 1&4. Those in slots 2&3 did not terminate, and had 5,000+ & 6,000+ mAh before I aborted after reading all the posts here.


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## SilverFox

Hello LexLuthor,

It sounds like the improved C9000 would be good for you. You should not see a missed termination with it.

Tom


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## tacoal

it's good news.

It seems Maha listened the complaint from the users, better than La Crosse.


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## yaesumofo

I have the LaCrosse charger and am pretty happy with it.
I also have a couple of MaHA "professional" chargers maha 801 and 808.
Maybe I am just not that fussy but these all seem to work pretty well for me. Maybe I need to pay more attention but I charge a lot of batteries, I do it in the field when working I do a bunch of 9V charging which I have moved to Lithium technology, I have completely switched over to rechargeable vs Lithium primaries (9V) and alkaline cells.
I do a lot of charging. In the grand scheme of things all of the chargers I have work pretty well. If I put a cell on for charge and it is not seen by the Maha charger, I put it on the LaCrosse and refresh, if not seen by the LaCrosse it goes into the DEAD Battery bag(which goes to the hazardous materials collection point).
I occasionally do a refresh. What I know for sure is that batteries wear out, there is not anything that I have been able to figure out that avoids this. It happens. 
I really like the Break in mode available on the Maha c9000. This sounds like a really good idea and the one feature which attracts me the most to the c9000. My charging station is pretty full of chargers, I figured that the 808 would solve that, It is too big to solve this problem.
Anyway like flashlights, holsters and so many things related to the hobby I suppose I will just have to buy the c9000 and ad it to my collection of chargers. Maybe a clear winner will become obvious and I will be able to make some room in my charging station.
Yaesumofo


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## jusko

If the improved version terminates properly, why MAHA reduced the maximum charging capacity ? 

Regards
jusko


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## TorchBoy

A) Just in case.
B) That's what does the terminating now.  :devil:

Either way,


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## webfors

TD is awesome. Thought I would call them up just to see what they could do about the charger, and they informed me that they would have a new unit sent out to me directly from Maha to replace the current model. Now that is customer service at it's best 

Looking forward to playing with the new improved one.

If they really did change the charging algorithm, similar to the 808M, then I would be very pleased. My 808M is the charger that gives me the most peace of mind.


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## LuxLuthor

webfors said:


> TD is awesome. Thought I would call them up just to see what they could do about the charger, and they informed me that they would have a new unit sent out to me directly from Maha to replace the current model. Now that is customer service at it's best
> 
> Looking forward to playing with the new improved one.
> 
> If they really did change the charging algorithm, similar to the 808M, then I would be very pleased. My 808M is the charger that gives me the most peace of mind.



Yes I have to agree that Thomas Distributing just did great for me. I just called them at 10:00am EST and gave them my name and reported the failure to terminate with two 2200 mAh PowerEx cells. 

She looked up my name, verified that I received it in mid January, and volunteered having the new model shipped immediately to me by MAHA, with a return pre-paid label to return this OFAB02 model back to them. None of that 8 week slow boat to Taiwan story. 

I was actually prepared to threaten opening a credit card case requesting a refund if I had to wait 8 weeks over what I believe was a defective unit. This level of customer service just went a long way in promoting TD & MAHA in my book. They handled it perfectly.


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## coppertrail

Very good, this is awesome news!


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## wptski

Well, we shall see as I'll be calling TD for the third time later today. I tell them that it missed termination and overheats cells. They say that it's not a "defect" but a "oversight" on MAHA's part and they didn't seem to care that I was unhappy. I got a response from a email I sent yesterday saying that they didn't want a unhappy customes, so we'll find out later.


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## LuxLuthor

Well there may have been some contact made after your phone call(s) that prompted this easy and great customer service response today. I imagine there are those from Maha and/or Thomas that are lurking on these topics regularly, and as smart businessmen, realize that a lot of people will read these posts. This forum comes right up on a general Google search for problems with this charger.

So it may be directly a result of your calls and posts that they are "greasing the skids" on customers being able to return their latest battery charger whose early models did not terminate a number of cells. I also think they realize this could be a fire/product hazard issue, and it is smart to nip it in the bud like they are doing.

I certainly hope the young lady who took care of me is not getting in any trouble for providing the great customer service she did, and hope it is rather a change in TD policy on this charger model upgrade.


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## coppertrail

Thomas-Distribuiting has a member account on this forum; they're aware that this charger has been/is being discussed


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## tacoal

jusko said:


> If the improved version terminates properly, why MAHA reduced the maximum charging capacity ?
> 
> Regards
> jusko


 
By this, you know there is no improvement on how to terminate properly, just the safeguard acts.

It seems Maha has a silent recall on C9000


----------



## LuxLuthor

I'm wondering what would be the best way to get a better mAh rating on the two PowerEx 2200 mAh AA's that did terminate correctly. I have run a discharge (1650/1660 mAh capacity reported on them), then refresh/analyze cycle with 1.5A/900mA (charge/discharge) rates, but still only getting 1688 & 1705 mAh rating. 

Now that these are done with the refresh/analyze cycle, *what would be the best way to try and get closer to their 2200 mAh rating*? These 2200's are about a year old, and have not been properly cared for as I now know from reading the Battery University and so many of these posts on this charger. Thanks


----------



## wptski

LuxLuthor:

If you cycle them several times and they don't increase, that's it!  Maybe if you had a Cadence charger as it has some fancy routines to recover low capacity cells.


----------



## meeshu

wptski said:


> . . Maybe if you had a Cadence charger as it has some fancy routines to recover low capacity cells.



Out of curiosity, where and what is this "Cadence" charger? I can't seem to find any information on it!?


----------



## SilverFox

Hello Meeshu,

Try www.cadex.com

Tom


----------



## wptski

Well, I was close! I got four letters correct!! :lolsign:


----------



## meeshu

Thanks Tom!  

And I thought *I* was the one who needed more sleep!!  :lolsign:


----------



## webfors

Wow, the replacement charger arrived today! I called TD yesterday and I live in Canada! That's really impressive.

And yes, it's a brand new c9000 with the new model # 0G0B01.

That's great service from TD and Maha. I'm very pleased and satisfied with how this all went down.

Now, I'm off to plug the new charger in and put it to never-ending work


----------



## sylvainp

Wow this forum is great !

I have a Maha 808M and the bought the new C9000 (january 6) with model #0FAB01 on the back sticker.

I found my battery to come pretty hot at 1000 mah charge rate for my 2500 & 2700 battery. If I compare it to my 808M the heat generate with the c9000 is alot hotter than the 808M.

On slower charge it seems to not stop charging at the top of charge and the charge rated Mah seem to be on the high value too !

I write to Maha yesterday and this morning I found this forum and glad I did too !

Here what Maha respond from my email:
---------------------------------------
Hello,

Thank you for contacting Maha. There are no new revised models but it does
sound like your charger is defective. Since you are in Canada, I will have
a replacement shipped out first. Once you receive it, please send the unit
you have back to us for evaluation. All I need is your adress and phone
number.

Best Regards,
----------------------------------------

Is Maha trying to hide this new revised model to prevent to make a recall for the first preorder model ?

Just hope they will send me the latest model number as I request it in my responding email to them today.


----------



## coppertrail

The response from Maha is not correct, there is a revised code (hence an updated model). You are the first person I've heard of who has contacted Maha directly and the result was having a replacement charger shipped. :thumbsup:


----------



## sylvainp

Wow their fast ! As I wrote in the forum I received a new email from Maha

Here it is:
-------------------------------------------------
Hi Sylvain,

I am aware of this ongoing talk, but I can assure you that the numbers on
the back of the chargers have nothing to do with revisions. Unfortunately I
don't know what they mean or why they are different. I have a brand new
charger here that we just received, and it has the 0FAB01 label on it.

Anyways, if you feel more comfortable receiving one with a 0GB01 label, I
will pick it out of our inventory myself.

After you receive the new charger, please mail the old one back to us so we
can evaluate it to:

Maha Energy Corp.
Attn: 
1647 Yeager Ave.
La Verne, CA 91750

Best Regards,
---------------------------------------------

What you guys think about this respond ?

All I can say that Maha offers great customer service and pretty fast too !

But from the response i have from them is not exactly corresponding to what I read here in the forum.

One thing I know is that when I make a Refresh & analyse it will rest for an hour and the new revised model has a 2 hours rest so something has been change.


----------



## SilverFox

Hello Sylvainp,

Welcome to CPF.

I am not sure of all of the terminology, but there is no revised C9000. Maha improved the end of charge signal recognition, but it is not considered a "revision."

Let us know what you observe when you get your "improved" unit.

Tom


----------



## coppertrail

Call it what you wish, but they "improved" (thus changed) something. I consider this a "revised" model, terminology aside.

Just out of curiosity, I'd like to hear from anyone who receives a replacement that has the same code on the bottom as their original.


----------



## wptski

Tom:

What's the diff? A play on words?? Improvments, changes, revisions, upgrade, etc. Improvment 1.0.1??


----------



## LuxLuthor

Yeah, something is not making sense with your last comment, Tom. I honestly have never heard of a company who says they will pre-ship a "latest version" and trust the consumer to return ship with pre-paid mailer the "older version" which does not terminate, if the versions are identical. I thought you said earlier that the later version has a maximum mAh charging amount termination limit??? Maybe you are now talking about some other supposed new version beyond my OFAB02 ? I also cannot believe that these varying numbers on the bottom are meaningless. Manufacturers use them to track date, location, version, etc. that are made over time.


----------



## webfors

The new charger is definitely improved over the old. Looks like they solved the heat issue when charging at higher rates (> 1.5amps) and it successfully terminated on all 4 powerex 2700mah batteries when charged at 200ma. So if you don't like any heat at all, you can always charge at the lower rates (as long as you realize that you are increasing the chances of a missed termination, which applies to *any* charger when charging < .33C). 1 amp barely generates any real heat and is close to the .5c recommendation for most batteries, so the default charge rate of 1000mah should be perfect for most people.

It's safe to say the new version has been improved with regards to heat and missed terminations and I'm very happy about that


----------



## SilverFox

Hello Bill,

Looking into my dictionary, I find...

Improvement: A change or addition that improves.

Revision: A revised or new version.

Revise: To prepare a newly edited version; to reconsider, change or modify.

It almost sounds like a change in software could be considered an improvement, but if hardware components were changed it would be a revision...

Regardless of the term, the original charger worked well with a very high percentage of the cells charged within normal charging rates, but the improved charger seems to work even outside of normal charging rates, and with cells that are "less than healthy."

Tom


----------



## LuxLuthor

SilverFox said:


> Regardless of the term, the original charger worked well with a very high percentage of the cells charged within normal charging rates, but the improved charger seems to work even outside of normal charging rates, and with cells that are "less than healthy."
> 
> Tom



Tom, while that may very well be true...I think everyone's legitimate point is that if this charger was not terminating with even 5% of working cells, not to mention the other images of the increased heat actually splitting the plastic on cells, there is something fundamentally wrong. This improved revision goes beyond classifying it as merely improved, as there is clearly a significant product defect that is being addressed. 

Your asserting that the prior version was still "working well with a high percentage...charged with normal rates" is not a useful statement. I charged my PowerEx 2200's that were less than a year old at 1.5A rates, and two failed to terminate after 5,000+ & 6,000 mA's pumped into them. While 10 other various battery types did charge & terminate properly, the two failures is a totally unacceptable performance rate.

There had to have been at least a revision of the software, which in every other industry is called a "revision." Even if some sensing component (or a setting of some components) was made to solve these issues, it clearly constitutes a product revision. The same term was used with all of the revisions of the C900. I don't consider the semantics of the improvement terminology label as relevant. The hardware/software changes have been made, and free advance shipping with pre-paid return shipping are done when a company realizes something is fundamentally wrong. The key word is "fundamentally," as these replacement costs are not trivial.

You saw the same thing with all of the Sony Li-Ion computer battery recalls when fires developed in multiple instances. Yes, while the problem was only a defect in a small number of units, but it affected confidence in every battery from that entire manufacturing process category. 

If just one of these C9000 chargers results in a fire or some less significant problem because the average consumer leaves it running unattended...it would devastate MAHA & TD's reputation, or worse if legal actions ensued against them. The Sony battery disaster forever changed the battery safety issue, and IMHO, companies now have a higher hurdle of safety/performance responsibility.

There is nothing that I see worth defending about the old, non-terminating versions. After the Sony fiasco, I would urge TD/MAHA to pro-actively seek out their customers who bought the early version of the C9000 and C900 chargers, and notify them of a recall. They know who they sold them to, and also could put something prominent on their websites about the issues.

Remember the average user who buys a product does not spend endless hours scouring all the forums where you learn the kind of details and proper battery recharging care that some have here at CPF & RC forums. There is no warning anywhere in this C9000's documentation to even look for something like excessive heat, splitting wrapper, or non-termination of a charge.


----------



## SilverFox

Hello LuxLuthor,

I think we can all agree that something changed.

Maha chose to call it an improvement.

In all of our minds, we view it as a revision.

Out of respect to Maha, I will continue to call it an "improvement."

I only have around 30 different brands/sizes of cells that I tested on both the original C9000 and the improved C9000. I take very good care of my cells and have an active regime to insure that they remain healthy.

In spite of all of my efforts to keep my cells healthy, I had 4 of my PowerEx 2500 mAh cells get very hot while charging. These cells are about a year old, have been formed, are stored in a discharged condition, are cycled every 30 - 60 days, and have not been used for anything but testing. The other 8 of this batch are used in my PT Yukon Extreme headlamp. When I tested them, they did just fine and did not heat up.

Why did 4 of my 12 PowerEx cells heat up and split the shrink wrap? Why didn't the other 8 do the same thing? Same charger, same charge rate...

I have to lay at least some of the blame with the cell. I happen to know that there is a problem with some batches of the 2500 mAh cells, so I will lay a good portion of the blame on the cells.

However, if Maha does revise the C9000, I think they should improve the hot cell detection aspect of the charger... Perhaps they already did this. I don't know because I can EDIT: Oops, I ment that I can NOT ENDEDIT: get cell hot enough to come close to the high temperature cut off point since the improvements.

Tom


----------



## LuxLuthor

I agree that some of the blame may lie with the individual cells, but then my question back to you is why did the splitting not happen with the same batteries on your previously used charger model(s)?

I cannot agree that this is "an improvement." It is a fix for a defectively performing charger. Fixing a defect is clearly a significant revision. Saying it is an improvement implies that the previous version was working fine, and some nifty new features were added as a 'bonus enhancement'. The defect in the early model was a problem with overheating, and failure to terminate good quality cells. (I'm sure my PowerEx 2200 cells are still in a good status)


----------



## SilverFox

Hello LuxLuthor,

The BC-900 does not allow charging at 2000 mA, and the Schulze automatically adjusts the charge rate according to the cells condition.

Tom


----------



## LuxLuthor

SilverFox said:


> Hello LuxLuthor,
> 
> The BC-900 does not allow charging at 2000 mA, and the Schulze automatically adjusts the charge rate according to the cells condition.
> 
> Tom



Tom, I don't know what that means vis-a-vis our discussion of new revisions to fix model defects.


----------



## SilverFox

Hello LexLuthor,



LexLuthor said:


> _
> I agree that some of the blame may lie with the individual cells, but then my question back to you is why did the splitting not happen with the same batteries on your previously used charger model(s)? _



I was simply answering your question of why the cells didn't have problems on my other chargers.

Tom


----------



## 3rdDerivative

It was a tweak. And I suspect they will need to tweak again, unless they revise their 'improvement" methodology.


----------



## TorchBoy

SilverFox said:


> I don't know because I *can* get cell hot enough to come close to the high temperature cut off point since the improvements.


Do you mean you "can't get cells hot enough"? That's great. My C9000 gets AAA cells too hot to touch even at 0.5C, and I never had that before using a GP Powerbank charger. Interestingly, and sadly, an identical GP charger (I gave my own one away when I got the C9000) now rejects some of them. With so many variables I'm a bit hesitant to point the finger but my confidence in the old version certainly isn't as high as it should be.


----------



## webfors

Hi Tom,

all 8 of my old 'unhealthy' nexcell 1800mah batteries terminated perfectly in the new version of the c9000. It's charging the really old Titanium 2300's now.

This is definitely an improvement. And please keep in mind that I also used the lowest charge rate of 200ma.


----------



## SilverFox

Hello Ian,

Thanks for catching that. I have edited my post to reflect that I can NOT get cell hot enough...

AAA cells do not seem to be as well built and well developed as AA cells are. If you are seeing high cell temperatures at a 0.5C charging rate at room temperature, I would suggest that your cells are "crap," and you should recycle them.

You may want to try a Break-In, followed by a few cycles. Sometimes you can recover a cells performance. Other times you can't.

Keep in mind that a cell heats up more if it has higher internal resistance. This goes for both charging and discharging. I don't know what the current draw on your cells is, but if it is approaching 0.5C, they are heating up during discharge as well.

Tom


----------



## SilverFox

Hello Webfors,

Excellent news...

Tom


----------



## patycake57

Well, I ordered a C9000 one week ago this Friday from TD, and received it Wednesday. It had 0FAB01 on the bottom. It seems ok on AA, but has missed 6 terminations on AAA batteries at .5C and were pretty hot to the touch when I pulled it out. I didn't see if it would stop at 4000 vs 20000 mAh. Sounds like I got the original model. These aren't "quality" AAA, but my 401FS did not do this (ignorance is bliss). Does anyone have official word that 0G0B01 is the newer model? If there is confusion on this matter at MAHA, I might just go for a straight return rather than some lottery.


----------



## SilverFox

Hello Patycake,

I suggest that you call Maha at 800-376-9992 and ask them why you did not get the improved charger.

Tom


----------



## wptski

We are running into the same problem with the C9000's as the BC-900's! Two different versions out there! I'll have my two replacements on Monday, I hope that I get the newer ones.


----------



## webfors

All 3 really old, and unhealthy titanium 2300's all terminated fine at 200ma. 

Now I'm off to test my AAAs


----------



## SilverFox

Hello Webfors,

One more thing...

When you insert a cell and select a charge rate, the display will show the charge rate, then it shows a higher voltage. This is the internal resistance check on the cell. This voltage ranges somewhere between 1.45 - 2.50 volts.

What voltage are you seeing with these "problem" cells?

Tom


----------



## Anders

Hello Tom.

I have always wanted to know what that numbers mean.

I inserted some of my AAA cells now, the highest number i got was 1,97 V, i think it is the cell with the highest internal resistance, right?

Anders


----------



## SilverFox

Hello Anders,

I am not sure just what it means, but it seems that HIGH displays when that value is over 2.00 volts.

The Energizer 15 minute charger won't charge cells that have over 0.100 ohms of internal resistance. I just happen to have a couple of cells that are very close to that and when I stick them in the C9000 they show 1.7 volts.

I have some Titanium Power Max 1800 mAh cells that have an internal resistance of 0.014 ohms. When I go to charge those cells I get a value of 1.45 volts.

A lot of my cells have 0.030 ohms of resistance and they show 1.62 volts. Others coming in at 0.044 ohms show 1.59 volts.

I may be so bold to suggest that, based on limited preliminary observations, you may want to choose lower charging rates with cells that show 1.7 volts or over during the internal resistance check on the C9000. 

This may also enable us to judge the condition of our cells...

Tom


----------



## Anders

Thankyou Silverfox for your fast reply.

Interesting..., with "lower charging rates" I suppose you mean around 0,5 C?

I have the oldest version of the charger and i think i get more safe charging terminations with a little more than 0,5 C, i usually prefer 0,7-0,9 C. Do you suggest me to lower the mAh with cells with higher V readings to avoid the cells to get hot and still be over 0,5 C?

Anders


----------



## SilverFox

Hello Anders,

I don't know for sure, but yes, I think so...  

When charging at 2 amps, the charger gets hot and the cells pick up some of that heat. If the cells have higher internal resistance (what I am calling "unhealthy" cells), they will they will heat up more than cells with lower internal resistance.

At lower charge rates, the internal resistance effects is less significant.

I hope that makes sense...

Tom


----------



## Anders

For sure it does Tom, thanks.


Anders


----------



## LuxLuthor

More good information, Tom. Hey a somewhat unrelated question, without paying a fortune, do you have a recommendation on a good resistance tester. Right now, I'm just using this Radio Shack $20 model to at least get voltages.


----------



## EngrPaul

Got my 0G0B01 today. Put in 4 AAA Powerex 1000's and it recognized them right away. My 0FAB01 would take 20 seconds or more. 

Also you know I had some termination issues with AAA batteries. I'm hoping this is all better.

The only strange thing is that it's harder to put in AAA batteries, especially in slot #4. I think the terminals drift downward left to right. I'll have to keep an eye on this.

Cheers to Thomas Distributing and MAHA Energy.


----------



## LuxLuthor

I was hoping to get mine today, but no luck yet.


----------



## Bear

Hi everyone!

This is my first post. I had been lurking around here for about a year and I finally decided to join. Thanks to this site I have learned a lot about flashlights, batteries, and chargers. Thanks to everyone - and especially SilverFox for his thoughtful commentaries!

I bought a C9000 late December and I have had no problems with it except that it doesn't acknowledge the presence of certain batteries, and of course the 2A charge does warm 'em up a bit when all 4 are going. Oddly enough, I found out why certain batteries don't "take" by accident. When inserting a battery more horizontally than at an angle, it "took." I couldn't repeat this but I did find the reason for it. There are two prongs that stick out of the positive terminal contacts of the C9000. On certain batteries these prongs can straddle the positive electrode of the battery. I took a little bit of tin foil and put it over the batteries' positive electrodes and then carefully inserted them into the charger and voila! - they then registered on the C9000.

I don't think there is an issue with the prongs though. Probably with just a little bit of use their sharp points will wear down enough to mate with any battery.

One data pont for Silverfox: I did notice once that an initially displayed voltage surpassed 2.00, actually 2.02, and the charger "took it" and did not display HIGH. I agree that the 2V is probably a good number though, I am just noting that there is a little wiggle room there.

One other thing about the 2A charge. This doesn't apply to the improved version as much as the initial version of the C9000. When I want to charge 4 cells at 2A I just put them into the charger in sets of 2 each staggered by about 5 minutes or so and I also put them in non-adjacent bays. Most of the temperature rise at 2A seems to be in the last minute or two. For cycling I suppose one could vary the discharge rates a bit so that the cells won't all heat up at the same time. FYI.

Good day!!


----------



## webfors

SilverFox said:


> Hello Webfors,
> 
> One more thing...
> 
> When you insert a cell and select a charge rate, the display will show the charge rate, then it shows a higher voltage. This is the internal resistance check on the cell. This voltage ranges somewhere between 1.45 - 2.50 volts.
> 
> What voltage are you seeing with these "problem" cells?
> 
> Tom



Hi Tom,

they vary between 1.6 and 1.9 volts. Out of these same 11 batteries, 5 of them did not terminate on the first c9000. All of them terminated fine on the new charger.


----------



## SilverFox

Hello Bear,

Welcome to CPF.

Thanks for adding to our database of voltages. The highest I have seen has been 2.45 volts. That cell just kept reseting and did not even display HIGH. Any idea what that voltage means?

Another data point... I just stuck an Alkaline Duracell AA cell in. It came in at 1.95 volts, charged for 3 mAh, then indicated DONE.

Good tip on staggering the cells when charging at 2 amps. That should help a lot.

I took my original unit apart and put a small square of black electrical tape on the back side of the + posts. This pushed them a little bit forward and I eliminated any problems with cells not being recognized when inserted.

Tom


----------



## wptski

SilverFox said:


> Hello Bear,
> 
> Welcome to CPF.
> 
> Thanks for adding to our database of voltages. The highest I have seen has been 2.45 volts. That cell just kept reseting and did not even display HIGH. Any idea what that voltage means?
> 
> Another data point... I just stuck an Alkaline Duracell AA cell in. It came in at 1.95 volts, charged for 3 mAh, then indicated DONE.
> 
> Good tip on staggering the cells when charging at 2 amps. That should help a lot.
> 
> I took my original unit apart and put a small square of black electrical tape on the back side of the + posts. This pushed them a little bit forward and I eliminated any problems with cells not being recognized when inserted.
> 
> Tom


Tom:

The higher the impedance the hiigher the required charging voltage. Maybe it compares the required voltage to produce the set current?


----------



## coppertrail

The following are results for a set of 4 Sony 2700 mAh cells that came with a Sony charger I purchased in Mid Jan. I've not charged these cells prior to receiving my replacement Maha charger. Here are the results from a break in mode followed by a 1 cycle mode:

Break-In Mode 2/28/07

1. 2633 mAh	1.40V
2. 2611 mAh	1.39V
3. 2620 mAh	1.40V
4. 2651 mAh	1.41V

Cycle Mode (1 Cycle) 3/3/07

Charge rate: 1400 mA
Discharge Rate:	500 mA

1. 2646 mAh	1.43V
2. 2619 mAh	1.43V
3. 2629 mAh	1.43V
4. 2667 mAh	1.43V


----------



## Litec

Hello friends,

Though I have just signed in as a new member, I have been regularly reading the CP Forums.

My C9000 is from the very first lot shipped by TD. Though I have not extensively tested the charger, it does have termination issues on AAA and sometimes on AA cells too. It is rather strange for a company like Maha to release a advanced charger without extensively testing it. Though they may exchange it with this new 'revised' model, this certainly increases the headache, not only for them but also for us.

Again, who knows, this one too maybe 'imperfect' so to say. Maybe Maha have quickly done a few software mods due to the heat generated in this forum. Now this 'revised' charger, if it misses termination, will stop charging after pumping in 4 amps into any cell. It is quite possible that we may soon have AA cells that are more than 4AH. Then what do we do? Remove the cells and put them back again to charge, or possibly get another charger !!

Some members have mentioned that the new version shows 'Done' on almost all the cells. We will have to ensure that 'Done' definitely means the cells are 100% charged, and not 80 or 85%.

VJ


----------



## SilverFox

Hello VJ,

Welcome to CPF.

The original C9000 has issues of missed terminations when charging at lower charge rates. It seems that some cells do not exhibit the voltage drop that the original C9000 is looking for to terminate the charge. Maha noticed this during their testing, but I think they wanted to present a charger that charged cells to their fullest. 

My personal opinion is that if you are charging at 0.5C and the cell does not give a good end of charge termination signal, your cell is unhealthy and should be replaced, even if there is more life left in it.

However, charging to a fuller charge also increases cell temperatures, and the C9000 when charging at 2 amps heats up as well.

The improved C9000 does not charge as full as the original unit did. Our guess is that it is using a very similar termination algorithm as what is used on the C808M charger. The result of this is that the cells don't get quite a full, but every cell terminates, and the temperatures have come down a little.

I believe the 4000 mAh AA cell is a long way into the future, and will just point out that all of the other chargers have a lower time limit than that. For example, the BC-900 has a 3000 mAh limit.

We are just receiving the improved C9000 units. You may want to hold off doing anything until we see if any other issues surface.

One way to check part of the health of your cells is to pay attention to the voltage displayed as soon as you insert the cell for charging. We have noticed that cells with higher internal resistance show higher voltages during that test, get hotter during the charge, and can have issues with termination. Cells that show around 1.7 volts are rejected on the 15 minute chargers and that value seems to be around 0.100 ohms. 

If you don't mind, could you share what values you are getting with your cells that are not terminating?

Tom


----------



## dekelsey61

Tom,
If you are right about Maha knowing about this problem during testing then why would a company that produces fantastic products release a product that will not work properly and put there reputation on the line? If a battery does not charge as full I can care less at least you will not be damaging your batteries by alot of heat by the missed terminations. I believe you ran into this problem with the shrink wrapper melting because the batteries did not terminate. Maha did replace your batteries. I would rather have a charger that does not fill as full of a charge than a charger that gets a full charge but you have to worry about if the battery will terminate or even get really hot.
Dan


SilverFox said:


> Hello VJ,
> 
> Maha noticed this during their testing, but I think they wanted to present a charger that charged cells to their fullest.
> 
> 
> 
> Tom


----------



## Anders

Hello.

It seems that i also soon will have the new improved version of the C9000.

I bought my C9000 from thomas-distributing and a CPF-member was so kind that he sent it to me.

I had a few termination issues and finally yesterday the charger doesn't work at all, the third slot always are marked as it already have one cell in it and is waiting for my command.

Here in sweden i read in a forum that MAHA have a new agency so i contacted them and told them that i bought my charger in US and i asked them if i could send it to them to get a replacement.

They told me that it is a 3 year warranty on chargers here and they are happy to help me, they also told me that they have the new improwed model, that is what i call goodwill 

Anders


----------



## SilverFox

Hello Dan,

The issue that I had with melting the shrink off my PowerEx 2500 cells was not due to termination problems. All 4 cells properly terminated. It was a cell problem. The heat was generated because there is a problem with 2500 cells and they seemed to develop higher internal resistance. High internal resistance + high charge rates = high cell temperatures.

I was unable to get any of my batteries to miss a termination when charging at the rates I usually use. I had to borrow "crap" batteries from a neighbor and reduce the charging rate to a low rate before I was able to observe a missed termination. The same "crap" cells also failed to terminate at the same charge rate on the BC-900.

So, the question is if the problem lies with the charger or the condition of the cells...

We at CPF tend to be very anal about our lights and the tints of our LED beams. I just happen to be very anal about my batteries.

However, if everyone was as anal about their batteries as I am, we would never have discovered the termination issues. I guess it is a good thing that some people hold on to their "crap" batteries...  

Tom


----------



## SilverFox

Hello Anders,

Just to be clear, your 3rd slot would try to initialize even though there was no cell in it. Is that correct?

I have had a slot continue to initialize with a cell that had very high internal resistance, but not what you are saying.

It is good to hear that you are being well taken care of.

Tom


----------



## Anders

Silverfox wrote: " Just to be clear, your 3rd slot would try to initialize even though there was no cell in it. Is that correct?"

Exactly Tom, then the charger turn off and then on over and over again.



Anders


----------



## dekelsey61

Tom,
I don't believe this issue of missed termination is because of "Crap" batteries.
I have 8 Sanyo 1000Mah AAA battteries. They are less than 3 months old. Only 2 batteries out of the 8 terminated with my older C9000 charger. I was using the recommended 0.5C rate. When I received my newer C9000 version I charged them the same way and all 8 terminated just fine. I had very few AAA batteries that would terminate with the older model. With the new one All AAA batteries terminate with no problems.
Dan


----------



## sylvainp

Well I have made some test with my c9000 (0FAB01) with 4 AA PowerEX 2500.

I discharge them and after I charge my battery with a 200mah charge rate.
After over 900 minutes and about 3000 Mah the battery where not terminated.

They were barely warm too.

After I take the battery off the charger and charge them at the default charge rate (1000 mah) and within a few minutes they fully charge.

Does this mean that at low rate charge the battery will never terminated with this charger ?

Does the new improved model 0G0B01 will terminate charge at this low rate (200 mah) ?

Maha is sending me the 0G0B01 model to replace mine.


----------



## SilverFox

Hello Dan,

It very well could be that my definition of "crap" cells is different from yours.

In my humble opinion, if you took your new cells, ran them through a Break-In cycle, let them cool down for around 30 minutes, did a discharge and once again let them cool down for around 30 minutes, then they failed to terminate during a 0.5C charge using negative delta V termination, there very well could be something wrong with your cells. Once again, in my humble opinion, healthy cells give a strong end of charge signal after they have been properly formed.

It is my humble opinion that brand new cells are the most difficult to charge, followed closely by cells that have been in storage.

Speaking of brand new cells...

I had 8 "crap" cells out of an order of 150 very high quality premium cells.
I had 3 "crap" cells out of an order of 12, also very high quality cells.
I have 20 "crap" cells out of an order of 20, with one of them being really "crappy."

And this is just in the last few months.

These cells all had performance issues after being properly formed and were cycled to observe if there was any chance for improvement. They were "crap" after forming and continued to be "crap" during and after cycling.

Understand, that I also have had orders where all the cells were good. However, just because batteries are brand new does not mean that they can't also be "crap." 

As far as the improved C9000 goes, I don't know what Maha did, but it looks like missed terminations are a thing of the past. 

I must admit that I don't have an answer to the lingering question as to why the terminations were missed. I think there is something strange with the chemistry of the cells. 

I will admit that there may have been something wrong with the charger, but then, why did my cells, both AA and AAA, terminate properly... On the other hand, there was at least one incident of Eneloop cells not terminating. Those cells have not been stored for extended periods of time, and seem to be very consistent in quality.

The questions linger, and the only answer that seems to come close to fitting is that people had some "crap" cells.

Tom


----------



## SilverFox

Hello Sylvainp,

Let's see now, charging 2500 mAh cells at 200 mA works out to a charge rate of 0.08C. The battery manufacturers recommend a 0.5 - 1.0C charge rate when using negative delta V termination. 

At the low charge rate, there is no signal to end the termination, so it would continue to charge until you reached the time limit.

We have been unable, so far, to get the improved C9000 to miss a termination. It is possible to have a missed termination at such low rates, so use them at your own risk. You should be fine with the default charge rate with the 2500 mAh cells though.

Tom


----------



## FsTop

*"Improved" Maha C9000 ?*

A question - I am using Eneloop AAA's in my first-batch C9000 and I have not seen any sign of termination issues in a couple of dozen cells - they all charge at the same rate, and finish within 25 mah of each other. 

If I ever did see such a problem occur, I'd toss the cell anyway just on general principles - anything electrically different about one particular cell is highly unlikely to be a good thing, as is heating up due to late termination.

So, is there any reason why I should "upgrade" to a newer version of the C9000 that charges to a level 3% less than the original, or am I misunderstanding something?


----------



## jeffb

I have had no problems with version 1. E-mailed Maha and they wish to know what issues I have had................I presume that they will not replace if I haven't had problems?

Any suggestions, appreciated.

Thanks,

jeffb


----------



## SilverFox

Hello FsTop,

That is a tough question.

I have two units, one original, and the other is the improved version.

I debated for a long time weather I was going to send in my original unit or not. I finally did.

My issue with the original unit involved cells overheating. I was informed that the improved version includes improvements in the cell temperature monitoring, as well as improvements in the charge termination. That is why I upgraded.

Tom


----------



## SilverFox

Hello Jeffb,

If you decide to go for the improved unit, just tell them you are concerned about charge termination.

Tom


----------



## LuxLuthor

Tom, I still don't understand why the failure to terminate with earlier models has to be something related to "crap batteries" as you assume. 
It could be that some cells are still within acceptable operating margins, but moving towards the limits of what is considered a good battery. There was obviously something that MaHa recognized in their early versions that they changed in all subsequent units, and readily pay the expenses of an exchange.

The 2 PowerEx of the set of 4 AA 2200 mAh were all bought at the same time, used in the same MP3 player, and ALWAYS charged together, either in the player with it's 600 mA 9V charger, or about once every 5-7 weeks, removed and charged as a set in my MH-C401FS. There was never any change in the performance of the cells as a set, and the Archos has an exact battery charge AA mAh specifier in the RockBox software, with remaining battery life indicator display.

It made no sense to me that two of them failed to terminate after 5000+ & 6000 mAh pumped into them. I discharged all 4 on the C9000, then recharged them in my old C401-FS, and they still work fine after two more play/recharge cycles. I just don't have the direct experience to backup your theory that "crap cells" are the cause of the non-termination.


----------



## wptski

LuxLuthor:

Do you remember which slots these cells were in that missed termination?


----------



## SilverFox

Hello LuxLuthor,

My theory of "crap" batteries causing the charger to miss terminations when charging at lower rates comes from what I experienced during testing the charger.

I ran tests on the cells that I have, at the rates I normally use for charging, and had no problems at all with termination. I did have a set of batteries get very hot, but they did terminate, and upon checking the mAh put in, they terminated properly. 

It was not until I obtained some cells from others that I was able to duplicate the missed terminations. Upon checking the cells that did not terminate, I realized that they were "crap" cells, from a performance perspective. Their capacity had dropped, and their impedance was higher than any of my cells.

It very well could be that I am missing something here and am totally wrong, but until someone brings forward a better explanation, I am sticking to the theory of "crap" cells.

Tom


----------



## Perfectionist

Looks like a great charger ..... if only it did Lion and PP3 cells too !!


----------



## Litec

Hello Tom,
Thank you very much for the reply. I have not carefully observed the values on the cells that do not terminate. As soon as I get the results again, I will be very glad to share the same with all.
Regards
VJ


----------



## LuxLuthor

wptski said:


> LuxLuthor:
> 
> Do you remember which slots these cells were in that missed termination?



Slots 2 & 3 while charging all 4 from the set. Yes they got extremely hot, but I did not notice any splitting of the wrapper, but got painful to the touch after a few seconds. I didn't get my replacement charger today.


----------



## J_Oei

I just called Thomas Distributing about exchanging my charger for the "improved" one and they told me to contact Maha.

What did I do wrong?


----------



## dekelsey61

Hi Tom,
What other changes did Maha do to this charger. You seem to be dropping little Improvements every now and then. I really do love my Newer versions of the c9000. Thank you.
Dan




SilverFox said:


> Hello FsTop,
> 
> That is a tough question.
> 
> I have two units, one original, and the other is the improved version.
> 
> I debated for a long time weather I was going to send in my original unit or not. I finally did.
> 
> My issue with the original unit involved cells overheating. I was informed that the improved version includes improvements in the cell temperature monitoring, as well as improvements in the charge termination. That is why I upgraded.
> 
> Tom


----------



## SilverFox

Hello Dan,

About the only other thing I have noticed is that the delay time from the time you insert the cells to when it starts charging with the default settings, seems to have been extended.

With the original unit, it seems like I had to rush through the process, and sometimes it had already started charging the 4th slot by the time I got to it. The improved unit seems to give me ample time. 

On the other hand, I may just be getting quicker at getting things underway...

Tom


----------



## wptski

I got my two C9000 replacements today! First run on 2.3Ah Duracells discharged at 1A and charged at 2A. Not this set but two other sets with the unimproved version, the center two slots would finish first and appear to be terminating early, not so with this one as the outer cells finished first. The last to finish was Slot#3 but my IR imager showed a max temperature of 155F at the positive end which is normally a bit warmer. It still gets hot!!

This early termination has happened with certain brands and capacities so far. PowerEx 1.8Ah and Duracell 2.3Ah but not Energizer 2.2Ah. If you look at my Impedance Graph thread you'll notice a big difference between the 2.3Ah Duracell and the 2.2Ah Energizer cells while charging too!!


----------



## TorchBoy

Tom, does the new version have this feature?










This is how my second C9000 reports the results of the first cycle (my first C9000 developed the continuous restart fault on slot 2). This latest aberration appears on slot 1 only, on the first of either 2 or 3 cycles (tested so far). The photos are after:
0.5C (400mA) discharge [5 5], and
1C (800mA) discharge [4 4].
Presumeably the runs gave results in the 5XX and 4XX range. Don't know if it's the same cell as the photos were taken some time apart. I've found it's quite repeatable.


----------



## SilverFox

Hello Bill,

Wow, that's hot. That is not much of an improvement.

Is the cell OK? What kind of impedance are you getting with it?

If you discharge it and charge it again in does it get hot again?

Questions, questions, questions... 

Tom


----------



## SilverFox

Hello Ian,

I have not checked cycling with the improved unit. I will run a few cycles and get back to you.

Tom


----------



## wptski

SilverFox said:


> Hello Bill,
> 
> Wow, that's hot. That is not much of an improvement.
> 
> Is the cell OK? What kind of impedance are you getting with it?
> 
> If you discharge it and charge it again in does it get hot again?
> 
> Questions, questions, questions...
> 
> Tom


Tom:

Impedance for all cells were 35-40 mOhms range. I will retest tomorrow.


----------



## 3rdDerivative

Whatever happened to the Maha representative?


----------



## LuxLuthor

3rdDerivative said:


> Whatever happened to the Maha representative?


----------



## AndyTiedye

My old version just cooked the shrink wrap on one of my cells.
They were all hot hot hot! being charged at 1000 ma.

I just sent email to Thomas to see about getting one of the new ones.


----------



## sylvainp

I'm not lucky ! Yesterday DHL passed home to deliver my C9000 replacement but i was not there.

This morning pass again and I was sleeping like a bear because I never heard the door ring ! Well, I will need to go pick it up on wednesday or thursday.

Wow that was fast from MAHA ! I live in Montreal so this is really fast service !

Can't wait to test the new C9000 !


----------



## TorchBoy

Add me to the list of people who now have a 0G0B01. Yay! I'm testing to see if it has the missing digit problem. The first thing I noticed (apart from the version number) was the screen position, avoiding the black band down the left side.

Earlier today I found one of my AAA cells was doing a Termination Roast (TM) at 1340+ mAh into a partially charged 800 mAh cell. In the 0FA reinserting after a rest and continuing the charge would have given it at least 70 mAh more, and 11-15 minutes. The 0G0 gave it just 1 mAh. I think I'm going to like this version. I'll have to get some new AAA cells to replace my cooked cells tho.

And FWIW I think 2.08V is the magic impedance-related figure (in 0FAB01). Investigating with some (by Tom's definition  ) "crap" AAA cells shows sometimes 2.08V is deemed HIGH, sometimes it's not. Would that figure be the only thing it's going on?

And another thing - I've seen 1.52V while charging on 0FA climb to 1.53V, stay there awhile, then drop to 1.52V. Termination was a few minutes later. Do I spend too much time looking at that screen?


----------



## wptski

Tom:

I just took the same 2.3Ah Duracells, discharged at 1A and charged at 2A in the same slots. The exact same sequence in finishing happened again with Slot#3 finishing last and getting to 157F. A closer look at the IR image of the same slot yesterday actually showed 159F. The plastic area around the temperature metal contact gets to 132F.

I'm going to discharge them again but this time rotate the cells in the slots.


----------



## TorchBoy

Bill: How long do they spend being that hot? Is it just at the end that the temperature skyrockets or do they spend ages up there?



sylvainp said:


> I'm not lucky ! Yesterday DHL passed home to deliver my C9000 replacement but i was not there.
> 
> This morning pass again and I was sleeping like a bear because I never heard the door ring ! Well, I will need to go pick it up on wednesday or thursday.
> 
> Wow that was fast from MAHA ! I live in Montreal so this is really fast service !


Yep, Judos to Maha for their quick service. NZ Post on the other hand needs 

Exactly the same size box as my previous replacement, which was delivered to my doorstep, but this one I had to go to the post office to collect. Seems somebody had decided the postie could carry it on her bike instead of it being carted in a delivery van. The postie (rightly so) had other ideas.


----------



## wptski

Ian:

Well, I didn't log the temperature but to give you an idea, Slot#2 finished three minutes earlier and it was still 148F when Slot#3 finished.


----------



## bmoorhouse

Bill,

Just to confirm, is this overheating you are seeing happening with one of the new models? I thought it was supposed to have a cut-off feature at 132 degrees or something like that. If it is a new one, I'd guess either you have found something MAHA didn't fix with the current revision or you have a bad unit. As I wanted to order one of these new models, I am hoping you just have a bad one.


----------



## sylvainp

what you guys are using to record the heat generated by the battery ?

Infrared heat sensors ?


----------



## wptski

Tom:

Geez, I don't know which thread to post in! 

I just discharged four Sanyo 2.7Ah cells at 1A and charged at 2A. They all finished within four minutes of eachother and the maximum cell temperature of the middle slots was 128F. Of course these are larger in capacity than the 2.3Ah Duracells that reach 160F but I don't think that the difference in capacity would account for all the extra heat.

I think that I graphed these in the Impedance Graphs thread. I think that it's still something to do with the way a Duracell reacts impedance wise while charging.

bmoorhouse:

Yes, I received two improved replacements yesterday! It's supposed to cutoff at about that but the sensor is at the negative end which stays cooler and I think that if the sensor reaches 132F the cell will be toasted by that time!! The temperatures I quote are from the positive end.

I forget who asked. I'm using a infrared thermal imager.


----------



## sylvainp

wptski said:


> I forget who asked. I'm using a infrared thermal imager.


 
Geez that must be expensive ?


----------



## wptski

sylvainp said:


> Geez that must be expensive ?


Yes it was even with a very good deal. I lost several nights sleep over it!


----------



## SilverFox

Hello Bill,

Temperatures around 128 F are what I have been seeing...

Could there be something strange with the Duracell cell?

Tom


----------



## TorchBoy

I haven't seen the "5 5" problem in the new version... but I did get this instead.






It was discharging at a pretty steady 100mA and the voltage was fluctuating between 0.95 and 0.96 volts. A new way of discharging cells?


----------



## sylvainp

TorchBoy said:


> I haven't seen the "5 5" problem in the new version... but I did get this instead.
> 
> 
> It was discharging at a pretty steady 100mA and the voltage was fluctuating between 0.95 and 0.96 volts. A new way of discharging cells?


 
If i'm right, when you are discharging battery the voltage shown is the battery voltage. Usually it should never go below 1.00 volts which is the discharge voltage for rechargeable battery.

So far for all my cells I never see volts below 1.00 for discharging and higher than 1.52 for charging.


----------



## TorchBoy

Oops, I spoke too soon. It does still do the "5 5" thing. Only on slot 1, on the first of 2 or more cycles.

Also, I've seen 0.99 volts on (I think) slot 4.


----------



## sylvainp

TorchBoy said:


> Oops, I spoke too soon. It does still do the "5 5" thing. Only on slot 1, on the first of 2 or more cycles.
> 
> Also, I've seen 0.99 volts on (I think) slot 4.


 
What is the 5 5 problem you are talking about ? I just don't understand can you explain this bug ?

Thanks


----------



## meeshu

Have a look at post number 142 in this thread.

It appears that the middle digit is not being displayed on the charger screen. For example, instead of 535 mAh, the display will only show 5_5mAh; the middle digit 3 is missing.

Presumably the charger display and/or associated driver/logic circuitry may be faulty!?


----------



## TorchBoy

I don't think it's that the middle digit is missing. I think the first digit is repeated after a space. Hence "5 5" and "4 4" are the *only* examples I've seen, and several times each. It's pretty unlikely that each time the first and last digits were the same. This is supported by a run on the new model C9000, where the actual result was 503mAh* but still shows 5 5 looking at the cycle result.

* As viewed during the rest just after the discharge. Is this a new feature? I don't recall that the value showed then on the old model, just 0.

Sorry, I'm playing around with my web site at the moment so the pics don't show in post 142. Here are the two pics again.


----------



## wptski

Tom:

Yep, something to do with the impedance of the Duaracell and being heated by the charger I think. I'm going to charge those same ones on my C808M tonight and see what happens.

The Sanyo cells had a higher impedance but as my graphs show, they act differently during charging.


----------



## TorchBoy

OK, I think I've got a handle on the CYCLE discharge. The new version holds the selected discharge current instead of tapering off like the old version, and it discharges to 0.90V instead of 1.00V. Nice. Makes it a much more accurate tool. (Although it makes my cells look sucky.)


----------



## LuxLuthor

Why would they make that happen with the cycles mode down to 0.9 but not on regular discharge?


----------



## TorchBoy

LuxLuthor said:


> Why would they make that happen with the cycles mode down to 0.9 but not on regular discharge?


:thinking: :shrug: I'm giving the other modes a try.

It looks like the voltage is not the full story for impedance HIGH failure. I've just found a cell that was rejected with HIGH at 2.07 volts so I stuck it straight in again and requested the same Refresh Analyze. This time it got 2.08 V but accepted the cell.


----------



## wptski

Tom:

I charged those same 2.3Ah Duracells in the C808M after discharging them. Three cells finished with a couple minutes of eachother at 104F but the forth in Slot#2 went another ten minutes and got to 133F. Still better than the C9000.

The cell that went longer didn't have the highest impedance of the four either! I have no idea why it took longer to finish!! It wasn't the cell that went the longest in the C9000 either!!


----------



## SilverFox

Hello Bill,

Interesting, I think we are seeing a trend here. Those cells seem to heat up more at higher charge currents.

What happens if you charge at 500 mA on the C9000? Will it terminate?

Tom


----------



## wptski

SilverFox said:


> Hello Bill,
> 
> Interesting, I think we are seeing a trend here. Those cells seem to heat up more at higher charge currents.
> 
> What happens if you charge at 500 mA on the C9000? Will it terminate?
> 
> Tom


Tom:

The improved version is different as the 2.3Ah Duracells in the center slots instead of terminating a bit early at 2A finish last and got hot to boot. Like fix one bug but add another!

They did at 1A on the unimproved version and all four about the same time too. I'll try .5A but first I have a set of 2.65Ah Duracells to try tomorrow.


----------



## webfors

TorchBoy said:


> I don't think it's that the middle digit is missing. I think the first digit is repeated after a space. Hence "5 5" and "4 4" are the *only* examples I've seen, and several times each. It's pretty unlikely that each time the first and last digits were the same. This is supported by a run on the new model C9000, where the actual result was 503mAh* but still shows 5 5 looking at the cycle result.
> 
> * As viewed during the rest just after the discharge. Is this a new feature? I don't recall that the value showed then on the old model, just 0.
> 
> Sorry, I'm playing around with my web site at the moment so the pics don't show in post 142. Here are the two pics again.




FYI: I've seen this phenomena on my first revision of c9000, when cycling 4 batteries and attempting to view the cycle info after2-3 cycles. Haven't seen it on my new revision yet.

Regarding the high temps Bill has seen, I have yet to see such high temps. I do admit my newly purchased px 2000mah (could have been sitting for some time before I got them) heat up more at 1 amp then my px 2700's do at 2amps. Looks like the high capacity batteries can handle the c9000's 2 amp charge just fine. However, I have yet to experience any really high temps with the new version. I do wish I had a method to accurately test the charging temps. My advanced two finger touch test tells me the batteries are only warm, and spike to 'almost hot' for a brief moment at the end of the charge cycle, and cool down quickly. 

The temps noticed on my c9000 are definitely lower then my 204w, which I've pretty much shelved in favour or other chargers, like my LP4000N


----------



## wptski

webfors:

Only further testing will prove wether it is brand, capacity or what sensitive. Something is going on here that's for sure. I'm not sure if the improved version is really unimproved or try to fix one problem and cause another one!

We've seen problems with termination when charging at low rates with larging capacity cells but this would be a first where a charger has a problem with a certain brand and maybe the capacity!


----------



## webfors

keep us posted on your tests. I'm curious to see what variable(s) are the cause of the high temps. I sure hope it's not the charger.. but then again maybe Maha will come out with a 3rd or 4th revision that we can swap for


----------



## wptski

webfors:

It is something with the charger but it's also something with the cells to! A 2.3Ah Duracell impedance graph doesn't look like a 2.4Ah Duracell graph. We all know how these companies have cells made by others and but their name on them. They may have went a bit heavy on the garlic!


----------



## bmoorhouse

Ugh. I just ordered a new one to replace the original I sent back. I certainly hope this is a minor problem that doesn't effect all of the chargers - or maybe I need to stop reading this board and just be happy with what I have when I get it . . .


----------



## wptski

bmoorhose:

A charger for the casual user doesn't have a display showing all these values. It's designed to be looked at and watched. That's exactly why these problems have been noticed.

This charger seems to bring out the worst in 2.2Ah Duracells at least when charged at 2A so far! The original unit acted a bit differently at 2A and at 1A with the same Duarcells. Now the improved version acts differently compared to the original unit with those same Duracells. Both versions don't like 2.3Ah Duracells at 2A!!


----------



## SilverFox

Hello Bill,

:devil:  Must be "crap" cells...  :devil:

Tom


----------



## webfors

bmoorhouse,

my dozens of cycles so far, with dozens of batteries, have indicated no problem whatsoever with the new unit. It terminates perfectly, even at very low charging rates (like 200ma, which I don't recommend). I haven't had any batteries overheat.

I think it's a definite improvement. However, don't use Duracell 2.3ah cells, or any other brand made in the same factory, or if you do just charge at 1amp. I don't think there's an absolute need to charge at 2amps with any battery, unless you just want to 'see how it goes'. The heat generated is much lower at 1amp - 1.5amps. Or if heat is really an issue, try 500ma - 800ma. The new charger doesn't seem to have any termination issues at lower charge rates. You get the best of both worlds 

FYI: Flaws will always be pointed out on new products, especially by tech-geeks like us who gotta know everything there is to know about charging batteries.. lol. I still have family/friends who are completely clueless about rechargeables, use alkalines all the time, and are perfectly happy people


----------



## wptski

webfors:

You should be able to charge at up to 1C with no problems at all. Charging at 2A on a 2.3Ah should be no problem. On the original unit, the 2.3Ah Duracells termiated early, now they terminate later and overheat! All of the problem isn't with the charger alone, it's the cells too! I'm just posting my results, bad or good.


----------



## webfors

wptski said:


> webfors:
> 
> You should be able to charge at up to 1C with no problems at all. Charging at 2A on a 2.3Ah should be no problem. On the original unit, the 2.3Ah Duracells termiated early, now they terminate later and overheat! All of the problem isn't with the charger alone, it's the cells too! I'm just posting my results, bad or good.



Agreed. You 'should' be able to, but you don't have to. I probably won't use the 2amp setting on the c9000 too often, except for testing purposes, or if all the bays in my 808m are full. If I'm in a big rush, I'll use my E15 charger

Maha's next move should be to reverse engineer the fancy switching in the E15, and use it to charge at rates of 3-4amps, with very little heat. Maybe a Wizard 2 with user defined charge rates from 200ma to 4amps. I'm still amazed by my energizer 15 minute charger. I find it charges cooler then some 2amp chargers, and for a much shorter charge time


----------



## hank

Hmmm, and the Energizer 15min supposedly works with all kinds of NiMH, while Rayovac's 15-min setup is only with a special battery.

I wonder how many cycles one gets with the fast charge, anyone found info?


----------



## webfors

Hello Hank,

I believe there's a few threads that discuss the E15 and the life cycle of batteries charged exclusively in it. Tom (Silverfox) has posted some of his results. I've only got about 30 cycles on it exclusively with two sets, 2500mah sanyos and the batteries that came with it (Energizer 2200mah). So far both sets are performing great with no decrease in capacity. Now that I have the c9000, I was also able to deduce that my E15 charger provides a fuller charge then any of my other chargers. Pretty neat little device.. as long as you're not anal about your batteries and the possible damage they're getting in the E15. It's really all a mystery still.. I'll see with time. I charge both sets of batteries every day, so I should know by summer how those batteries do.


----------



## bmoorhouse

hank, in one of these threads (maybe this one, I don't remember) there was a long (almost heated) discussion between (I think) Tom and Mike. In one of the posts, one of them mentioned the 15 minute charger and the number of cycles batteries charged using it had in their life. I don't remember the number, but remember thinking it was lousy compared to other slower chargers.


----------



## SilverFox

Hello Hank,

You may find this thread informative.

Tom


----------



## webfors

SilverFox said:


> Hello Hank,
> 
> You may find this thread informative.
> 
> Tom



Nice! I heard of people quoting that thread, but hadn't read it myself. 

My interpretation of your info is that the E15 is not a demonic-battery-killer, as some have posted, but a relatively good trade off in cycle life for seriously fast charging. General day to day battery care/practices could reduce cycle life more then 25 cycles. 

I don't feel so bad using the E15 periodically on all my battery sets now.. a fact I didn't want to admit before heh. There's just something about the fan noise and that funky switching sound that I like.. oh yea, and the 15-20 minute charge time:lolsign:


----------



## wptski

webfors:

Remember that the manual suggested charging between .33C and 1C but we found that you had to charge between .5C and 1C because of termination issues. Now we can't charge at .87C with "certain" cells!! This is a complex issue, charger vs cells.


----------



## sylvainp

Finally I got my replacement C9000 and it have the 0G0B01 number !

The first thing I notice is the extended time we have to select the MODE. On the old one you don't have much time to select the MODE features.

When I put charged battery in the charger it takes less time to stop charging.

I'm doing some test now with AAA Duracell 1000 mah (take less time) and I will test : Cycle, discharge, refresh.

I'll come back to give the results.

So far the rest time is not 60 minutes looks more like 120. I think that 1 hour rest was ok so why extend the rest time to 2 hours ? Is this new standard ?


----------



## webfors

you definitely have to get intimate with the c9000..  It's a good thing the new one terminates correctly at lower charge rates. I've confirmed this with several 'crappy' cells, charging at 200ma and 500ma. All terminated fine with very little heat generated. So the new one appears to give you more options then the original. My biggest pet peeve wasn't the heat at 2amps (which the new version seems to do better as well), it was having to worry about leaving it alone for a few hours with the thought of miss terminations running wild in my head. The new version addressed all my concerns so far. Nothing but good things to say about it.. hope it stays that way :rock:


----------



## wptski

I charged four 2.65Ah Duracells at 2A. All four finished with five minutes of eachother and the highest temperature was 125F. So, what's with these 2.3Ah cells??


----------



## SilverFox

Hello Bill,

That's more like it. I really don't know what is going on with those other cells.

Tom


----------



## TorchBoy

LuxLuthor said:


> Why would they make that happen with the cycles mode down to 0.9 but not on regular discharge?











webfors said:


> FYI: I've seen this phenomena on my first revision of c9000, when cycling 4 batteries and attempting to view the cycle info after2-3 cycles. Haven't seen it on my new revision yet.


I'm always happy to not be the only one. Means I'm not going crazy.



webfors said:


> FYI: Flaws will always be pointed out on new products, especially by tech-geeks like us who gotta know everything there is to know about charging batteries.. lol.


Hey, "tech-nerd" here, thanks.


----------



## TorchBoy

webfors said:


> My biggest pet peeve wasn't the heat at 2amps (which the new version seems to do better as well), it was having to worry about leaving it alone for a few hours with the thought of miss terminations running wild in my head. The new version addressed all my concerns so far. Nothing but good things to say about it.. hope it stays that way :rock:


Yeah, that was a big concern, and the thought that just using it might be damaging the cells. The new one has put those concerns to rest, except for...



wptski said:


> So, what's with these 2.3Ah cells??


They're "crap" cells.


----------



## wptski

TorchBoy said:


> Yeah, that was a big concern, and the thought that just using it might be damaging the cells. The new one has put those concerns to rest, except for...
> 
> 
> They're "crap" cells.


That's "crap"!!


----------



## LuxLuthor

LOL! No, they are "crap cells" he said. That is a new battery classification.


----------



## TorchBoy

Maybe it's a chemistry all of its own. Li-Ion, NiMH, NiCd, and CrAp. :thinking:


----------



## wptski

After a conversation with Tom yesterday in which he asked me what the charger temperature was at 1A and 2A I discovered the following. I PM'd him this info.
>>
Here's something for you to think about!

Duracell 2.3Ah at 1A gets the charger at center hot spot to 137F and at 2A it's 144F. The 2.65Ah Duracells got the charger to 134F at 2A. Sanyo 2.7Ah were 138F. Of course that's a bit less %C on the larger cells but can that account for the difference in charger temperature? 
>>

Something in those cells causes the improved C9000 to generate more heat. It's working harder trying to maintain 2A with those cells. Is it thermal runaway?

I think I'm going to try a small fan to remove the heat from the charger.


----------



## SilverFox

Hello Bill,

I know your impedance meter doesn't do will with the pulses of the C9000, but it would be interesting to see if you can notice anything strange about those cells under a 2 amp charge.

You would have to slow the sample rate down to see if you could get a reading between pulses, but it may be worth a look at...

Tom


----------



## wptski

Tom:

I was thinking about that also. I did post a few from the original C9000 at 1sec and 2sec interval but I'd have to look up what cells I used.


----------



## sylvainp

Here are my observation concerning the improve C9000 model compared to the original model.


- The first thing i found on the improve model the time to select the MODE features has been extended so we have more time before the charger goes in the default charge MODE. A good thing !

- On the old model the REST was 1 hour after a charge cycle. On the improve model it is 2 hours.


- Also found the improve model to make less noise coming from pulse charging tone.

- Also tried a 200 mah charge rate on PowerEx 2700 AA (charge at about 95%) and the charge terminated with about 300 ma of charge current load to the cells.

- Also tried but didn't finish a Cycle Mode and so far i didn't see the 5 5 or 4 4 problem on the display.

- I didn't tried the break-in Mode either which I will do later today on all my new AAA cell.

Sylvain


----------



## SilverFox

Hello Sylvain,

Welcome to CPF.

You almost have it correct. The 2 hour rest period does not happen while using the Break-In mode. You should also understand that the 2 hour rest is only on the charge cycle. At the end of the discharge cycle, the rest is still 1 hour.

Tom


----------



## sylvainp

SilverFox said:


> Hello Sylvain,
> 
> Welcome to CPF.
> 
> You almost have it correct. The 2 hour rest period does not happen while using the Break-In mode. You should also understand that the 2 hour rest is only on the charge cycle. At the end of the discharge cycle, the rest is still 1 hour.
> 
> Tom


 
You are right Tom, I just see it on my charger that on the discharge cycle the rest is 1 hours. Like you said on the charge cycle it is 2 hours.

Why they put 2 hours after a charge cycle ? Could it be possible that because the charger don't charge as fully compared to the old model to prevent heat & overcharge and cut the fast charging mode to switch to a longer top off charge cycle to fully charge the cells ?

Sylvain


----------



## wptski

Tom:

More confusion! I went to graph the impedance while charging, so I have the cell clamped external to the charger. Any time before when I did any testing, I mostly had only one cell connected and the other slots were empty! Well this time, I had cells in the other three slots. Here's the inputs, time and temperature. I'll post the impedance graphs later. I'd like find a way to connect right at the cells while inserted while charging but there isn't much room for anything thick enough to clip to!!

Inputs, time, temperature and discharge mAh at 500ma.

Slot#1= 2102mAh, 71 min, 146.7F, 1884mAh
Slot#2= 2373mAh, 80 min, 155.4F, 2059mAh
Slot#3= 1959mAh, 66 min, 87.4F, 1923mAh
Slot#4= 2191mAh, 74 min, 117.2F, 2045mAh

What a difference just by connecting one cell outside the charger. The hot spot in the charger was 127F. This is really crazy, hey??

Okay, here's the impedance graphs. The one on the left is from an earlier post using the original C9000 and the right is the improved version. I forgot to mention above the same 2.3Ah Duracells were discharged and the rate again was 2A.

What does it all mean though?  Got to find a way to connect while the cell is inserted!!


----------



## SilverFox

Hello Sylvain,

Correct. Maha believes that since the improved charger terminates earlier, to get accurate results from the Refresh and Cycle modes, the cells need to be topped off. The top off charge goes for 2 hours.

Tom


----------



## SilverFox

Hello Bill,

Without the extra heat from the charger, the voltage from that cell must be leveling out early and causing the premature termination.

Tom


----------



## tacoal

SilverFox said:


> Hello Bill,
> 
> Without the extra heat from the charger, the voltage from that cell must be leveling out early and causing the premature termination.
> 
> Tom


 
Hi Tom,

Honestly say, I don't agree with your explanation.

Higher ambient temperature will lead to generate less negative voltage over the time. You could get this info from the document of a battery manufacture like this one Panasonic_NiMH_Overview.pdf, the fugure at the bottom right of page 9.

Bill's result means obviously that the external connection one is terminated properly and other three is overcharged, 121% at most by C9000. This does not take account of the little overcharge for the external connection one.

Another fact is slot 2 has the biggest overcharge due to higher ambient temperature than other slots. This agrees with the result from the document in first paragraph.


----------



## wptski

Tom:

I've charged those cells on the ICE charger at 2.3A, a bit more and they got to, if I remember correctly, 107F. That's a bit too cool, something else is a muck here.

The impedance graphs are bit different also but normally because it's easier to connect to, I'd use Slot#4, so the left hand graph is probably from that slot.


----------



## wptski

tacoal:

It's been said that the improved version doesn't use -DeltaV but a variation of ZeroDeltaV. It still could be that the others are overcharged. If you've been following this 2.3Ah Duracell saga, the original C9000 "seemed" to terminate early on the center two slots, now the improved version, the center two take longer to terminate and have got as high as 159F. The 2.2Ah Energizers don't do that and neither does 2.7Ah Sanyos or 2.65Ah Duracells. The hot spot under the center slots remain cooler with the just mentioned cells also. Very confusing!!


----------



## SilverFox

Hello Tacoal,

You are correct. I was thinking backward.

I was thinking that the timing of the voltage peak would be influenced by temperature. I actually had it backward. At higher temperature, the peak occurs later. 

I believe Bill discharged these cells before charging them, and they are 2300 mAh cells. I am not sure what their actual capacity is at this time, so I can't comment on whether they were over or under charged.

The question still remains, why are only these cells heating up so much? His other cells are ending up in the 120 - 135 F range when charged at 2 amps. What is causing the 20 - 30 F increase in temperature?

I think it has something to do with the cells internal resistance, but the impedance of these cells seems to be similar to other cells that charge a lot cooler.

Tom


----------



## tacoal

Hi Bill,

ZeroDeltaV happens before -DeltaV in time scale. Or if there is a -DeltaV, there must be a ZeroDeltaV happened before it.

My guess is that Maha's original release comes with the algorithm based on thermal and voltage condition of battery and has bug in the implementation. The fixed release seems droped the thermal part.

Could you do another test to charge these cells with a fan blowing at the batteries and charger on the improved C9000? I guess they all will be terminated properly, not like the first release.

Hi Tom,

The temperature increase might be due to sumation of ambient and self heating. It is know the battery will generate more and more heat toward the end of the charging cycle since less energy will be converted to chemical one. This could be considered as the increase of battery impedence, this means the internal resistance increase when battery temperature increasing, not a constant.

A so-called 2300Mah battery might not have that capacity. The confusing thing is
the charging capacity is usually 110% to 120% of battery capacity. If bill's battery are 2300Mah ones, it should be charged to 2530 to 2760Mah, none of them meets this on bill's test data.

If you don't think those batteries in the slot is overcharged, you imply the one with external connection is undercharged. I have no idea how a smart charger can do that since even 0DeltaV will have a little bit overcharge on battery. Maha might have a new way to do that if your guess is right.


----------



## SilverFox

Hello Tacoal,

A couple of odd confusing things...

Impedance usually will go down as temperature rises, but can rise at the end of the charge cycle when the cell goes into the oxygen recombination process. Bill's two impedance graphs seem to show a general rise in overall impedance occurred over a few charge cycles. However the change from around 0.020 ohms to 0.025 ohms does not seem that drastic, and other cells with similar impedance values charge cooler.

Undercharging, or "false peaking," is regularly observed with new cells, and those that have been in extended storage. Usually the "false peak" will occur within the first 10 minutes of the charge, but I have seen it at later stages with damaged cells. Bill will have to do a discharge on them to see what their actual capacity is.

Tom


----------



## dekelsey61

Hi Tom,
I have a question for you. I have some Sanyo 2700Mah AA batteries that the voltage goes down faster than some other batteries. I know open voltage is not the best way to check discharge.
I have the new version of the C9000 charger. What I want to do is to get the batteries capacity and charge them full and let them sit for 1 week and then see how much capacity(Mah) was lost in 1 week of just sitting.
What is the best way on the C9000 charger to do this test?
Thank you very much.
Dan


----------



## wptski

Tom:

Yes, all cells were discharged prior to charging. I'm discharging the 2.3Ah Duracells used in the above test right now at 500ma, close to .2C as one can get manually.

tacoal:

I don't know if you've seen this thread:Impedance Graphs in which I used a Duaratrax ICE to graph various cells. The graph for the 2.3Ah Duracells are unlike the others, very flat all the way through!

I've haven't had hardly any inputs that were over the rated cell's capacity with either the old or new C9000.

I plan on trying PowerEx 2.0Ah and 1.8Ah cells today. I'd like to devise a way to attach my impedance meter right to the cells while inserted but I'm not sure if I'll be able to do so!!

EDIT: Corrected link to the proper graphs!


----------



## SilverFox

Hello Dan,

You can charge the cells up, let them rest, then do a discharge on them. Now you will have a baseline for comparison. Next you charge the cells back up and let them sit for a week. Once again discharge them at the same rate you used before. This will give you the capacity after 1 week of storage.

Tom


----------



## dekelsey61

Thank you Tom.

Dan


----------



## wptski

PowerEx 2Ah cells first discharged and charging at 2A. Inputs, time and temperature.

Slot#1= 2176mAh, 73 min, 143.4F
Slot#2= 2232mAh, 75 min, 155.8F
Slot#3= 2338mAh, 79 min, 160.4F
Slot#4= 2352mAh, 79 min, 143.0F

Charger hot spot was 145F. I somehow thought that these weren't going to get so hot, wrong!!


----------



## SilverFox

Hello Bill,

Hmm... Still too hot.

Tom


----------



## wptski

PowerEx 1.8Ah cells first discharged and charged at 1800ma. Inputs, time and temperatures. Charger hot spot was 143.0F.

Slot#1= 2038mAh, 76 min, 126.4F
Slot#2= 2173mAh, 82 min, 154.0F
Slot#3= 2245mAh, 83 min, 153.4F
Slot#4= 2114mAh, 78 min, 119.4F


----------



## LuxLuthor

I did those same four PowerEx 2200 mAh cells of which two (slots 2 & 3) did not terminate in early version. They terminated fine with this new version charger, and did not get as hot to the touch. I had marked the batteries with a Sharpie, and made sure to put the non-terminating ones back in the same slots 2 & 3. I again discharged them at .9A and charged again at 1.5A


----------



## wptski

LuxLuthor said:


> I did those same four PowerEx 2200 mAh cells of which two (slots 2 & 3) did not terminate in early version. They terminated fine with this new version charger, and did not get as hot to the touch. I had marked the batteries with a Sharpie, and made sure to put the non-terminating ones back in the same slots 2 & 3. I again discharged them at .9A and charged again at 1.5A


Try them at 2A.


----------



## wptski

I edited Post#204 with discharges of the 2.3Ah Duracells. Oh yeah, tacoal was correct about the fact that the externally connected cell with no heat from the charger terminated correct, although low! Slot#2 did have the largest overcharge too!


----------



## tacoal

Hi Tom,

In general, the resistence is a linear one. However, the impedence of a battery might be a nonlinear one. This mean it changes with the current through it. Further, the impedence when changing might be different from the internal resistence when discharging.

Yes, some batteries, the high capacity ones, once stopped on BC-900 when voltage is about 1.4V. I had to pulled it out and put it in to continue the charge.

Bill,

I once checked that post. I searched it roughly and did not find the testing current.


----------



## wptski

tacoal:

Look at the graphs as all are marked with cell brand, capacity and 1C. A few have other notations.


----------



## tacoal

Hi Bill,

I am sorry I missed that info since I presumed there is something like xxxma .....


----------



## wptski

The same 2.3Ah Duracells discharged and charged at 2A with a small fan attached to the bottom of the unit forcing air through the slots near the metal folding stand. Inputs, time, temperature, capacity with a 500ma discharge rate and capacity with a 500ma discharge rate of a 16 hr break-in.

Slot#1= 2106mAh, 71 min, 127.3F, 1969mAh, 2001mAh
Slot#2= 2050mAh, 69 min, 113.2F, 1969mAh, 2249mAh
Slot#3= 2079mAh, 70 min, 113.2F, 2013mAh, 2276mAh
Slot#4= 2050mAh, 68 min, 106.2F, 2018mAh, 2242mAh

The Slot#1 cell has a bit higher impedance, not sure if that accounts for the higher temperature.

EDIT: Added break-in capacity with a 500ma discharge rate. Slot#1 has the higher impedance reading cell.


----------



## coppertrail

Either my DMM is way off, or the C9000 doesn't accurately determine cell voltage. 

I've been storing 4 Powerex 2500 mAh cells in the refrigerator for about 2 months. I let them get to room temp and tested them with my DMM

Voltages were as follows:

1. 1.24V
2. 1.24V
3. 1.28V
4. 1.28V

When I put them in this order in slots 1-4 on the C900 for a discharge cycle, the voltages displayed as follows:

1. 1.17V
2. 1.17V
3. 1.15V
4. 1.15V

Something seems way off here unless I'm missing something?


----------



## wptski

Chris:

Yes, I noticed a difference too but I don't remember which way it was and it was on the original version also.


----------



## SilverFox

Hello Chris,

I believe the C9000 displays the voltage under the discharge load.

Tom


----------



## verge

SilverFox said:


> Hello Bmoorehouse,
> 
> It appears that we have lost the capability to externally charge C and D cells because the time limit has been reduced from 20000 mAh down to 4000 mAh. However, you can still select 20000 mAh as the capacity of a cell in the Break In mode. This means that you should be able to do a forming charge on large capacity cells, but when charging them, you would have to restart the charge a few times.



SilverFox, how does one get to set the charging rate higher than 2000 MAH on the CHARGE mode? I intend to buy rechargeable C and D batteries.

BREAK-IN mode goes up to 20.00 Ah, but I can only set the charging rate of my MH-C9000 *(0FAB02)* on CHARGE mode to a max of 2000 MAH.

Should CHARGE mode of the old model *(0FAB02)* be able to set current from 200 MAH up to 20.00 Ah?


----------



## coppertrail

Tom - Thank you, I was starting to see that it's not measuring the exact voltage of the cell as it was remaining pretty steady throughout the duration of the discharge cycle.


----------



## sylvainp

verge said:


> SilverFox, how does one get to set the charging rate higher than 2000 MAH on the CHARGE mode? I intend to buy rechargeable C and D batteries.
> 
> BREAK-IN mode goes up to 20.00 Ah, but I can only set the charging rate of my MH-C9000 *(0FAB02)* on CHARGE mode to a max of 2000 MAH.
> 
> Should CHARGE mode of the old model *(0FAB02)* be able to set current from 200 MAH up to 20.00 Ah?


 
First on the BREAK-IN MODE you are entering the battery capacity so the charger will choose a charge rate of 0.1C and a discharge rate of 0.2C for this battery capacity.

EX: If you enter 2500 mah
It will charge at 250 mah (0.1C of 2500 mah)
And discharge at 500 mah (0.2C of 2500 mah)

The charger is only capable of charging rate between 200 to 2000 mah.

Hope this help !


----------



## SilverFox

Hello Verge,

First we need to define some terminology...

mAh refers to capacity. mA refers to current.

The maximum charging rate for the C9000 is 2000 mA. This applies to all versions.

The C9000 has a timer that limits the charge. The original timer was set to terminate at 20000 mAh of charge. If you were charging at 2000 mA, the timer would shut things off at 10 hours. If you were charging at 1000 mA, the timer would shut off at 20 hours, and so on.

The improved C9000 has that timer reduced from 20000 mAh to 4000 mAh. Now, if you are charging at 2000 mA, the timer will shut things down after 2 hours.

The Break-In mode on the C9000 involves charging at 0.1C for 16 hours. Since the maximum charge rate of the C9000 is 2000 mA, the maximum battery capacity you can have and still charge at a 0.1C rate is 20000 mAh.

Tom


----------



## Bones

Greetings from another new member who is very appreciative of the tremendous amount of hard won knowledge so generously shared in this forum.

It appears evident that the C9000 benefits from forced venting, so I thought I would solicit some input on a semi-permanent modification.

There's enough room inside the charger (in the upper right corner) to mount a small fan, such as those used to vent video cards.

What I am wondering is whether the fan could be powered from the charger itself, and if so, whether it would be okay to solder the fan leads to the power points on the bottom of the circuit board under the dc in connection?

The typical specifications of the fans I have found so far are 12volt dc, .08 amps and .09 watts.

If this modification works, I will, of course, share all the details.


----------



## coppertrail

Although not powered from the charger, this is what I rigged up: (Thanks dekelsey!)


----------



## verge

SilverFox, thanks for clearing my confused mind.

Powerex 11,000 mAH D battery x 0.1C (1100 mA) = 10 hrs.
Powerex 11,000 mAH D battery x 0.2C (2200 mA) = 5 hrs.

The 4000 MAH limit is not even half of the Powerex D 11,000 mAH battery's rated capacity.

I can use only the BREAK-IN mode to charge C and D cells. I mistakenly presumed that the new C9000 model's losing the capability to charge C and D cells pertains to a MAH setting in the CHARGE mode of my charger. 

Thanks again for the response.


----------



## dekelsey61

This picture of the fan on top of the C9000 charger that coppertrail is showing works great!!! It pulls the hot air out of the charger that way your batteries stay really cool!! I have charged some batteries at a very high rate at at the end of the charge the batteries are barely 100F with the fan on top of the charger. NO HEAT ISSUES ANYMORE!!
Dan




coppertrail said:


> Although not powered from the charger, this is what I rigged up: (Thanks dekelsey!)


----------



## SilverFox

Hello Verge,

You are almost correct...

You can use the 2000 mA rate to charge your 11000 mAh cells, however they will time out after 4000 mAh. When this happens you just start the charge again. 

If they are completely drained, you would put them in your external cell holder and start the charge at 2000 mA. 2 hours later, you would have to restart the charge again, and 2 hours after that, you would do it one more time. Charge time would be a little over 6 hours.

If they aren't completely drained, it would go faster.

Tom


----------



## Bones

Thank you for your replies coppertail and dekelsey61.

It was actually your posts confirming that the concept works great that got me thinking about an internally mounted fan.

If it turns out that that a fan can't be powered from the charger, I will certainly be following your lead with an external fan.

However, I would still like to try an internal mount first, if for no other reason than just to see if it can be done.

Hopefully, I won't end up frying the charger...


----------



## wptski

coppertrail said:


> Tom - Thank you, I was starting to see that it's not measuring the exact voltage of the cell as it was remaining pretty steady throughout the duration of the discharge cycle.


What, it doesn't decrease throughout the cycle????


----------



## coppertrail

It does decrease, but not at a rate that I can say that it's reporting the actual voltages of the cells during discharge.


----------



## wptski

Dan:

You shouldn't have heat issues to begin with! I used a fan on the these 2.3Ah Duracells charging for the first time "ever" on "any" charger just to prove a point! So far, I can charge some cells at 2A without them getting too and other brands I can't. I'll only be using 2A when I can, otherwise .5C.


----------



## wptski

coppertrail said:


> It does decrease, but not at a rate that I can say that it's reporting the actual voltages of the cells during discharge.


What else could it be reporting if not cell voltage that means anything to the user?


----------



## LuxLuthor

wptski said:


> Try them at 2A.



What should I be watching? Heat issues? Unfortunately I can only compare my finger touch method as compared to the 1500 mA charging which gives a ballpark difference, but it seems that your tests have already proven with 1.8 & 2.0 mAh PowerEx that slots 2 & 3 are an issue @ 2A rates...I guess I will just assume I should use 1.5A on my PowerEx.

One thing I could try is putting them in one of those 4 AA cell black TD battery holders and charging it at 2A on my Hyperion, and see how hot it gets...but I seem to remember someone saying those holder springs have too much resistance to be useful at high C rates? ?


----------



## verge

SilverFox said:


> Hello Verge,
> 
> You are almost correct...
> 
> You can use the 2000 mA rate to charge your 11000 mAh cells, however they will time out after 4000 mAh. When this happens you just start the charge again.
> 
> If they are completely drained, you would put them in your external cell holder and start the charge at 2000 mA. 2 hours later, you would have to restart the charge again, and 2 hours after that, you would do it one more time. Charge time would be a little over 6 hours.
> 
> If they aren't completely drained, it would go faster.
> 
> Tom



Now I'm a little confused again. I'll be using the old version C9000 *(0FAB02)*. 

Can't I just set the CHARGE rate to 2000 mA and let it run until the display shows 11,000 or 12,000 MAH at about 5.5 to 6 hours later? I shouldn't have to charge and restart because the C9000 *(0FAB02)* limit is up to 20,000 MAH.

Thanks for responding.


----------



## wptski

LuxLuthor said:


> What should I be watching? Heat issues? Unfortunately I can only compare my finger touch method as compared to the 1500 mA charging which gives a ballpark difference, but it seems that your tests have already proven with 1.8 & 2.0 mAh PowerEx that slots 2 & 3 are an issue @ 2A rates...I guess I will just assume I should use 1.5A on my PowerEx.
> 
> One thing I could try is putting them in one of those 4 AA cell black TD battery holders and charging it at 2A on my Hyperion, and see how hot it gets...but I seem to remember someone saying those holder springs have too much resistance to be useful at high C rates? ?


I just wonder if PowerEx 2.2Ah cells will heat up, finish later than the other slots, etc? Compared to charging at 1.5A. It "apears" that the different chemistries used act differently while charging. I wonder if the 2.2Ah might be different than the 1.8/2.0Ah cells?

If they get above 150F, you won't be able to hold on to them very long!


----------



## SilverFox

Hello Verge,

Oops, can I claim a senior moment...? 

Tom


----------



## verge

^ compared to the tons of usefull information you have shared here, that's hardly a speck of fault or weakness.


----------



## TorchBoy

verge said:


> Now I'm a little confused again. I'll be using the old version C9000 *(0FAB02)*.


Now I'm a little confused. You know this thread is about the new version?  

On which subject, I've got another pic to add to the collection. 3 3, 4 4, and 5 5. :huh2:


----------



## wptski

Tom:

Just for comparison. If I was to take cells that didn't heat up at 2A on the C9000, ones that did and charged at 2A while monitoring temperature on a Duratrax ICE, what would that prove? If the cells have a strange problem, you'd think that it would show up on other chargers too? I was think of trying the BC-900 but it's going to pause at around 130F. Another one is the MAHA 401FS, I think that's the model number. It's the one that does two in series and is a known cooker!!


----------



## SilverFox

Hello Bill,

If you took cells that did not heat up on the C9000, and monitored their temperature when charging on the ICE, then charged your Duracell 2300 mAh cells on the ICE, you would have a comparison.

The ICE does not have to deal with the temperature of the charger, so I would expect the Duracell cells to end up cooler, but they still should be hotter than the other cells that don't heat up on the C9000.

Tom


----------



## SilverFox

Hello Ian,

I still have not been able to document the "missing digit feature" on my C9000. Could you take me through it step by step?

I did run across it with the original unit, but forgot how to get it to show up.

Tom


----------



## wptski

Tom:

I'll have to try that next. There's always something to try yet!


----------



## wptski

Edited Post#226. Still a bit odd even with cooling fan but maybe I didn't come up with the best way to do it.


----------



## TorchBoy

Tom:

Insert an AAA cell into slot 1. Select CYCLE for 2 or more cycles (I tested it with 2 and 3). The charge and discharge rates appear to only affect the resulting capacity, so select whatever you want, and just wait until the first cycle has finished.

In other news, last night I was doing a _Refresh Analyse_ on some AA Eneloop cells and found the cell in slot 1 discharging at a very steady 1176mA. I was a bit annoyed/surprised because I had selected 1000mA and normally it's pretty close, almost always within 4% of the selected rate, not pushing _18%_. I didn't even think until later that 1000mA is supposed to be the upper limit for discharge. The end result was 2002mAh. I'll try to reproduce.

_Edit: Yes, slot 1 discharges faster than the other slots. It's not cell dependent and does appear to integrate correctly. Observed in Refresh Analyse and Discharge modes. Slot 1 is now 1161mA and slowly rising, while the others are within 4mA (ie, 0.4%) of the selected 1000mA rate._


----------



## TorchBoy

Highest I saw was 1181mA. Other slots were within 1-2% of the nominal figure.






Just when I was beginning to think I could rely on it for accurate analysis. :scowl:


----------



## wptski

Tom:

I took one of the problem Duracell 2.3Ah cells and a non-problem Energizer 2.2Ah cell. Both discharged cells on the ICE charger at 2A with a contact type probe logging temperatures. The Energizer got to 93F and the Duracell got to only 99.1F.

No huge difference in temperature at all! The problem with the Duracells must be triggered at/above a certain temperature generated by the C9000 because it sure didn't do it on the ICE. That's a long way from darn near 160F.


----------



## tacoal

Hi Bill,

Thanks for the test.

Comparing the results without a fan, temperature is low, charging capacity is reduced while the discharging capacity almost unchanged and terminated properly without the problem of 'hesitate to terminate with a fan'. 

I don't know how tha fan is positioned. Since the result is not as good as that of the external connected cell, I think the fan might not blow the flow to batteries directly. Correct me if I am wrong.

The result confirmed my guess that on the 'improved' C9000, Maha dropped the algorithm of termination based on thermal condition of battery, which caused overcharging battery.


----------



## wptski

tacoal:

The fan wasn't blowing on the cells at all but air was forced inside the charger from center slots on the bottom. The one cell that still got warm compared to others was the "same" cell that got rather warm compared to others on the C80M too!

If you refering to thermal termination, I don't think that it was ever used on the C9000. The thermal backup of around 131F at the negative end of the cell has never shut down the charger even when a cell reached almost 160F at the positive end. The negative end is cooler but the area around the metal sensor contact lags the cell by 15F.

The thing that confuses me is that if the original unit used -DeltaV and this one uses a variation of ZeroDeltaV it should be undercharging compared to the original. This should charge with less heat generated and it's not! Or at least, it isn't with these Duracells as they get even hotter than before.

I may fiddle around with graphing temperature at different charging rates to see if I can find the point at which these cell begin to generate lots of heat.


----------



## TorchBoy

Using the 900mA discharge setting, I had a slow and steady rise over a few minutes from what the current should have been, to 988mA.






However, at 100mA it seems OK, being about the 100mA it should be. It's not cell dependant - I've tried a couple with similar results - and it's just slot 1 it happens with. My theory is a key component (or connection to that component) for slot 1 is overheating with the current, causing the current to slowly increase until the component reaches thermal equilibrium. 

The capacity integration still seems to work OK, which is good.

If my theory about component heating is correct I don't expect anyone else will see this (unless perchance they have the same dodgy component). The missing digit problem, on the other hand (eg, 5 5) appears to be in firmware, since I've seen it in both versions, so I'd be surprised if anyone didn't see that if they went looking for it. Found it, Tom?

Edit: To test my heat idea I tried blowing into the charger just above slot 1 for about a minute. The discharge current dropped a whole 30mA from 987mA to 957mA. It took just a couple of minutes to climb back to 984mA and is holding steady there. Can I feel smug about my deductive ability? :rock:

Edit 2: FWIW the highest discharge rate seen at nominal 500mA setting was 524mA. Fits the profile - less heat, less overshoot.


----------



## SilverFox

Hello Bill,

I have a battery pack for my phone that is ready for retirement. I decided to plot the Schulze charging graph for it.







What do you think triggered the end of charge termination?

These cells get hot during a 1C charge, but present a normal charge graph and remain cool during a 0.5C charge. I wonder if your Duracell 2300 mAh cells are doing something similar?

At any rate, it is an interesting graph. I have not seen one like this before...

Tom


----------



## tacoal

wptski said:


> tacoal:
> 
> The fan wasn't blowing on the cells at all but air was forced inside the charger from center slots on the bottom. The one cell that still got warm compared to others was the "same" cell that got rather warm compared to others on the C80M too!
> 
> If you refering to thermal termination, I don't think that it was ever used on the C9000. The thermal backup of around 131F at the negative end of the cell has never shut down the charger even when a cell reached almost 160F at the positive end. The negative end is cooler but the area around the metal sensor contact lags the cell by 15F.
> 
> The thing that confuses me is that if the original unit used -DeltaV and this one uses a variation of ZeroDeltaV it should be undercharging compared to the original. This should charge with less heat generated and it's not! Or at least, it isn't with these Duracells as they get even hotter than before.
> 
> I may fiddle around with graphing temperature at different charging rates to see if I can find the point at which these cell begin to generate lots of heat.


 
If you position the fan to blow air to the batteries directly, you will get 
cooler batteries. It should be better than the external connected one. The 
charger still warmed up the battery in your test.
If you say the thermal condition of battery is not used in OLD C9000, I don't 
think you have a reasonable explanation for MH-C9000 hesitates to cut off with 
cooling fan ?! Your test shows that the fan is very helpful for the charger to 
do the termination properly.
I think Maha did something wrong in combining the voltage and thermal condition 
to decide the termination, possibly the AND logic is simply used so the 
termination needs both voltage to have decrease and the temperature to have a 
slope. This could explain why a fan would make the charger terminate worse.
Panasonic did the similar stuff on their BQ-830 and failed. The aftermath is the 
recall of all BQ-830.


----------



## TorchBoy

SilverFox said:


> What do you think triggered the end of charge termination?


Zero delta V. (Does the Schulze have that?) It's a three cell pack, right?


----------



## SilverFox

Hello Ian,

Zero delta V occurred about 2 minutes into the charge...

Edit: I was referring to the loaded voltage. You are looking at the unloaded voltage, but I am not sure that is what the Schulze looks at. At any rate, for the last 11 minutes, the unloaded voltage is the same. Peak voltage detect is usually quicker than that, but who knows.

I believe the Schulze terminates on a -dV of around 3 mV for NiMh and 10 mV for NiCd. These are NiCd cells. EndEDIT:

Tom


----------



## sajmmiller

TorchBoy said:


> Using the 900mA discharge setting, I had a slow and steady rise over a few minutes from what the current should have been, to 988mA.
> 
> 
> 
> 
> 
> 
> If my theory about component heating is correct I don't expect anyone else will see this (unless perchance they have the same dodgy component).



I saw this problem with my first C9000, but it was with slot 2 or 3, I don't remember which. The problem slot discharged at a rate about 15% higher than the set rate.

Scott


----------



## wptski

tacoal:

There's a thermal condition but it's not anything in the charger, I think that it's a thermal condition in the battery sparked by the charger's heating.

What cells in Post#226 do you think terminated properly? All but Slot#1?


----------



## TorchBoy

sajmmiller said:


> I saw this problem with my first C9000, but it was with slot 2 or 3, I don't remember which. The problem slot discharged at a rate about 15% higher than the set rate.
> 
> Scott


Interesting, Scott. Have you seen it with your subsequent C9000(s)?

Tom, have you managed to reproduce the missing/repeated digit problem?

As for the NiCd pack charging graph, I'd guess the loaded voltage decrease would be because of or to create a drop in charging current.


----------



## wptski

Tom:

That's odd, a decreasing voltage!


----------



## tacoal

wptski said:


> tacoal:
> 
> There's a thermal condition but it's not anything in the charger, I think that it's a thermal condition in the battery sparked by the charger's heating.
> 
> What cells in Post#226 do you think terminated properly? All but Slot#1?


 
All the cell are terminated properly. keep in mind that each cell has her personality. The cell in slot 1 has a little bit crap.

The manufacture suggested using thermal slope (dT/dt) as a criteria to terminate the changing, Maha implemented its algorithm in old C9000. However, an added cooling fan will try to keep the temperature unchanged (or less slope), cause the old C9000 hard to get enough thermal slope to terminate the charging.

If the old C9000 did not include the thermal condition of the battery, a cooling fan won't affect the termination of charging. If it use -DeltaV or 0DeltaV, a cooling fan will be helpful to terminate the charging properly, this is the case of 'improved' C9000.


----------



## SilverFox

Hello Ian,

I have some other projects tying up the C9000 right now, but will check it out later.

The battery pack was charged at a constant 1 amp. I believe the drop in loaded voltage has to do with the internal resistance of the cells. They are at over 0.200 ohms per cell.

Tom


----------



## TorchBoy

SilverFox said:


> The battery pack was charged at a constant 1 amp. I believe the drop in loaded voltage has to do with the internal resistance of the cells. They are at over 0.200 ohms per cell.
> 
> Tom


Constant current charging and V=IR tells me that the resistance of the cells must then have dropped a bit as they were charged. Um... Is that normal? You mentioned you hadn't seen a graph like it, but hot cells do have a lower internal resistance don't they?


----------



## SilverFox

Hello Ian,

I agree. As the cells heat up, their internal resistance drops, but I was not expecting the loaded voltage to also drop.

Usually, with high internal resistance cells, you will see a wide spread between loaded and unloaded voltage, that will narrow down as the cells heat up. However, usually both loaded and unloaded voltage rise until near the end of the charge.

Tom


----------



## wptski

tacoal said:


> All the cell are terminated properly. keep in mind that each cell has her personality. The cell in slot 1 has a little bit crap.
> 
> The manufacture suggested using thermal slope (dT/dt) as a criteria to terminate the changing, Maha implemented its algorithm in old C9000. However, an added cooling fan will try to keep the temperature unchanged (or less slope), cause the old C9000 hard to get enough thermal slope to terminate the charging.
> 
> If the old C9000 did not include the thermal condition of the battery, a cooling fan won't affect the termination of charging. If it use -DeltaV or 0DeltaV, a cooling fan will be helpful to terminate the charging properly, this is the case of 'improved' C9000.


tacoal:
The use of dT/dt was something that was mentioned in the pre-sales description at T/D but there's "no" mention of this at MAHA's site! This has been hashed/bashed over and over again, it was/isn't used. I'm not really sure if there's any truth to the fact that a fan affected termination, to many variables! IMHO


----------



## sajmmiller

TorchBoy said:


> Interesting, Scott. Have you seen it with your subsequent C9000(s)?



Ian,

No, my second C9000 (Still not the improved version) did not have that problem. All slots discharged very close to the set rate.

Scott


----------



## wptski

Took a single 2.3Ah Duracell, cells I'm having a problem with and a single 2.2Ah Energizer cell that gives me no problems. Inserted the cell(s) into Slot#2, charging at 2A and graphed the temperature on a scope, something I could leave unattended! Input capacity, time and temperature.

Duracell= 1969mAh, 63 min, 98.7F
Energizer= 2250mAh, 75 min, 99.5F

This is odd as I expected the Duracell to get warmer since they got very hot while charging four cells and the Energizers didn't!


----------



## tacoal

wptski said:


> tacoal:
> The use of dT/dt was something that was mentioned in the pre-sales description at T/D but there's "no" mention of this at MAHA's site! This has been hashed/bashed over and over again, it was/isn't used. I'm not really sure if there's any truth to the fact that a fan affected termination, to many variables! IMHO


Hi Bill,

I got these gueses from the fact of the posts in this BBS, not from T/D or Maha. I just wondered why the 'old' C9000 fails so much on termination while the 'improved' one works fine.

It seems you doubt the truthfulness of the link I mentioned. Are you doubt the result from your test that a fan is helpful for termination for 'improved' C9000? I don't know if you still keep an old C9000. If you have, you could do the test yourself to verify tha fan makes the charger more difficult to terminate the charging or the other way.


----------



## wptski

tacoal:

Not sure "exactly" why the original version missed but -DeltaV on higher capacity at lower charging rates "can" cause that.

My two originals have been shipped back so I can try the fan trick but charging at default setting of 1A resulted in much cooler 2.3Ah Duracells.

A added note for the above single cell test above. I haven't downloaded the graph into my PC yet but I don't see any dT/dt but there was in the single cell test on the ICE charger. Both are around the same temperature too! I know that a charging rate of atleast 1C should be used for a measurable dT/dt but why the difference between the two? Pulse vs constant current?? Tom mentioned reading somewhere that pulsed current shouldn't be used on Ni-MH cells but no reason was given.

EDIT: Just wondering. Since heat is such a factor and the amount of cells inserted affects the amount of heat generated, is termination affected by the number of cells inserted??


----------



## tacoal

Hi Bill,



> but why the difference between the two? Pulse vs constant current?? Tom mentioned reading somewhere that pulsed current shouldn't be used on Ni-MH cells but no reason was given.


 
Tha maximum current in pulse charge is higher. In BC-900, even the charge rate is 200ma, the maximum current is about 2.5A. This might be a reason.



> EDIT: Just wondering. Since heat is such a factor and the amount of cells inserted affects the amount of heat generated, is termination affected by the number of cells inserted??


I don't think they are linked directly, but indirectly. The more batteries charged, the more heat generated by the circuit, esp. the buck converter. These extra heat warms up the battery to make it hard to have a enough -DeltaV so as a significant 0DeltaV.


----------



## wptski

tacoal said:


> Hi Bill,
> 
> 
> 
> Tha maximum current in pulse charge is higher. In BC-900, even the charge rate is 200ma, the maximum current is about 2.5A. This might be a reason.
> 
> 
> I don't think they are linked directly, but indirectly. The more batteries charged, the more heat generated by the circuit, esp. the buck converter. These extra heat warms up the battery to make it hard to have a enough -DeltaV so as a significant 0DeltaV.


tacoal:

I thought that they have meant pulsing in general.

Those same cell acted one way when charged on the ICE with constant current, another way charged with only cell and another way with all four cellsinserted! I'm getting confused.  Too much information!!


----------



## TorchBoy

I've just put another cell through the Cycle mode and the results for the first lap (viewed by pressing the arrow keys after the next charge phase begins - did I mention that?) came out as 1111 mAh, which is not the same as the figure displayed during the post-discharge rest.

I think from memory it was actually just a little under 1200 mAh, so it looks like it's repeating the first two digits. Thus 11XX became 1111, and the previous results, _5XX became _5_5, _4XX became _4_4, _3XX became _3_3.

Perhaps the firmware has a bad copy command, where the first result for that slot is copied into memory.

Update: Done another couple of runs, the 1272 reported in the rest turned into 1212 mAh in the cycle history, and 1321 reported in the rest turned into 1313 mAh in the cycle history. I don't think the old version used to report the capacity during the rest, it just showed 0.


----------



## wptski

This may not be anything with the C9000 itself but with cells in general, although it did happen with the C9000.

I discharged four cells, used the break in mode but pulled them after 16 hours and started to discharge them at slightly over .2C. I happened to be watching it cycle through the slots when I noticed that two slots were around 1.28V but another was at 1.16V and the last was at 1.19V! I've got into the habit of rotating the cells in all my chargers a bit after inserting them.

I rotated the two with the lower voltage a bit more and both increased to the same value as the others. After twenty minutes, they are all about the same.

Maybe some contact cleaner is in order here, hey? I wonder how this would have affected the outcome? I wonder how times something like this gave a skewed value?


----------



## TorchBoy

I've noticed some really weird results recently as well. I did some cycles with a single cell in slot 4 yesterday and got results for all cycles only about 1/10 what they should have been, and they were getting worse. I thought the cell had suddenly died on me, but it seems to be working fine now, even in slot 4.

More of a worry, though, was early this morning when I was reviewing the early cycle results for the next lot of cycling (different slot). I pushed the slot button to get the normal display back again and the MH-C9000 reset and went through its startup sequence. All results lost. No reason evident, the power cord was firmly plugged in.

And I still haven't had any comment from Maha about the firmware repeating digits display problem or the too-high discharge current for slot 1.


----------



## wptski

TorchBoy:

Sounds like you have a defective C9000 to me! :mecry:


----------



## TorchBoy

Actually Bill, it seems to be a stream of defective C9000s. The first died with the recurring startup fault (and I found it also once said it was charging an empty slot 2), the second was replaced because (being the first firmware version) it didn't terminate well and had the cycle result write error (ie, repeats the first two digits of the capacity) and the third has the problems mentioned above (post 282), although slot 4 has behaved itself since. Maybe it was just the cell not seated well.

I still think it's the greatest charger/analyser a hobbyist could want but the ones I've had just don't work right.

Still no reply from Maha. Maybe they're tired of me, maybe they're trying to fix the firmware before offering to send me another. Anyone seen William C online here recently?


----------



## wptski

TorchBoy:

This a very sensitive/touchy charger! My 2.3Ah Duracells that I've posted about several times has took another strange twist.

I'll post some graphs some other day but I took the same cells which I posted temperature graphs using the original C9000 at 2A. The cells get hotter but the slope of the graphs are very different. If the charge rate is the same you'd think that the graphs should remain unchanged except for the maximum temperature. How do cells get hotter when the improved version isn't supposed to be using -DeltaV but a variation of ZeroDeltaV or Peak Voltage? I know that there is a cell issue here too but still this doesn't make any sense at al!


----------



## tacoal

TorchBoy said:


> I've noticed some really weird results recently as well. I did some cycles with a single cell in slot 4 yesterday and got results for all cycles only about 1/10 what they should have been, and they were getting worse. I thought the cell had suddenly died on me, but it seems to be working fine now, even in slot 4.
> 
> More of a worry, though, was early this morning when I was reviewing the early cycle results for the next lot of cycling (different slot). I pushed the slot button to get the normal display back again and the MH-C9000 reset and went through its startup sequence. All results lost. No reason evident, the power cord was firmly plugged in.
> 
> And I still haven't had any comment from Maha about the firmware repeating digits display problem or the too-high discharge current for slot 1.


 
I think this is a typical program bug called program run away. Maha didn't do the good QC/QA on this product, possibly by the tight schedule (or out sourcing?)


----------



## TorchBoy

Tacoal, what issue/problem are you referring to when you mention program run away? The high discharge current I figure is a component for that slot overheating.

Bill, my general impression (without any measurements to back it up) is that on my previous GP 2 hour charger my AAA cells got very warm at the end of their charge. With the first firmware my MH-C9000 on a 1 or 2 hour charge got them hot or very hot for much of the charge, while the latest firmware gets them hot only towards the end, as I'd expect. The nominal charge rates are all about the same, but heat management seems to have been improved. I don't understand it.

I tried rotating an AA cell in the middle of a charge while cycling and it somehow broke the connection, all results lost.


----------



## tacoal

TorchBoy said:


> Tacoal, what issue/problem are you referring to when you mention program run away? The high discharge current I figure is a component for that slot overheating.


 
The cases of reset and the duplicated last 2 digit.

The reset is the worst case that the program controling the charger runs away, the same as in PC when some program behaved strange, causing blue screen and reboot.

The duplicated last 2 digits is a case that the program shows wrong data (the same area in first two digits), the memory for last 2 digits is changed. The pushing key causes these happen.


----------



## LuxLuthor

sylvainp said:
 

> what you guys are using to record the heat generated by the battery ?
> 
> Infrared heat sensors ?



I'm waiting on this $150 infrared thermometer, should be here tomorrow.


----------



## wptski

TorchBoy:

I'm in the mist of graphing/logging my 2.3Ah Duracells at different charging rates and then discharging them at .5A or just over .2C. The results are interesting but also confusing too. 

I wouldn't say that there's anything different with heat management in the improved version as my cells are getting hotter. That is odd since the changes made in the termination method "should" result in cooler cells!


----------



## LuxLuthor

LuxLuthor said:


> I'm waiting on this $150 infrared thermometer, should be here tomorrow.



Well this won't be as colorful and accurate as wptski's great infrared color imager, but this is one slick device. Gives 83.5F temp on my arm, and 96.5F in my armpit. My freezer gives temp of -4.3F. 

Now I'll see what I get in the various slots.


----------



## wptski

LuxLuthor:

Nice tool too!  I "just" found out today which is "way" too late that there was a promo rebate on the Ti30! I could have got a Fluke 87-V DMM for nothing!  Although I already have one, this one was free. :mecry:

I probably got a email on the promo over month before my purchase which was delivered two days before the promo expired but had to be post marked by 1/31/07.


----------



## LuxLuthor

wptski said:


> LuxLuthor:
> 
> Nice tool too!  I "just" found out today which is "way" too late that there was a promo rebate on the Ti30! I could have got a Fluke 87-V DMM for nothing!  Although I already have one, this one was free. :mecry:
> 
> I probably got a email on the promo over month before my purchase which was delivered two days before the promo expired but had to be post marked by 1/31/07.



Oh that would have been sweet !!! I would have bought your old one. I'm discharging the PowerEx 2200's, will rest them for an hour, then crank them up with 2A and check temps !


----------



## LuxLuthor

I finished my 2A charge of the PowerEx 2200 mAh after discharging them in the new version C9000, and waiting an hour. I used that IR Thermal probe which was pretty easy to get precisely on each battery. I have readings of mAh, V, & Temps about every 10 mins, but the summary is:

1) The bottom (-) end of all 4 batteries was much cooler than the top (+) end...with a gradation increase along the length. During much of the charging the top black plastic area above batteries with heat vents was 115°-122°F. Room temp was 68°F

2) All terminated between 46 - 56 mins in this order between 1.44 - 1.46V*46 Mins --- 56 Mins --- 49 Mins --- 47 Mins*​3) Peak temps were reached between 45mins ==> termination time with variation in battery temps from bottom (-) to top (+) as follows:*Top (+) ------ 109°F ------ 118°F ----- 116°F ----- 102°F*
*Bottom (-) ---- 88°F ------ 89°F ------- 86°F ------ 74°F

*​I made sure to take a number of readings to make sure it was consistent each time....this gun type probe makes it very easy. Even if it is not as accurate as a touching contact temp probe might be, the same technique was used for all battery slots, so it does show about a 8-10°F increase temp for slots 2 & 3, while slot 4 was 7-10° cooler than slot 1.


----------



## wptski

LuxLuthor:

Look at this old Post of some temperature graphs with a IR image at the end. I can pinpoint very close with the cursor but your IR temperature has a certain size spot. Isn't it 1" at 12"? I think that your overlapping the cells as your temperature spread from end to end is much too great. I'm not sure if you can get closer than 12" with your probe. I have one which has a 8:1 ratio and your not supposed to get closer than 8" with it. The first one I ever purchased was the one listed below.

If you can find one of these Probe which has a very small spot area.

I just tried my Fluke 65, 8:1 ratio on some discharging cells in the C9000 and it couldn't pick up the higher temperature of the charger itself between the center slots as it averges out the 1" spot area. I dug up my Fluke 80T-IR hyperlinked above and it was able to pick up the higher charger temperature and minor end to end differences in cell temperatures.


----------



## LuxLuthor

Bill, no question that it is not as accurate as your thermal images, but I was doing it from about 8-10 inches which was not significantly different than 12 inches, and it was able to get a drop off between the cells, so it was picking up some of that empty space between the cells.

I thought it seemed low, but after I took the readings I got a pretty good correlation with touching the cells. They were not at all getting too hot to touch like the previous version, and there was a clear difference palpable between the 2, 3 battery slots, and the much cooler 4th slot.

I'm almost embarassed to say this, but because I couldn't believe the variatiion from (-) to (+) ends, I actally touched my lip carefully to the bottom and top ends of the battery (no tongue action though LOL), because it is so much more sensitive than my fingers, and there was a noticeable difference that coincided with the IR Termometer.

Totally different lower temps with these same cells than the previous firmware model.


----------



## wptski

With type of IR probe with a 8:1 or 12:1 ratio the spot doesn't get smaller when held closer than your 12" or my 8". That post I linked to was from the original version.

Which slots terminate first on your C9000?


----------



## LuxLuthor

OK, good to know that my readings were averages of a 1" spot then. I did keep the laser spot on the center of the cell...but that's the best this can do.

They terminated in this order by slot from slot 1=46 min slot 4=47 mins

*46 Mins --- 56 Mins --- 49 Mins --- 47 Mins*​


----------



## wptski

LuxLuthor:

The point that I was trying to make was that there isn't a 29F spread from end to end as your post above shows because the size of the spot. I actually never used an IR probe on the C9000 till today but have used on a cell connected externally. I have on the C808M since it has large spacing between slots. I've always wondered about posts where IR probes were used. I believe SilverFox(Tom) uses a Fluke 80T-IR probe.

Do all your different brands/capacities follow the same temperature and termination sequence too? Probably too early to tell, right? Mine don't! These 2.3Ah Duracells are very strange.

I don't think that you wan't to do your lip test on a 145F cell!


----------



## LuxLuthor

wptski said:


> LuxLuthor:
> 
> The point that I was trying to make was that there isn't a 29F spread from end to end as your post above shows because the size of the spot. I actually never used an IR probe on the C9000 till today but have used on a cell connected externally. I have on the C808M since it has large spacing between slots. I've always wondered about posts where IR probes were used. I believe SilverFox(Tom) uses a Fluke 80T-IR probe.
> 
> Do all your different brands/capacities follow the same temperature and termination sequence too? Probably too early to tell, right? Mine don't! These 2.3Ah Duracells are very strange.
> 
> I don't think that you wan't to do your lip test on a 145F cell!



Yeah, I understand all of your points, and the limitations of this IR method. I regard it as more accurate than my previous "finger" test...but I did make sure the finger test on these cells was not that hot to touch, before going to my more deluxe lip testing! LOL!

There was no question there was a notable difference from bottom to top (+) terminal on my lip on all cells....no idea how much like you say. I didn't think to test it on my old unit, but I do remember these same PowerEx 2200 mAh's were very hot...like only could touch with fingers for a couple seconds.

Ha ha...I looked around to see that no one in the house was seeing me stick my lip on the battery, and sliding up and down...I'm sure it looked funny.


----------



## BVH

Hey Lux, this forum is PG rated. Let's keep it clean... :nana: Sorry, couldn't resist! But you probably expected someone to capitalize on your post, didn't you?


----------



## wptski

LuxLuthor:

On the orginal C9000, these 2.3Ah Duracells finished first in the center slots were cooler compared to the improved C9000 in which the center slots finish last and are much hotter. Not all other brands and capacities act like this though! 

The end to end temperature difference is the same between the original and improved version.


----------



## Power Me Up

wptski said:


> tacoal:
> 
> It's been said that the improved version doesn't use -DeltaV but a variation of ZeroDeltaV.



It doesn't look like the new 0G0B01 version uses Zero Delta V after all - I had 3 missed terminations out of 4 cells a couple of days ago.

The cells were old 1000mAh NiCads being charged at 400mAh The first 3 failed to terminate and got to about 2750mAh before I took them out of the charger. The fourth cell terminated at 968mAh...

IMHO it would be best if the unit was able to terminate the charge based on Negative Delta V, Zero Delta V and also Delta T. The preferred order would be Delta T, followed by Negative Delta V with Zero Delta V left as a fail safe for when both of the other termination methods fail.


----------



## LuxLuthor

I might as well put this in this C9000 thread as well as the other general one. TorchBoy pointed out that if you put in a battery, choose "cycle", choose 2 cycles and let it run.

Mine first charged, then 2 hour wait, then discharged, then I think an hour wait, then charging (2nd time). During this 2nd charging, if you push the up or down button it will display "1" for which cycle, and the mAh it recorded into memory for the previous d/c.

In this case, my actual 1st cycle d/c was 1568 mAh (which I saw on rest after 1st d/c), then the recorded display repeats the first two digits, and displays "1515" rather than "1568" I have the newer revised version which terminates properly, and does not overheat...but this is a bug. Not of a lot of significance, but a bug.


----------



## TorchBoy

LuxLuthor said:


> In this case, my actual 1st cycle d/c was 1568 mAh (which I saw on rest after 1st d/c), then the recorded display repeats the first two digits, and displays "1515" rather than "1568" I have the newer revised version which terminates properly, and does not overheat...but this is a bug. Not of a lot of significance, but a bug.


 :twothumbs 

A quirk rather than a serious flaw?


----------



## SilverFox

Hello LuxLuthor,

I have seen the repeating numbers, now that I think about it. I remember thinking it unusual that you would get something like that. I was looking for the missing middle digit.

Now I have to see if my current unit does this or if it was just with the original unit.

Tom


----------



## TorchBoy

Tom, I realised after getting the same thing with AA cells with four digit capacities that the middle digit of three is only missing if the capacity is less than 999mAh, because there is no first digit, eg " 5 5", but that only became obvious after getting some larger repeated capacities, eg "1313".

FWIW both my old and new units have shown it and I confirmed overnight that it displays the repeated value for the first cycle even after the cycling has finished.


----------



## LuxLuthor

I would be doubtful that MAHA would consider this a significant enough issue to allow another unit replacement as compared to the overheating, and failure to terminate.

I am still highly recommending this charger, even with this "quirk."


----------



## TorchBoy

What do you think of my problem with high current on discharge, slot 1 only? See post 256 for a pic, at 1180mA in discharge mode. Is it serious enough to complain louder (my last email to Maha didn't get a response)?


----------



## SilverFox

Hello Ian,

On that issue, I would send them another email. If that doesn't bring a response, let me know and I will call them on your behalf.

Tom


----------



## VidPro

SilverFox said:


> What do you think triggered the end of charge termination?
> 
> Tom



the charger just gave up 
i can TRY and explain the LOWER voltage. it really isnt lower is it?
the voltage is RISING on the "RESTED" voltage between pulses.
it is becomming "charged"
The Voltage is Lowering on the Pulse, the Pulse VOLTAGE is relative to the current its being charged at.

ON pulses, that impedance or resistance thing is changing, over time.

the voltage being punched into the cells is mabey as high as 7V say, but the batteries are not "accepting" the charge, especially at first.
the batteries are more like an OPEN curcuit, due to age , crystal formation, lack of metal on the plates , and stuff like that.
as the battery gets charged, and the metals move back into the plates (so to speak) the chargers voltage starts hitting the battery for real instead of just passing on the Open curcuit. 

i bet if you seperated the cells, and cycled them low a few times , the graph your seeing would change drastically.
but at any HIGH rate of charge, with a high voltage differential to get to the charge current desired would have the same visual effect.

if the battery was being charged via a specific VOLTAGE, you would only see a rise, but because it is being charged via a specific CURRENT, the voltage must rise to ACHIEVE that same current, when the battery is not accepting the charge, or the resistance is very high.


----------



## VidPro

Continued . . .
so in the above graph the PACKs voltage (the LOWER part of the graph line) increases, then vdrops, because Vdrop termination is based on the battery not the charge voltage, the charger terminated, because of a 0DV or a -DV.

now to attempt to bring it back on topic.
when you insert the cell into the charger here, your discussing:
1) the charger hits it with some voltage (say 3V)
2) the voltage is read at the "top" of the pulse or when voltage is applied by the charger
3) the "resistance" HIGH thing is displayed if the voltage required to get to the current is SOO high, that there is an asumption that the cell is ruined.
4) the second voltage displayed, is JUST like the graph above, its the voltage DURING charge
5) wheras most of the vdrop detection and voltage readings that are normally displayed are after the Pulse , or charge is removed (rested slightly).

i dont have that charger yet, just was reading up on it, via this great thread, but silver posted a Challenge  so i attempted an analisis, it might not be correct. but its a good guess.


----------



## SilverFox

Hello VidPro,

Nice explaination...

However, I believe the Schulze actually terminates on the charging voltage, and not the resting voltage. I am not sure of this, but in this example it seems to be checking the resting voltage as well.

The internal resistance of the pack is reducing during charging, but is still too high to end up with cool batteries during a 1C charge.

At any rate, these cells have drastically reduced capacity and now have been recycled.

Tom


----------



## LuxLuthor

I'm amazed at how fast Li-Ions lose their capacity when in settings like laptops, phones, cameras where they sit on charging cradles and have low level draining use on standby...not to mention how long they sat on some retailers shelf before being sold to you....using up their 2-3 year lifespan for good performance.


----------



## wjb3

delete, found answer


----------



## SilverFox

Hello Ian,

I finally got around to exploring the missing and repeating digit "feature" when using the cycle mode.

It appears to only affect slot 1, and only shows up on cycle 1. The other slots do not seem to be affected and I am getting correct numbers for the other cycles on slot 1.

Maha is aware of this, and will probably cover it during an incremental "improvement." I believe the units that were sent in to Maha for the original improvement will have this quirk removed.

Tom


----------



## wptski

Tom:

Hey, I've never noticed the digit bug yet! How many hours of charger watching have you logged?? :hahaha:


----------



## LiteTheWay

yep, I've got an 0G**** version and no digit bug ... so far.


----------



## Power Me Up

7histology said:


> yep, I've got an 0G**** version and no digit bug ... so far.


I've got an 0G version with the problem...


----------



## dekelsey61

Hi,
I have a question for you all. On the C9000 charger in the R/A mode which Ma charge rate would you get the highest discharge capacity if you are discharging at a rate of 500Ma on both settings, at a charge rate of 1400Ma or 1100Ma? I am thinking it might be the 1100Ma charge rate. If so, why would that be? Thank you for your replies.
Dan


----------



## wptski

dekelsey61 said:


> Hi,
> I have a question for you all. On the C9000 charger in the R/A mode which Ma charge rate would you get the highest discharge capacity if you are discharging at a rate of 500Ma on both settings, at a charge rate of 1400Ma or 1100Ma? I am thinking it might be the 1100Ma charge rate. If so, why would that be? Thank you for your replies.
> Dan


Dan:

The manufacture rates their cells at .2C but "normally" a lower discharge rate will result in a higher mAh result! That being said, I've seen cells give the same results at 1000ma and 500ma too on the improved C9000.


----------



## SilverFox

Hello Dan,

If I understand you question correctly... you are discharging at 500 mA and varying the charge rate between 1100 mA and 1400 mA. Is this correct?

If it is, you should get roughly the same capacity at both charge rates.

Tom


----------



## dekelsey61

Tom,
Thank you for your reply. That is right what you said and that is what I am doing.
Dan




SilverFox said:


> Hello Dan,
> 
> If I understand you question correctly... you are discharging at 500 mA and varying the charge rate between 1100 mA and 1400 mA. Is this correct?
> 
> If it is, you should get roughly the same capacity at both charge rates.
> 
> Tom


----------



## TorchBoy

SilverFox said:


> Hello Ian,
> 
> I finally got around to exploring the missing and repeating digit "feature" when using the cycle mode.
> 
> It appears to only effect slot 1, and only shows up on cycle 1. The other slots do not seem to be effected and I am getting correct numbers for the other cycles on slot 1.
> 
> Maha is aware of this, and will probably cover it during an incremental "improvement." I believe the units that were sent in to Maha for the original improvement will have this quirk removed.
> 
> Tom


Hi Tom. I would personally say that the other slots are not *a*ffected. 

Any word on when the fix will be included on stock units?


----------



## Handlobraesing

I just ordered mine from Thomas Distr. I should be in for good game or bad game?


----------



## SilverFox

Hello Ian,

What? I consider that "feature" a "special effect..."  

No idea on any time frame.

Tom


----------



## Handlobraesing

I really wish you could flash the firmware on this thing via USB or even returning the EEPROM chip to factory for reflash, like the good old days with PCs.


----------



## wptski

I have two improved C9000's and have noticed that the input capacity on Slot#1 is always a good percentage lower than the other slots!

I just got some PowerEx 2.7Ah cells and noticed that on them along with others too. I discharged them at .5A and those same cells came out lower too by 50-76ma which is 25% of the difference noticed on the input capacity. It appears that the input capacity for that slot "may" be incorrect? I notice that the charging current for that slot is always lower than the others too!

Anyone else notice this too??


----------



## TorchBoy

My slot 1 discharges at up to 1181mA.  Haven't chased that one up yet.


----------



## wptski

TorchBoy said:


> My slot 1 discharges at up to 1181mA.  Haven't chased that one up yet.


How does Slot#1 compare to the others while charging, current wise?


----------



## TorchBoy

Can't say I've noticed any difference.


----------



## Handlobraesing

Anyone notice the displayed voltage during discharge is unnaturally low? Mine shows around 1.08v while discharging 2650mAh AA at 600mA. 

Fluke 87-V shows the load is being switched at 0.5Hz, but I wonder if this truly cause the cell to behave the same as under true resistive load. 

The cell voltage measured during discharge is clearly higher on external meter than the display and when the cell is loaded with a resistor to approximately 600mA with a resistor, it's also higher than 1.09v. 

Using Fluke 87-V to record the instantaneous low, it doesn't dip below 1.16v, so 70mV is error?


----------



## TorchBoy

Actually I have noticed low discharge voltages, Handlobraesing. I thought it was just the "crap" cells I was testing at the time.


----------



## Handlobraesing

We know batteries behave very differently depending on discharge current.. The question is if 0.5Hz PWM to yield TWA of programmed current would cause the battery to operate at the same efficiency as a true constant current.
(1A 0.5Hz, 10% duty cycle would be 100mA time weighed avg.)

There's also something about this charger that doesn't add up. 

Mode: Break-in, 2700mAh (charge-->discharge-->charge)
Charge current, dialed in 270mA
Measured charge per display ~268mA
Time elapsed 600 minutes/10 hours

Ah = A x hr, therefore 268mA x 10 hrs = 2680mAh
The display says cumulative charge is 2410mAh

2680-2410=270.

270/2680 =10.7% error.

270mAh unaccounted. Current and/or time base are significantly off.
willchueh, please explain this.


----------



## bmoorhouse

I'm back after charging AAA's for the first time. I have the 2nd version of the C9000 and have charged 2000mah AA's at 500ma without problem, so I set the C9000 to charge three 800mah AAA's at 200ma.

All three terminated at about the same time with about the same capacity, but they went much longer than I expected. I didn't write down the specifics before pulling them out, but the capacity was just over 1200mah and the time was just over 420 minutes. I expected something closer to 5 hours and about 1000mah.

Is what I saw normal? Damaging to the batteries?

Also, I just reread a lot of the posts and saw that the C9000 always uses a 2-hr 100mah topoff charge. Does that mean that it is unadvisable to leave any AAA batteries which typically have about 800mah capacities on the charger for any length of time after termination. It seems those two hours would put a 25% overcharge every time.


----------



## SilverFox

Hello Bmoorhouse,

Battery manufacturers recognize that NiMh batteries do not give a reliable, strong, end of charge signal at lower charge levels. They recommend two ways of charging. 

The first is a timed 0.1C charge for up to 16 hours. This is a good way to go, if you run your cells all the way down each time, and if you have time for slow charging.

The second recommendation is charging in the 0.5C - 1.0C range. At these rates, a strong, reliable, end of charge signal is generated and proper termination can be achieved. A bonus is that it takes less time to charge, and will properly charge the cell if it has only been partially discharged.

The reason they "jump" over the rates between 0.1C and 0.5C is that the charge termination signal strength can be unreliable and now the age factor of the cell, and environmental conditions, can play a part in whether the signal is strong enough to terminate the charge. In addition, charging at these rates (above 0.1C) can damage the cells if the charge is not properly terminated.

I should also point out that at low charging rates, the efficiency of the charge is greatly reduced. 

I would recommend that you charge your 2000 mAh AA cells at the default 1.0 amp rate.

Moving on to your AAA cells...

Maha "adjusted" the charge termination algorithm, making it more conservative. The more aggressive termination algorithm worked great for 0.5C - 1.0C charging, but it would sometimes miss the termination signal at lower rates. The conservative termination algorithm will terminate all but the crappiest of cells at any charge rate, but at low rates, there still is the possibility of a slight overcharge.

You are charging at a 0.25C charge rate. I don't charge at that rate, so I don't know what the charge efficiency is at that rate. At 0.1C, you need to put 150 - 160% into the cell to fully charge it. At 1C, you need to put 105 - 110% in. If we extrapolate a little, 0.25C is closer to 0.1C, so it may take 130 - 150% for a full charge.

Your 800 mAh cells took 1200 mAh of charge, which is 150%. I personally think that is a little high, but it is in the ball park.

The problem comes after the charge is completed.

Charging at a 0.25C charge rate, means that you are going to get a slight overcharge because of the weak termination signal. Now, at the end of the charge, you add the 2 hours of 100 mA topping charge, and you end up with overcharged cells. Fortunately the overcharge rate is 0.125C, which is just slightly over the "safe" 0.1C rate. This is where the condition of the cell and environmental conditions come into play. 

This seems to work, but it may not be taking the best care of your cells.

Let's look at another way of charging your AAA cells.

I have some 850 mAh AAA cells that test out to 700 mAh. 

When I charge them at the C9000 default rate of 1000 mA, the charge terminates at around 36 minutes. This works out to an input of around 600 mAh. Adding the 2 hour top off charge brings me up to 800 mAh input. That works out to around a 114% charge.

Examining the charge I find that the cell is not actually completely charged. It is very close, but not quite full. The cell temperature rises up to around 95 F, and I am very pleased with this charge rate.

When I drop down to charging at 400 mA, the charge terminates at around 630 mAh. Add to this the top off charge and we have a total charge of around 119%. These cells come off fully charged.

Further dropping the charge rate to 200 mA gives me results similar to what you are seeing. At 200 mA, the cells terminate at around 1010 mAh. This works out to about 144% before the top off charge. When we add the top off charge, we are around 173%. Even with lower charge efficiency, I think this is pushing things a little.

It is interesting that when I use the 400 mA charge rate, the cell temperature is higher than when I charge at 1000 mA. At 400 mA, the cell temperature gets up to 105 F.

When I look at the numbers, I think the best charging rate for the AAA cells is the default 1000 mA rate. If this seems a little high, you can adjust it down to a minimum of 1C. 

I think it is counter productive to charge cells at low rates, unless you know the state of charge of the cell before charging, and you terminate the charge manually by setting a timer.

Tom


----------



## NA8

*Re: Improved Maha C9000…*

After reading through this thread, I wonder what the results would be of wptski comparing a brand new set of 2.3Ah duracells with the one's he's been cooking for so long


----------



## NA8

*Re: Improved Maha C9000…*



webfors said:


> ...
> Regarding the high temps Bill has seen, I have yet to see such high temps. ... Looks like the high capacity batteries can handle the c9000's 2 amp charge just fine. However, I have yet to experience any really high temps with the new version. I do wish I had a method to accurately test the charging temps. My advanced two finger touch test tells me the batteries are only warm, and spike to 'almost hot' for a brief moment at the end of the charge cycle, and cool down quickly.
> ...



Seems like this is what everyone should be experiencing. The temperature is supposed to rise at the end of the charging cycle. I don't understand all these posts by people saying they're batteries are screaming hot while charging and putting fans on them. If they're hot, thats it. They're done. If they don't have a charge that's sufficient, then you're going to have to recycle them one way or the other (garbage or refreshing). Am I missing something ?


----------



## wptski

NA8:

To answer your first question or suggestion. Duracell made 2.3Ah and 2.4Ah but like many other brands, you'll not find cells of that capacity anymore.

On the heat issue. I connected one cell outside the C9000 and another cell was inserted. I monitored the temperature of both and the cell that was outside the unit was 30F cooler. You can charge a cell at 1C with constant current and it won't get over 110F. There is some thought that PWM in itself cause heat.


----------



## NA8

*Re: Improved Maha C9000…*

I've got a couple more of these Maha C9000 threads to read through. I expect it'll all become clear in time.


----------



## TorchBoy

*Re: Improved Maha C9000…*

Ah, this is actually the thread I was looking for to ask: Does anyone know if the latest production run, 0G0D01, has new firmware which fixes the cycle recording error?


----------



## Tekkanano

TorchBoy said:


> Ah, this is actually the thread I was looking for to ask: Does anyone know if the latest production run, 0G0D01, has new firmware which fixes the cycle recording error?



Well, I bought a C9000 from Thomas Distributing on 6/2/07 and that one has the cycle recording error. I guess it'll be a while before they stock the new ones that are fixed, but by then someone will find another bug.


----------



## SilverFox

Hello Tekkanano,

This charger has been under the microscope for quite awhile now. Anyone who takes the time to read all the threads about its evolution and improvements should understand exactly what they are getting.

The C9000 has to be the most scrutinized consumer charger available. I am not sure there is anywhere for new bugs to hide.

Tom


----------



## europium

Handlobraesing said:


> We know batteries behave very differently depending on discharge current.. The question is if 0.5Hz PWM to yield TWA of programmed current would cause the battery to operate at the same efficiency as a true constant current.
> (1A 0.5Hz, 10% duty cycle would be 100mA time weighed avg.)
> 
> There's also something about this charger that doesn't add up.
> 
> Mode: Break-in, 2700mAh (charge-->discharge-->charge)
> Charge current, dialed in 270mA
> Measured charge per display ~268mA
> Time elapsed 600 minutes/10 hours
> 
> Ah = A x hr, therefore 268mA x 10 hrs = 2680mAh
> The display says cumulative charge is 2410mAh
> 
> 2680-2410=270.
> 
> 270/2680 =10.7% error.
> 
> 270mAh unaccounted. Current and/or time base are significantly off.
> willchueh, please explain this.


He did, here: https://www.candlepowerforums.com/posts/1759840&highlight=90%#post1759840



willchueh said:


> Mike abcd,
> 
> Regarding your earlier question about the "charging efficiency:"
> 
> * The current shown on the screen is the "peak" current which is only applied 90% of the time.* For example, if you select 2000mA, the current is 2000mA for only 2.0 seconds, and 0mA for 0.2 seconds. The brief rest time is part of the pulse charging and is also used to measure voltage, etc, since we do not want to include the resistance of the metal contact, etc and noises from high frequency used in the switcher.
> 
> So the number shown is not fudged for "charging efficiency."
> 
> William



Eu


----------



## Codeman

Has anyone seen the charge rate selection go backwards (1000, 900, etc) instead of the usual forward (1000, 1100, etc)?

That happened to me 2 nights ago. After powering down, it didn't happen again.

That was with an early 0FAB02. It had faulty AA cell detection on slot 1 and I just received a replacement 0G0D01 from Maha today, so I probably won't see it again.


----------



## digitor

*Re: Improved Maha C9000…*



Codeman said:


> Has anyone seen the charge rate selection go backwards (1000, 900, etc) instead of the usual forward (1000, 1100, etc)?



Yes, if you press the down arrow button when selecting the rate.

Cheers


----------



## Codeman

*Re: Improved Maha C9000…*

I can write software to maintain several billion records at work, yet I can't see what's right in front of my face - duh!


----------



## Drakis

Hi. It's my first post on this forum.
Just to say that i got mine on EBAY 2 days ago, brand new, and it's version is 0G0E01.
Now just a question:
I have 4 SONY 2300mah AA and i use it on a digital camera.
I have been using them almost daily for over a year now.
Recently i'm noticing that the runtime is getting lower, which i think is logic.
What i would like to now, is what can i do to "refresh" them to get to the fullest they can still get to.


----------



## Codeman

Welcome to CPF, Drakis!

The Refresh and Analyze mode is what you're looking for, though you may need to do more than 1 pass.


----------



## Drakis

I'll do that. Do you have any recomended charge/discharge rate?
I was thinking of doing 3 cycles, at 1200/500 or 1300/400
These are 2300mah batteries.


----------



## tino_ale

Refresh mode should work, but if it doesn't improve perf, last chance would be is break-in. But this is long, it will take up to 45 hours to complete... it should be started batts empty so you need to discharge them first (same for refresh, which starts with a charge). Maha recomment to run this break-in every 30 cycles on Ni-MH.

I would think that if you are trying to bring your batts to best perf, you should use lower currents, and assume your batts are not 2300mAh anymore. If I were you I would use 1Amp charge and 400mA discharge max.




Drakis said:


> I'll do that. Do you have any recomended charge/discharge rate?
> I was thinking of doing 3 cycles, at 1200/500 or 1300/400
> These are 2300mah batteries.


----------



## Drakis

tino_ale:

I didn't know that i should discharge them first.
I will do as you said, discharge, then 3 cycles of 1000/400 (c/d).

Thanks for the prompt replies!


----------



## tino_ale

Both R&A and break-in will do a charge/decharge/charge sequence.

Since R&A uses peak detection to terminate the charge, I guess it will terminate charge even with relatively full batts... but with totally full batts, I wouldn't bet on a proper termination. I believe RC guys re-peak they packs just before races, but don't advise to do it more than once, so I guess there is a risk for non termination...?

break-in uses slow charge, 0.1C, which should not harm the batts even when full... but still I would personnally dischage them before. I'm not sure it's healthy for a fully charged batt to receive 0.1C for 16 hours (this is break-in charge).

Discharging the batts sure doesn't do any bad, so this is what I would do. If you can keeps us posted on how capacity evolves after each cycle. I'm interrested in the results!



Drakis said:


> tino_ale:
> 
> I didn't know that i should discharge them first.
> I will do as you said, discharge, then 3 cycles of 1000/400 (c/d).
> 
> Thanks for the prompt replies!


----------



## Drakis

Ok...
I made a mistake and did a refresh/analyze at 1200/500 (c/d), on just two of the four cells.
The results were:

cell 1 -> 1708 -> 1928 (106min)
cell 2 -> 1701 -> 1966 (108min)

First is capacity after discharge then the capacity after done.
I will do testing with just these 2 cells for the moment.


----------



## Drakis

After 1 cycle, here are the results:

Cell 1 -> 1996
Cell 2 -> 2006

Done using 1000/400 (c/d) rates.


----------



## TorchBoy

*Improved improved Maha C9000…*

I received an improved improved version this morning, batch 0H0AA. This version has a brighter screen than all the previous versions I've seen. (Does anyone thing it weird to have beamshots of a battery charger?  )















That last one is a chopped image, not both screens on at the same time.

I thought it might be interesting to do a difference combination, which means that only things which are different between two pictures show. If a pixel is the same brightness and colour it comes out black. The same-brightness line is definitely skewed to one side.


----------



## Bones

*Re: Improved improved Maha C9000…*



TorchBoy said:


> I received an improved improved version this morning, batch 0H0AA. This version has a brighter screen than all the previous versions I've seen. (Does anyone thing it weird to have beamshots of a battery charger?)



There's can certainly be no doubt they upped the brightness by a significant degree, which now begs the question, why?


----------



## Black Rose

*Re: Improved improved Maha C9000…*



TorchBoy said:


> I received an improved improved version this morning, batch 0H0AA. This version has a brighter screen than all the previous versions I've seen.


Wow. I hope you don't live near an airport :devil:


----------



## Yoda4561

*Re: Improved Maha C9000…*

Man, the thing is already too bright, they must be trying to cater to the CPF "more lumens is better" market.


----------



## hank

I'd bet they're just manufacturing these using generic currently available LEDs, which are a lot brighter than the LEDs that were available, oh, a week ago (grin).

Waste of good electrons, though.


----------



## Codeman

Yikes! My older one is too bright. I'd be putting limo tint on one of the new ones!


----------



## TorchBoy

*Re: Improved improved Maha C9000…*



Bones said:


> There's can certainly be no doubt they upped the brightness by a significant degree, which now begs the question, why?


So all the flashaholics will buy another one, of course. 

Brighter is better!


----------



## 45/70

Codeman said:


> Yikes! My older one is too bright. I'd be putting limo tint on one of the new ones!



Humm. That's a great idea Codeman! I may do just that. I have one of the newer ones, I guess (OG0IA) and the back light _*REALLY *_bothers me. "Why", is a very good question.

Dave

Edit: Actually, I think maybe it's a 0G0IA. It's hard to read after looking at the display.


----------



## DynoMoHum

Wow... I guess I should have stayed around this forum a bit longer after I had initially joined. Maybe I would have learned that my MH-C9000 had a problem... 

But seriously... I bought a MH-C9000 a few years back, played with it a bit, then mostly started using a Energizer 15 minute timer and ignored my MAHA charger and really made no attempt to look into more info on the MAHA charger. 

Now i recently bought some new LSD AA cells and broke out my MH-C9000 charger to do some evaluations of my new cells (and some old ones as well). I start doing research on things and find out that I may have a outdated possibly defective (to some degree or another) charger. Now I read more or less each and every post in this thread now, took me several hours. 

I'm still somewhat confused as to what I should do with my charger. The code on the bottom of it is 0FAB0Z, I don't recall exactly when or even where I bought it (most likely from Thomas Distributing). I think theoretically it is likely still under warranty since I don't think these have been available for more then 3 years as of yet (although will be soon).

So, the bottom line question is... What really are my risks of using this thing? 

From what I read, it sometimes failed to terminate on 'some' cells. It got some cells hotter then is desired... It seems that AAA cells and/or accurate termination of these was more of a problem then was seen with AA cells...

Furthermore, from what I read... Some people continued to see some termination issues even on newer 'code' or 'updated' models, possibly related to a smaller set of conditions, etc...

So what is the bottom line for me and my old 'code' version of this charger? should I fear it? should I replace it? or should I just keep using it?


----------



## Black Rose

DynoMoHum said:


> Furthermore, from what I read... Some people continued to see some termination issues even on newer 'code' or 'updated' models, possibly related to a smaller set of conditions, etc...


I have one that is almost 2 years old (0G0KA) and I have seen missed terminations a couple of times, but those were with really really bad cells from my pre-CPF days.



> So what is the bottom line for me and my old 'code' version of this charger? should I fear it? should I replace it? or should I just keep using it?


If you are within the warranty period, call Maha and see what they say. They have really good customer service and really stand behind their products.

EDIT: Here is a link to the "official" Maha C-9000 Support/FAQ thread.


----------



## DiverDn

DynoMoHum said:


> Wow... I guess I should have stayed around this forum a bit longer after I had initially joined. Maybe I would have learned that my MH-C9000 had a problem...
> 
> But seriously... I bought a MH-C9000 a few years back, played with it a bit, then mostly started using a Energizer 15 minute timer and ignored my MAHA charger and really made no attempt to look into more info on the MAHA charger.
> 
> Now i recently bought some new LSD AA cells and broke out my MH-C9000 charger to do some evaluations of my new cells (and some old ones as well). I start doing research on things and find out that I may have a outdated possibly defective (to some degree or another) charger. Now I read more or less each and every post in this thread now, took me several hours.
> 
> I'm still somewhat confused as to what I should do with my charger. The code on the bottom of it is 0FAB0Z, I don't recall exactly when or even where I bought it (most likely from Thomas Distributing). I think theoretically it is likely still under warranty since I don't think these have been available for more then 3 years as of yet (although will be soon).
> 
> So, the bottom line question is... What really are my risks of using this thing?
> 
> From what I read, it sometimes failed to terminate on 'some' cells. It got some cells hotter then is desired... It seems that AAA cells and/or accurate termination of these was more of a problem then was seen with AA cells...
> 
> Furthermore, from what I read... Some people continued to see some termination issues even on newer 'code' or 'updated' models, possibly related to a smaller set of conditions, etc...
> 
> So what is the bottom line for me and my old 'code' version of this charger? should I fear it? should I replace it? or should I just keep using it?



I was looking for a thread like this, but could not find it so I started another thread asking if there had been any changes, now I know, thanks for bringing it to the top.

I would give Maha a call and see what they say. I have read here that they have very good customer service which is why I am going to buy one of there chargers very soon.


----------



## DynoMoHum

Thanks for pointing me to the other thread Black Rose, I'll start reading that one see if I can find any further info that will ease my mind with regard to continuing to use this older version of the charger.

In the mean time I tried to call MAHA support and got no answer at all, I let it ring and ring and ring... Not sure if they are closed for the holidays or what, but it seems a tiny bit odd that I never got a answering machine or nothing. I tried the 1-800 number listed on their web site as well as the 626 area code number, same thing...no answer. I eventually submitted a online support request using their web form. So for now I just wait to see what they say... and go read a bit more in that other thread.


----------



## DynoMoHum

Wow... talk about service. Within minutes of submitting a online support request with my questions and/or concerns about getting the old unit replaced I got a email response asking for my shipping address... I'm impressed.


----------



## Bones

DynoMoHum said:


> ...
> 
> So what is the bottom line for me and my old 'code' version of this charger? should I fear it? should I replace it? or should I just keep using it?



I have an original edition MH-C9000, and chose to keep it even though it could have been exchanged for a revised version. Firstly, its more aggressive termination methodology results in a more complete primary charge, albeit at an increased risk of missed terminations, especially with lessor quality and aged cells. Secondly, it has a 20000mAh maximum capacity cutoff, which means it can charge C & D cells with the appropriate (custom-built) adapters. The revised version has a 4000mAh maximum capacity cutoff.

However, before you make any decisions as to its disposition, you need to determine whether you have actually have an original edition MH-C9000. Although the code 0FAB0Z is indicative of an original edition, it's not assured.

The easiest method is probably to watch the voltage at the time the primary charge terminates with a quality cell such as the Eneloop. The revised version will stop the charge at 1.47 volts, whereas the original version will usually push the Eneloop well past 1.50 volts. As well, be sure to set the charge rate at 0.5C or higher and then monitor the end of the primary charge cycle to ensure the charge terminates properly.

Incidentally, regardless of the charger used or the charge rate chosen, it's always a good idea monitor the first few charges of any cell at a given charge rate to ensure proper termination.


----------



## Mr Happy

As Bones implied, there are some people out there who would actually prefer the earliest version of the C9000 and would rather have that than a recent model. With every revision of a product there are pluses and minuses, and not everyone necessarily thinks the same way about what is a plus and what is a minus.

Do not be too worried about missed terminations. The truth is that all chargers can miss a termination some time or another, either from old and crap cells, or brand new cells that have not broken in yet, or from using too low a charge rate.

If you learn about what is a good charge rate to use (0.5C - 1.0C), and take special care to watch brand new cells or very old and crap cells, there is no cause for alarm.


----------



## DynoMoHum

I'm all but certain I have one of the original versions, reason being that when it discharges it stops at 1.0 volts, as I understand it the newer version cut off the discharge at 0.9 volts .

Either way MAHA has already got my shipping address and has told me they will send me a updated version out sometime this week. 

I do think I fully understand the pros and cons of the new vs. old versions of this charge. Normally I'd probably be one to just stick with the older version since it seems that it will typically charge a bit more fully. Yet I've recently come to think I'd be better off not being so agressive on getting full charges and lean toward trying to keep my cells in good health. 

When doing some full charge/discharge cycles on some new Eneloops and GP LSDs I was finding that at least two cells out of the four in the charger would tend to get quite warm. (typically this was the two center slots in the charger I have) This was what originally got me to thinking if there may have been some issue with my charger. After reading so much about how 'easy' this charger was supposed to be on cells I couldn't understand why it was getting my new cells so warm. 

But anyway, like I say... MAHA has said they will be sending me a new charger this week, so I guess the decision has already been made.

I do greatly appreciate the additional information and opinion on what the pros and cons of the older vs new versions are.


----------



## digitor

*Re: Improved Maha C9000…*



Mr Happy said:


> As Bones implied, there are some people out there who would actually prefer the earliest version of the C9000 and would rather have that than a recent model.



I chose to keep my original version - the only missed termination I've had was once when charging a AAA at 500mA - now I charge them at 700 and have not had a problem since. I've considered getting a new version as well though, mainly for the different discharge algorithm, but now that my entire NiMH fleet is comprised of Eneloops, I don't suppose I really have the need... (Still, that's never stopped me before) 

Cheers


----------



## DynoMoHum

Well, UPS delivered my updated MH-C9000 today... the code on the bottom is 0101A (or maybe it's OIOIA) 

Running a battery in it right now... wondering if its peak voltage really is restricted to less then 1.5 volts...


----------



## TakeTheActive

DynoMoHum said:


> ...*UPS delivered my updated MH-C9000 today... the code on the bottom is 0101A (or maybe it's OIOIA)*...


How about: *0I0IA* (Number / Letter / Number / Letter / Letter)

Mine is *0H0AA* (Bought: Dec '08) so I guess you need to put your 'specs' on  (tri-focals here! )

Looks like a 'New Batch'.

Best of luck with it - GOOD CHOICE (from the FIRST time around)! :twothumbs


----------



## JaguarDave-in-Oz

DynoMoHum said:


> Well, UPS delivered my updated MH-C9000 today... the code on the bottom is 0101A (or maybe it's OIOIA)


I bought one in Australia a few days ago and wondered was it the most up to date version (not that I had any reason to think it wasn't since the seller is a good one) and its code is the same as yours that came direct from Maha so I guess that pretty much answers my question.

PS it looks like 0101A to me with my reading glasses on........


----------



## Apollo Cree

Is the consensus that current models of the C9000 do not have much of a problem with failure to terminate? I'm seriously considering buying one. 

Any suggestions as to where to purchase them from? Discount codes, etc.?


----------



## Rexlion

There has been discussion about charging cells externally with wires held on by magnets or clamps. But I think I read that for termination the temperature sensors can come into play, at least some of the time anyway. If a cell is charged externally, doesn't that negate the sensors? 

I realize that external charging would usually involve high capacity C and D cells, and the 4A cutoff will be a factor. But if we restart the charge cycle once or twice to reach max capacity, at some point the charger has to figure out when to terminate "normally". Is it really wise to take away one of the charger's termination cues by charging externally? I mean, it seems like if those temp sensors weren't important, MAHA would've left them off. What do you all think?


----------



## Rexlion

Apollo Cree said:


> Is the consensus that current models of the C9000 do not have much of a problem with failure to terminate? I'm seriously considering buying one.
> 
> Any suggestions as to where to purchase them from? Discount codes, etc.?


 I bought one in December. Best price I found was Thomas Distributing... and I didn't find any discount codes.


----------



## TorchBoy

Rexlion said:


> the 4A cutoff will be a factor.


4 Ah. The C9000 charges at a maximum 2 A.

Unless you're charging a very poor quality cell I really don't think it would get hot before the maximum voltage termination cue (~1.47 V) stopped it.


----------



## regor_nono

Hi. I got a theory on the break-in mode of C9000. It takes 16 hours on 0.1C charge for the break-in right? That will net the battery a 160% charge, which is basically an overcharge. So, to keep it on 100%, I could use the formula [battery cap]/16 hours/0.1C. Using it, if I have an eneloop with 2000mAh cap, that's 2000/16/0.1 = 1250. The value 1250 is the value that I'll key in when asked for the capacity in the break-in mode.

I don't know if this is already posted before in this thread, 13 pages is too many to plow through. If there is, please enlighten me.

I don't have a C9000, but I'm planning to get one after 2 months.

Your thoughts please. Thanks!


----------



## Mr Happy

The break-in process is supposed to give the batteries a 160% overcharge. It doesn't harm the batteries due to the small charging current used.

If you enter a lower capacity for the break-in cycle you will not get the full benefit of the conditioning process and you will get a less than expected capacity measurement.


----------



## TakeTheActive

regor_nono said:


> ...*I don't know if this is already posted before in this thread, 13 pages is too many to plow through. If there is, please enlighten me*...



1.) Welcome to CPF! :welcome:

2.) If you're not willing to invest YOUR time to find an answer to YOUR question, why should volunteers invest THEIR time?  READ and LEARN! LOTs of great info buried in the CPF Archives here.




CLICK on my Sig Line LINK for a place to start.​


regor_nono said:


> ...*I got a theory* on the break-in mode of C9000... ...which is basically an overcharge. So, to keep it on 100%, I could use the formula [battery cap]/16 hours/0.1C... ...an eneloop with 2000mAh cap, that's 2000/16/0.1 = 1250. The value 1250 is the value that I'll key in when asked for the capacity in the break-in mode...



3.) Bad theory. Charge EFFICIENCY goes down with Charge RATE. 

Please read: *Theory: Nickel-Based Rechargeables {2004}* by *jtr1962*.​


regor_nono said:


> ...I don't have a C9000, but I'm planning to get one after 2 months...



4.) What charger are you using now?​


----------



## regor_nono

1. Thanks for the welcome!

2. Sorry, I haven't read all the posts on THIS thread, one day doesn't seem to be enough, but I did read the links on your picks. I think I got through 2/3 of those links, plus the Maha C9000 and C808M support threads. I held off creating an account until this week. I did invest part of my sleeping and work time reading those, but for a month since I started, I don't think I can do it all in one go. Nevertheless, I will keep reading. Those battery holder setups are starting to get my attention.

3. Well, there goes my theory. Just a thought, if charge efficiency goes down with charge rate, why the Break-In mode? Why not just the Refresh and Analyze mode? I do know that it is posted on the duracell site that a forming charge of 0.1C for 12 hours is beneficial. I thought of this because I've read in one of the posts that the break-in mode will overcharge the cell, and overcharging is bad.

4. I got a Maha C808M. I went through 2, the first one was a dud, kept blinking DONE on the last 3 bays even when I shuffled the cells, and they were eneloops! I refunded it and bought another one from another merchant. This one's really great, it's going through 3 sets of 8 AAs and AAAs mixed. Got a problem with termination for new AAAs though, when in condition mode and soft charging. Other than that, it IS a great charger!


----------



## riksilvers

One thing i've noticed is that slot 1 & 3 discharge different from 2 & 4 as if in pairs. I've even rotated the batteries to see if it was something to do with their charge state. Version I have is 0101A. This may also effect charging too....comments !!!


----------



## TakeTheActive

riksilvers said:


> *One thing i've noticed is that slot 1 & 3 discharge different from 2 & 4 as if in pairs... ...comments !!!*


*You have too much spare time!* 

Please post your data to support this observation - let's see some tables, graphs, standard deviations, # of cells in sample, # of chargers in sample, etc...


----------



## airsy

*Newbie w/ a Maha C9000 Question or two*

Hello,

I'm newly registered to CandlePowerForums and, though I read this FAQ on "Reading and Posting Messages", I couldn't figure out where and how I should make a post with questions regarding my new Maha C9000. ("New thread" vs. "Reply to Thread"?) So I ended up here. My sincere apologies if I'm posting to an inappropriate place...if so, I'd be grateful for suggestion of a better place to post my Q's.

Just for context, I'm a relative "battery novice" who mainly uses rechargeable AA and AAA's for photography (Canon MR-EX14 Ring Flash and Canon SX10 IS camera) and for GPS unit, head-lamps, computer keyboard and mice. I've learned a lot lately from browsing threads on CPF (thanks Silverfox, Mr Happy, and other regulars  and was motivated by reviews & user remarks to augment my previous Maha C204W charger with a Maha C9000. Just received it about 2 weeks ago and have done ~6 chargings.

Question #1: This is simple and basic:

Is it perfectly fine to charge _different_ brands (and sizes, or capacities) of batteries _simultaneously_ in the 4 different slots of the Maha C9000? For instance, is it OK to place a PowerX 2700 mAh AA in slot 1 for Recharge, an Energizer 2000 mAh AA in slot 2 for Refresh & Analyse, and two 800 mAh Eneloop AAA in slots 3 and 4 for Cycling? Or are there any technical reasons such a practice is not recommended, as far as the health of the charger or batteries are concerned? 

Maybe I'm being "too cautious" in not assuming this is fine...but I'm a rank novice with battery usage and know-how so I wanted to check if "mixed charging" like this is harmless or not. (And I couldn't find an explicit answer after browsing about 15 CPF threads and reading the C9000 instructions and online FAQ at the MAHA wesite.)

Question #2: I just tried "Cycling" (3x w/ 1000mAh charge and 500mAh discharge) on two Energizer AA 2000 mAh batteries I've used for a while in a GPS unit (Garmin eTrex Vista HCx). The GPS seems to eat the batteries pretty fast, i.e. after a day of use. [Though, depending on "how" one uses such a unit, I guess "a day" might be more (or less) demanding.] Anyway, I was puzzled by the fact that the mAh capacities the C9000 reported for both batteries _decreased_ with each additional cycle. Below are the capacities, as read off the display by pressing the ^ key when the 3 cycles were "Done" for both batteries:

1st Cycle 2nd Cycle 3rd Cycle

Battery #1: 1946 mAh 1899 mAh 1883 mAh
Battery #2: 1567 mAh 1549 mAh 1523 mAh

I was surprised by this, since I expected Cycling to "revive" the batteries (especially the one running in the 1500's). As best I recall, the two batteries were purchased together, are ~2 1/2 years old, and have been recharged maybe 20 times on my old MH-C204W charger. (Don't recall if I ever "reconditioned" them on that charger...I was sloppy before, but after learning from CPF threads I'm now labeling batteries & keeping records .

Question #3: I've noticed that each time I've used my C9000, the leftmost slot (#1) has consistently been the one listing the highest final capacity when all the slots read "Done". That seemed like an improbable coincidence to me...does that not seem unusual to CPF cogniscenti? Granted, I haven't done that many runs...just about six (including two "Break-In's", each with 4 Eneloop 2000 mAh AA; two "Refresh & Analyse" runs for 8 Energizer 2500 AA (in two sets of 4), a standard "Recharge" and the "Cycling" described above in Question #2. Still, it seems strange that the leftmost battery I placed in the charger would always be the "best" battery of the bunch.
_________________

OK, thanks in advance for any comments, suggestions, or insights here!


----------



## pae77

I'll take a shot at #1. Since the slots on the C9000 are completely independent of each other (each one is like a separate charger), you can mix and not worry about matching, (e.g., charge an AA by brand X in slot one and an AAA by brand Y in slot 2, etc.).


----------



## bbb74

*Re: Newbie w/ a Maha C9000 Question or two*

Re #1 - as pae77 said, mix and match as much as you like, its fine.

#2 - Sounds a bit odd. You could try a Breakin on the batteries. Did you ever let the garmin totally flatten the batteries? Its possible some reverse charging of the weaker cell happened which has damaged it.

#3 - Try numbering each battery with a felt tip pen, and redo one of the ones you did before but swap the batteries around so they're in different slots, that way you can confirm if its a fluke, or if you really do have a problem


----------



## Turbo DV8

#4 - "Cogniscenti?" :huh2:


----------



## Mr Happy

Turbo DV8 said:


> #4 - "Cogniscenti?" :huh2:


Yeah, it's a typo. Should be cognoscenti of course...


----------



## Turbo DV8

Mr Happy said:


> Yeah, it's a typo. Should be cognoscenti of course...


 
Um, ah ... yes, of course, that's what threw me off!


----------



## brted

*Re: Newbie w/ a Maha C9000 Question or two*



airsy said:


> Question #2: Anyway, I was puzzled by the fact that the mAh capacities the C9000 reported for both batteries _decreased_ with each additional cycle. Below are the capacities, as read off the display by pressing the ^ key when the 3 cycles were "Done" for both batteries:



I don't think that's uncommon. It's kind of rare to be able to revive batteries. You could try a Break-in, but I don't know that you'll see much difference. I don't think you're really hurting the battery though. After you use it a few times, you will probably see the earlier capacity.



> Question #3: I've noticed that each time I've used my C9000, the leftmost slot (#1) has consistently been the one listing the highest final capacity when all the slots read "Done".



I've always suspected that on mine too. It shouldn't be a big difference and I'm not sure it matters too much. I always try to randomly assign batteries to slots (rather than put Battery 1 in Slot 1 every time) just in case.


----------



## WDG

*Re: Newbie w/ a Maha C9000 Question or two*



airsy said:


> Question #2: ...the mAh capacities the C9000 reported for both batteries _decreased_ with each additional cycle.



This probably has to do with the completeness of the charge on each cycle. Normally, the MH-C9000 tops off cells for two hours after termination (i.e. after it says DONE.) IIRC, CYCLE mode only tops for one hour after termination between cycles. This will cause the apparent capacity to decrease some.

Since BREAK-IN mode is the most accurate way to check cell capacity on the MH-C9000... I'm thinking that the best way to see what effect cycling has on cells would likely be to run a BREAK-IN, then CYCLE, then another BREAK-IN, to see what the change is from the first BREAK-IN to the second (discharging before each BREAK-IN, of course.)


----------



## jacknife

I saw a video on YOU TUBE where 4aas were placed in the c-9000 and the charger itself defaulted to charge all four batteries... Is this correct or do you have to program in EACH battery for simply charging the four .------------batteries or 3 or 2 or 1 ???


----------



## Mr Happy

jacknife said:


> I saw a video on YOU TUBE where 4aas were placed in the c-9000 and the charger itself defaulted to charge all four batteries... Is this correct


Yes. The C9000 defaults to charging each slot at 1000 mA if you don't press any buttons.


----------



## tandem

jacknife - if you do not touch the keypad on the C9000 it will time out and default to CHARGE and at a default rate of 1000.

If you happen to be charging Eneloops that'll be a charging rate of 0.5C (2000mAh / 1000mA) which is certainly acceptable. If all you ever charge are AA 2000mAh Eneloops you could use the C9000 without ever once touching the keypad.

The default 1000mA rate is too high for normal practice in charging AAA format cells which are frequently only 800mAh capacity, so if you want to treat those cells nicer, you'll have to touch a few keys on the C9000 when you load it up with AAA cells.

Obviously if you have different cells in each bay, and desire different charging rates (or other programs run) you'll have to let your fingers do a little walking over the keypad to tell the C9000 what you would like it to do. It can't read minds, nor can it apply settings you've entered for one bay and "clone" those settings to the other bays. In practice I don't find this to be a problem (and I have ~ 100 cells of different types and capacities) but some find it annoying.


----------



## jacknife

THANKS for that quick response , I am trying to learn the charger and Have read tons on the searches . I saw an in depth video on YOU TUBE on the Other charger the other companies - 900, I wish there was an indepth one on the C-9000 Thanks JK


----------



## jacknife

Thanks Too Tandem,, Yes presently All I have are Eneloop AA and AAA, I am for the first time starting to go Rechargable. And it seemed wise to go c-9000 with all that was written here. So if you put in 4 aaas at once the c-9000 would recognise that to and default to proper charge .. YES? all four?---But if you were charging 2AA s And 2AAAs you would set aa to 1000 and aaas to what??


----------



## Mr Happy

The C9000 does not know the difference between AAA and AA cells, so it will default to charging AAA cells at 1000 mA too. However, this is not really all that terrible with cells like Eneloops. It is only a little over 1C charging, and the cells will not get hot since they will terminate on maxV before they get to the point where they start heating up.

(Also note that an indicated 1000 mA on the C9000 is a true rate of 900 mA.)


----------



## tandem

jacknife said:


> I wish there was an indepth one on the C-9000



You've bought a good charger - just read the last several pages of this thread and I think you'll likely read all that there is to know if you just want to get going quickly. If you have the inclination or time to dig deeper now, there is certainly quite a bit of material on cells and chargers you can unearth. Or you can just get going and come back later. 

Even if you do not use all the features to extract the most performance of your cells, you are still going to get excellent bang for your buck out of them before it is time to replace them. Don't worry, be happy!


----------



## jacknife

I have been burning out my eyeballs ( in Search) looking for a chart of charge & discharge rates for AA & AAA batteries, for 1900 Eneloops, If I wanted to program the amounts in. Does one exist ? How do you all come up with the numbers ? I dont think The c-9000 manuel is quite as explicit as I would have made it. If knowing you have a --1900 mah eneloop what is the math?


----------



## pae77

A good general rule of thumb is to simply charge your batteries at 1/2 or .5 C. Which is simply half of the actual capacity of the battery you are charging. This applies for Li-ion as well as NiMH cells. 

So if the capacity of the battery is 2,000 mAh, .5 C is 1,000 mA. And if the charge rate is only off by ~100-200 or so mA it won't hurt anything.

So if you are charging a AAA with a capacity of ~800 mAh, it should ideally be charged at ~400 mA.


----------



## jacknife

Thanks , I am starting with all you Guys --Gals,, help, to figure it out.,, I can see where this c-9000 can be fun charger , but it takes me a few repetitions to get things, So I appreciate the kind help. There was a time when I couldnt hit a Speed Bag as In Boxing ,, but with others help-,,,, YOU SHOULD see me NOW. Thanks for all help. JK


----------



## gggggg

Can you please help me on that 
*Why do batts charged with BC900 deliver 5-10% more capacity compared to the C9000 ??
*
*All capacity measurments were done on the C9000 *(because I read that the BC900 measures different)...


----------



## Yoda4561

Probably because the C9000's end of charge detection is very conservative. This reduces overcharging due to a weak end of charge signal, and likely extends the battery's potential charge cycle lifetime by a significant margin.


----------



## 45/70

Also, in addition to Yoda's comments, when the C9000 says "DONE" the actual charge is not actually finished. The cells are charged enough to be used at this point, however if they are left on the charger for an additional two hours, the charger will continue to charge the cells at a reduced 100mA rate. It is not until this "top off" charge is completed, that cells are fully charged. After the two hours, the charger drops to a ~10mA trickle rate.

Dave


----------



## Anders

Probably why the chargers deliver different results, 45/70:s answer, otherwise "gggg" would have that written, (the charging procedure).

I find it strange, often when a question is asked, the information we need to answer it is not there 

Anders


----------



## lwien

Yoda4561 said:


> Probably because the C9000's end of charge detection is very conservative. This reduces overcharging due to a weak end of charge signal, and likely extends the battery's potential charge cycle lifetime by a significant margin.



Significant margin? Is there any data to back up that claim.


----------



## Yoda4561

Overcharging a battery on a regular basis will kill it pretty quick. It's well studied in lithium ions, and NiMH are not immune to it by a long shot. With lithium ions the difference in charge cycles between ending the charge at 4.2 and 4.21 is something like 20% and seems to go up even more when you end it at 4.18 . If you want hard numbers for how NiMH reacts I don't have them. I have had a few rapid chargers that completely missed the end of charge and didn't have a reliable secondary detection, those were pretty much useless after that. Also a Maha rapid charger that tended to overcharge a bit to get maximum fill, those batteries developed rapid discharge and capacity issues, but they were of that batch of 2500 mAH batteries that all seemed to do that.


----------



## merryman1888

I just received a MH-C9000 from Amazon. I bought it because of good reviews, more functionality and further separation of cell bays than the La Crosse BC-1000. But, it seems from all I'm hearing and seeing for myself that the C9000 is not a true smart charger, in that it won't stop the charge based on if the battery is full, regardless to time, temperature, etc. 

Why isn't there a charger that constantly checks each battery and stops charging based battery status?:thinking:


----------



## Yoda4561

It does stop the charge based on the battery capacity. It uses about half a dozen parameters to detect the correct and safe end of charge for the cell.


----------



## merryman1888

To be a smart charger it should not stop based on temperature unless it's too warm, to prevent damage. It should stop immediately on full capacity, I don't like how it trickle charges after full capacity - I know it, or at least other smart chargers, will charge normally until near full capacity then trickle charge to full then stop when full. 
And the manual of the MH-C9000 states that you should charge at a C that will cause enough heat to stop the charge by the temperature sensor, so you you don't over charge it. So you can't really slow charge a battery! 
I'm guess the La Crosse BC-1000 has the same flaws, but I know you can get a quick check of a battery's remaining mAhs and volts in the BC-1000 which seems not possible in the C9000. 
I'm quite disappointed with the C9000.:ironic:


----------



## Power Me Up

merryman1888 said:


> To be a smart charger it should not stop based on temperature unless it's too warm, to prevent damage. It should stop immediately on full capacity, I don't like how it trickle charges after full capacity - I know it, or at least other smart chargers, will charge normally until near full capacity then trickle charge to full then stop when full.
> And the manual of the MH-C9000 states that you should charge at a C that will cause enough heat to stop the charge by the temperature sensor, so you you don't over charge it. So you can't really slow charge a battery!
> I'm guess the La Crosse BC-1000 has the same flaws, but I know you can get a quick check of a battery's remaining mAhs and volts in the BC-1000 which seems not possible in the C9000.
> I'm quite disappointed with the C9000.:ironic:



The C9000 certainly does qualify as a smart charger - it's a lot smarter than most other chargers since it can measure cell capacity.

The current C9000 stops the main charge when the cell reaches 1.48V - this is a change from the original version to help prevent missed terminations on poor quality cells. Unless you're in a real hurry and want the absolute maximum capacity in your cells in the shortest amount of time, this isn't really a problem. The top off charge gets the cells pretty close to their maximum capacity without putting undue wear on them.

Normally, when charging NiMH cells at fast rates, they will warm up once the cell is full - this isn't normally detected by the temperature rise but rather by a voltage drop (referred to as Negative Delta V) 

Slower charge rates don't lead to a sufficient increase in cell temperature and so there won't be the normal drop in voltage at the end of the charge - this means that charging at slow rates needs to be done at a rate sufficiently low so that the cell isn't damaged by being overcharged. The C9000 isn't designed to slow charge cells unless you're using the Break In function. Slow charging isn't something associated with smart chargers due to the fact that it's normally only a timed charge which can be done by dumb chargers.


----------



## tino_ale

I've been using two MH-C9000 for years now and I don't see how it fails to be a smart charger nor do I find them dissapointing at all.

In fact I've been very happy with them. I only wish they had a dedicated button to cycle through informations instead of a 2 sec cycle through them. Setting the charge between 0.5C and 1C will provide a clear delta-V signal to stop charge reliably with any decent cells.


----------



## merryman1888

Well, IMO the best smart charger would charge a 2000mAh AA @ 200mAhs and stop the charge based on voltage resistance or capacity regardless to temperature. 
I mean isn't it pretty simple to implement something as simple as a voltage and capacity reading to stop the charge?
I think I'm gonna return my MH-C9000 and get the La Crosse BC-1000 I like that it can do a quick battery status reading, something so simple should have been featured in the C9000. Although, I know I'll be losing some features of the C9000.


----------



## blgentry

merryman1888 said:


> Well, IMO the best smart charger would charge a 2000mAh AA @ 200mAhs and stop the charge based on voltage resistance or capacity regardless to temperature.



I think you're confused. The C9000 stops based on Negative Delta V. That's a Voltage drop that indicates a fully charged cell. Temperature is only used a an EMERGENCY stop mechanism.

Further, charging a 2000 mAh cell at 200 mA isn't a good everyday charging rate. Slower is not better. Do some research and you'll see all the reasons why.



> I mean isn't it pretty simple to implement something as simple as a voltage and capacity reading to stop the charge?



You're confused again. "Capacity reading" does not exist as something you can quickly measure in a NiMh cell. To measure capacity, you have to discharge the battery. So there's no way to measure this while charging. You can only use Negative Delta V, or temperature, or time. As for Voltage, the C9000 reads Voltage as it is charging, so it's easy to see the Voltage each cell being charged.



> I think I'm gonna return my MH-C9000 and get the La Crosse BC-1000 I like that it can do a quick battery status reading, something so simple should have been featured in the C9000. Although, I know I'll be losing some features of the C9000.



What status reading are you referring to? You probably mean how much charge has been put INTO the cell. That is not an indication of capacity. It only tells you how much energy the charger has spent charging the cell. Return your C9000 if it makes you feel better, but you're not getting anything from the BC-1000 that the C9000 can't do.

Brian.


----------



## Power Me Up

merryman1888 said:


> Well, IMO the best smart charger would charge a 2000mAh AA @ 200mAhs and stop the charge based on voltage resistance or capacity regardless to temperature.
> I mean isn't it pretty simple to implement something as simple as a voltage and capacity reading to stop the charge?



It's pretty easy to put a slow charge into a cell and deliver a fixed amount of charge into it - that's what dumb timer based chargers do. Although you can have a dumb charger put a fixed charge in each time, what happens when you're wanting to charge a cell that is only half empty? A dumb charger just wastes time and energy continuing to charge a cell after it's full. 

Resistance isn't an indicator of charge state on NiMH cells, and voltage isn't a good indicator at the low charge rates that you're wanting.



merryman1888 said:


> I think I'm gonna return my MH-C9000 and get the La Crosse BC-1000 I like that it can do a quick battery status reading, something so simple should have been featured in the C9000. Although, I know I'll be losing some features of the C9000.



I'm by no means an expert on the BC-1000, but I'm pretty sure that it doesn't have any features that the C9000 doesn't have. I'm not sure what you're meaning by "quick battery status reading?"


----------



## merryman1888

blgentry said:


> I think you're confused. The C9000 stops based on Negative Delta V. That's a Voltage drop that indicates a fully charged cell. Temperature is only used a an EMERGENCY stop mechanism.



I know, but I thought there was a more adequate way of determining "fullness". And Maha states in the manual that if you don't set charge rate high enough to cause enough heat to trip the temp. sensor then you will over charge you battery. So the temp. sensor seems to be more than a emergency stop. 



blgentry said:


> Further, charging a 2000 mAh cell at 200 mA isn't a good everyday charging rate. Slower is not better. Do some research and you'll see all the reasons why.



Yes, I have seen many people say that ni-mh likes relative faster charges vs. too slow(which I think is true) due to the internal chemistry, but risky reasons not to charge slow(in the event that one may charge slow for unique preference) is the fact of these "smart" chargers rely heat indication to stop the charge - as Maha confirmed. 





blgentry said:


> You're confused again. "Capacity reading" does not exist as something you can quickly measure in a NiMh cell. To measure capacity, you have to discharge the battery. So there's no way to measure this while charging. You can only use Negative Delta V, or temperature, or time. As for Voltage, the C9000 reads Voltage as it is charging, so it's easy to see the Voltage each cell being charged.



I was just thinking that there was a way to indicate present "fullness" like a battery gauge would, but I guess that's all determined from voltage readings which is how done already. 




blgentry said:


> What status reading are you referring to? You probably mean how much charge has been put INTO the cell. That is not an indication of capacity. It only tells you how much energy the charger has spent charging the cell. Return your C9000 if it makes you feel better, but you're not getting anything from the BC-1000 that the C9000 can't do.
> Brian.



No, I was referring a quick battery status(remaining battery "fullness" and present volts) check before charging, like I could just pop in one battery after the other to check each batteries present remaining amp/volts. So I could allocate batteries of similar remaining amps/volts. Yes, all the BC chargers series have that very useful feature.


----------



## Verndog

blgentry said:


> What status reading are you referring to? You probably mean how much charge has been put INTO the cell. That is not an indication of capacity. It only tells you how much energy the charger has spent charging the cell.
> Brian.



It is also a handy tool to use when you are just charging or cycling. If there is a sudden change of how many mah the cell accepted in a cycle, you now have another tool to catch suspect cells and perform further testing.


----------



## blgentry

This has become too long to respond point by point. Merryman, you seem to have drawn some strange conclusions, at least according to what I know. Here's the deal:

1. Maha does NOT USE TEMPERATURE as a primary way to end charging. It uses Negative Delta V. This is a backwards (negative) change in Voltage that tells the charger that the cell is finished charging.
2. You probably read a passage in the C9000 manual that warns against "missed terminations". That happens when the charge rate is TOO LOW. The Negative Delta V could be missed at super low rates. Temperature is used "simultaneously", which means that if it gets too hot, it ends the charge. It does not "need" for the cell to get hot to stop charging. It's a secondary method.
3. Voltage is NOT AN INDICATION of battery fullness for NiMh. It's a sort of rough guide under some conditions, but it's no where near a guarantee of state of charge (fullness).
4. The Lacrosse BC series chargers show you battery Voltage when you first insert them. This does NOT show you battery fullness. It's a decent guess, but it's not accurate at all.
5. As everyone here will tell you, the only way to know the capacity of an NiMh cell is to discharge it and measure the capacity.

In conclusion: The C9000 *is* a smart charger and does not need temperature to work correctly. Slow charging is actually more risky (missed terminations) than faster charging. Voltage readings don't tell you how full your cells are. The BC series chargers don't have a magic capacity tester. 

I don't think I'll further respond to this subject. If you still want to get a different charger, so be it.

Brian.


----------



## Viking

merryman1888 said:


> No, I was referring a quick battery status(remaining battery "fullness" and present volts) check before charging, like I could just pop in one battery after the other to check each batteries present remaining amp/volts. So I could allocate batteries of similar remaining amps/volts. Yes, all the BC chargers series have that very useful feature.



Unfortunately, there is no charger ( or any other device for that matter ) there is able to show the capacity before a discharge.


However there is probably one charger on the market ( Ansmann Energy XC3000 )
, there is able to give a qualified guess , pretty much the same way the ZTS battery tester does. 
This is a much more reliable way to measure the capacity , than just by reading the volts.

http://www.youtube.com/watch?v=0R99Wa2FWlU

( The Ansmann Energy XC3000 will be shown after about 35 seconds into the video )


----------



## march.brown

merryman1888 said:


> Well, IMO the best smart charger would charge a 2000mAh AA @ 200mAhs and stop the charge based on voltage resistance or capacity regardless to temperature.


I guess you are entitled to your own opinion , even if it is different to the vast majority of other users and manufacturers.
. 


> I mean isn't it pretty simple to implement something as simple as a voltage and capacity reading to stop the charge?


As has been said many times , the only way to tell the battery capacity of a NiMh cell is to fully charge it then fully discharge it whilst monitoring the mAh capacity ... There is no other way with a NiMh ... With Li-Ions , on the other hand , open circuit voltage on a rested cell gives a pretty good estimate of the capacity (as a percentage of full charge) ... It is just a shame that there is no way to accurately guess the capacity remaining in a NiMh cell.
.


> I think I'm gonna return my MH-C9000 and get the La Crosse BC-1000 I like that it can do a quick battery status reading, something so simple should have been featured in the C9000. Although, I know I'll be losing some features of the C9000.


After you have had your new charger for a while , you will realise that it works in much the same way as the C9000 ... Just do what you think is best for your own method of charging , based on all your charging experience over the years.

I will stick with my C9000 and use 1000mA for my AA Eneloops and 400mA for my AAA Eneloops ... I can see no point in risking a very low charge rate that lasts for many hours ... I really like the fact that the C9000 tops up the AA cells for two hours at 100mA after the initial 1000mA charge ... The only thing that I do different on AAA cells is to take the cells off the top up charge after one hour ... But that's my own personal choice when charging the AAA cells at 400mA.

Anyway , good luck in your new choice of charger ... It is not a bad choice.
.


----------



## robcope

Recieved mine yesterday and have been playing with it all night here at work. I really like it so far. Unfortunately all I have been able to do is discharge one set of eneloop AA's and one set of eneloop AAA's. I was a bit worried after reading all the reviews about how complicated it is. No way, this thing is a breeze. Can't wait to get home this morning and start the break in on these disharged cells. I love the screen, so easy to read. Spent most of the past two nights reading about it in the forums and I think it will more than serve my needs.


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## merryman1888

Oh, then we are not on the same page, I was saying "fullness" as in remaining milliamp hours(mahs) 

Well, then the thing I like about the BCs is that they can give, inaccuate as it is, a status reading of remaining mahs in any given cell. Which is useful if you want to organize batteries based on relative remaining mahs, or just for curiosity want to check relative remaining mahs in a battery that's been stored for months. Maha could've added this, it's better than not having any indication of remaining mahs. 
I also wish Maha would brought down the default charge rate to like 500ma, which is .25C for a typical AA Eneloop, but it's better than having a high default charge rate for a typical AAA.


----------



## Power Me Up

merryman1888 said:


> Oh, then we are not on the same page, I was saying "fullness" as in remaining milliamp hours(mahs)
> 
> Well, then the thing I like about the BCs is that they can give, inaccuate as it is, a status reading of remaining mahs in any given cell. Which is useful if you want to organize batteries based on relative remaining mahs, or just for curiosity want to check relative remaining mahs in a battery that's been stored for months. Maha could've added this, it's better than not having any indication of remaining mahs.
> I also wish Maha would brought down the default charge rate to like 500ma, which is .25C for a typical AA Eneloop, but it's better than having a high default charge rate for a typical AAA.



I'm really not sure where you're getting this idea that the BC chargers can give you a remaining capacity without doing a discharge first. A number of us have tried to correct you on this, but you seem to be intent on believing what you want to believe...

With regard to charging at lower rates, perhaps you should read the following thread:
http://www.candlepowerforums.com/vb...-NiMH-at-high-and-low-rates-what-can-go-wrong


----------



## march.brown

merryman1888 said:


> I also wish Maha would brought down the default charge rate to like 500ma, which is .25C for a typical AA Eneloop, but it's better than having a high default charge rate for a typical AAA.


Most of us prefer the 1000mA charge rate as we have , in general , more AA's than AAA's and for me the 500mA is higher than the 400mA that I always use for my AAA's ... If the default charge rate was 500mA , I would have to alter the charge rate every time I used the charger.

Luckily it defaults to 1000mA which means that I only occasionally have to alter the rate to 400mA for my few AAA Eneloops.

The C9000 might not suit everyone but luckily it suits the vast majority of users , which is why it is rated as one of the very best available and one which many users aspire to ... It is possible that you just might be one of the very small minority who prefer to use a different make of charger ... Luckily there are lots to choose from and unfortunately for me I tried many other delta-V chargers first ... If only I had bought the C9000 one first , I could have saved myself quite a bit of money.

I'm sure you will eventually find a charger that will suit your individual needs ... If your preference is for a long charge period at a low charge current , there are lots of cheap chargers that will do the job ... That would also save you a lot of money.

Good Luck.
.


----------



## shadowjk

I have both Lacrosse/etc BC-series chargers and Maha C-9000. I would say that I trust the C-9000 alot more than the others.

BC-* only has 2 temperature sensors, but 4 battery bays. I have had situations where a battery in bay #4 has started overheating, but the battery in bay #3 had already finished charging, and was acting like a heatsink for the shared temperature sensor, the charger didn't notice overheating until it was too late, and the plastic of the charger melted enough that the battery terminals moved apart and broke the connection.

As for NIMH charging, the difficulty in detecting how full or empty a cell is, at any stage, whether cell is open circuit (not in use), discharging, or charging, makes charging pretty complicated. in general, there are 2 primary charging strategies. 
* Slow charging with timer
* Fast charging with 3-4 algorithms being run simultaneously to detect full battery

The downside of slow charging is that it takes longer time. It relies in the battery being able to absorb some overcharging at low rates without sustaining too much damage. It's worth noting that the battery manufacturers like Sanyo don't use slow charging when they test how many cycles the batteries can be used. If a full cell is inserted into a slow charger, the amount of overcharge might be too much for the cell to handle, and it will vent gas, and its performance will be permanently degraded. The upside of slow charging is that it's cheap and simple to make charger.

Fast charging faces the challenge of detecting when a battery is full. 
The first method is called negative delta-V. This means a microprocessor constantly monitors the charge voltage, when the charge voltage starts *dropping*, the charge is complete. This voltage drop is sometimes very small, and the slower the charge rate, the smaller the drop will be, or it wont be present at all. The older and more worn a cell gets, the smaller the voltage drop gets.
The second, back up method is temperature. As the battery gets full, the energy inserted in the battery gets converted to heat, which means the cell will heat up. Chargers may attempt to detect the sudden acceleration in temperature rise, in addition to a upper temperature cutoff. The older and more worn a battery is, the more energy gets converted to heat even during charge, before the battery is full.
Thirdly, you can have a timer cutoff. If the charge goes on for too long without either "Cell is full" criteria triggering, you stop the charge.

BC-* and Maha C-9000 both use negative delta-V as the primary method. 

For the secondary method, BC-* has one temperature sensor for bays 1 and 2, and another sensor for 3 and4. On overtemp, the charger pauses charging, but resumes later. C-9000 has one temperature sensor per battery bay, 4 in total.

As tertiary method, both C-9000 and BC-* have capacity cutoffs at 3000mAh (IIRC).

The C-9000 additionally has a fourth method, an upper voltage limit at 1.48V.


In practice, the C-9000 detects end of charge at an earlier point than BC-*. The C-9000, however, after this earlier end of charge detection, enters a "top-off" mode where it acts like a slow-charger for 2 hours. After BC-* terminates, it enters a trickle charging mode. The rate of current varies, typically starting out high and then dropping off over time.


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## merryman1888

@*shadowjk* One of the guys at La Crosse said he has the BC-700 and the BC-1000, and said both of them have a quick battery status reader - estimating of a battery's "fullness" (as a percentage of full charge). Is this true of the BC-* chargers you have? 
I know given the nature of determination it is not accurate, but it's more useful than not have any indication: before a charge or just for curiosity.

I say "fullness" because its confusing to say capacity, when capacity only means how much a battery can hold, not milliamp hours remaining, in any given cell.

P.S. I don't know why the C9000 doesn't at least give a reading of battery's volts when inserted.


----------



## Mr Happy

merryman1888 said:


> @*shadowjk* One of the guys at La Crosse said he has the BC-700 and the BC-1000, and said both of them have a quick battery status reader - estimating of a battery's "fullness" (as a percentage of full charge). Is this true of the BC-* chargers you have?
> I know given the nature of determination it is not accurate, but it's more useful than not have any indication: before a charge or just for curiosity.
> 
> I say "fullness" because its confusing to say capacity, when capacity only means how much a battery can hold, not milliamp hours remaining, in any given cell.
> 
> P.S. I don't know why the C9000 doesn't at least give a reading of battery's volts when inserted.



There is no good way of giving a quick reading of an NiMH battery percentage of full charge. The only possible way to do it is to apply a load and measure the cell voltage--but the accuracy of this method is very poor and unreliable due to variations between different batteries. To the best of my knowledge the LaCrosse chargers do not have this feature in any case. You are being misled.

The C9000 does not give a reading of the battery's volts when inserted, but if you want to find out just start a discharge going. The voltage reading during discharge will give you a much more meaningful result (see above).

As to the comments about measuring temperature, the temperature is in fact the _best_ way to detect the end of charge condition in a battery. Good chargers should measure the cell temperature and use it. Look at the graph below in the thread that someone pointed you towards in an earlier post:







Do you see how the temperature starts rising sharply when the cell is fully charged? This is as perfect an indication of the cell being fully charged as you could hope for. A charger would be foolish to ignore this information.


----------



## march.brown

merryman1888 said:


> I don't know why the C9000 doesn't at least give a reading of battery's volts when inserted.


It looks as though an accurate digital voltmeter would be useful for your voltage checks ... A decent DMM will generally give a more accurate reading than a meter incorporated into a battery charger ... My 6000 count Fluke 175 reads 5.000V when checked against my 5.00V Precision Voltage Reference Source , which is actually certified as 5.0002 volts at 72F ... My very cheap meter (about £5) reads 5.00V and is certainly good enough for any battery work ... Also , being a 2000 count meter , it wil read 1.***V on voltages less than two volts which makes it ideal for AA and AAA batteries ... My 5.00V reference was only $20.15 including USPS First Class Mail to the UK from America ... This is perfect for checking any meter for accuracy ... I wouldn't like to be without this reference.
.


----------



## Verndog

Mr Happy said:


> There is no good way of giving a quick reading of an NiMH battery percentage of full charge.



I'll disagree with this. Checking resting voltage and knowing your cells you can easily get an idea between full , 1/2 used, or dead and that is all most people need to know when they throw a questionable cell in. (1.37v and up=full , 1.26= about 50% 1.2v = dead. You can prove these numbers to "your" batteries by checking voltage then discharging to see what really was in there. Exact doesn't matter, and the voltage display is a handy feature that all my chargers have (Accupower, LaCrosse, and Team Checkpoint hobby chargers). Yes, a MM can come in handy also, but with these chargers you dont "need" to go fetch one.


----------



## Mr Happy

Verndog said:


> I'll disagree with this. Checking resting voltage and knowing your cells you can easily get an idea between full , 1/2 used, or dead and that is all most people need to know when they throw a questionable cell in. (1.37v and up=full , 1.26= about 50% 1.2v = dead. You can prove these numbers to "your" batteries by checking voltage then discharging to see what really was in there. Exact doesn't matter, and the voltage display is a handy feature that all my chargers have (Accupower, LaCrosse, and Team Checkpoint hobby chargers). Yes, a MM can come in handy also, but with these chargers you dont "need" to go fetch one.



You're right, and if you know your batteries that works perfectly.

What I mean is that there is no "good" way, in general, in a consumer product, for any random unknown NiMH cell that might be new or old, one brand or another, of giving more than an approximate estimate of remaining charge. Unlike, say, an alkaline cell where a battery tester can usually give a very reasonable estimate.


----------



## Verndog

One other useful check of voltage is if your are running a multi cell light (or any device), getting in to the habit of checking all cells voltage before recharging and looking for weak cells. If your batteries are the same type/mah, and near the same age, then they should be close in voltage when discharged and checking is another tool to use. If you have one that is considerably lower, you can further investigate that cell to help keep all cells in top reliable condition.


----------



## merryman1888

Its quite cumbersome to start a discharge, just to get a reading of volts, anyway I do acknowledge the C9000 to be one of the best chargers and have decided to keep it. 
I was curious why after the C9000 finished a discharge of 4 new regular Eneloop AA batteries at 100ma it displayed 350mah 480mah 680mah and 450mah? I thought it would drain them completely. 
Now regarding the charge current of the C9000 doesn't it always do a pulse charge fluctuation of like 1000ma to 100ma regarless to what mode or settings you use?


----------



## tatasal

merryman1888 said:


> Its quite cumbersome to start a discharge, just to get a reading of volts, anyway I do acknowledge the C9000 to be one of the best chargers and have decided to keep it.
> I was curious why after the C9000 finished a discharge of 4 new regular Eneloop AA batteries at 100ma it displayed 350mah 480mah 680mah and 450mah? I thought it would drain them completely.
> Now regarding the charge current of the C9000 doesn't it always do a pulse charge fluctuation of like 1000ma to 100ma regarless to what mode or settings you use?



The four figures you mentioned are the individual discharge capacities of the cells you discharged at 100ma.


----------



## merryman1888

tatasal said:


> The four figures you mentioned are the individual discharge capacities of the cells you discharged at 100ma.


Meaning those figures are how much estimated mahs was remaining before the discharge or how much mas was needed to discharge the cells to completely drain them? William


----------



## merryman1888

Mr Happy said:


> As to the comments about measuring temperature, the temperature is in fact the _best_ way to detect the end of charge condition in a battery. Good chargers should measure the cell temperature and use it. Look at the graph below in the thread that someone pointed you towards in an earlier post:
> 
> 
> 
> 
> 
> 
> Do you see how the temperature starts rising sharply when the cell is fully charged? This is as perfect an indication of the cell being fully charged as you could hope for. A charger would be foolish to ignore this information.




Well, it should terminate charge shortly after the plateau in voltage: an indication of no increasing voltage over a given segment of time. Although, the temperature would be harmful even after that method of termination, but I would like to charge an AA cell @ 200ma and therefore decreasing heat, yet hopefully it would still have the same basic voltage profile as the Eneloop @ 400ma in your graph. 

As what I think Uk Caver is saying... 


uk_caver said:


> As long as the measurement period is long enough to prevent spurious early termination, 0dV is a pretty good backup termination method to -dV when smart-charging NiMH at low rates.
> Charging ~4AH single cells and 3-cell packs at ~800mA on a homebuilt charger, short-period -dV generally triggers termination, but a 0dV based on a longer detection period sometimes cuts in first.
> Some of the time, if a 0dV signal had been ignored, -dV would have triggered a little later, but pretty much all the time, if a short-period -dV had been ignored, then a longer-period 0dV cutoff would have happened reasonably soon (unless voltage were to suddenly start rising again).


----------



## tatasal

merryman1888 said:


> Meaning those figures are how much estimated mahs was remaining before the discharge or how much mas was needed to discharge the cells to completely drain them? William



It was the remaining discharge capacities of the cells at the time it was discharged. If the cell was fully-charged before the discharge, then that tells you the health of your cells as compared to its original minimum capacity of 1800mAh.


----------



## Mr Happy

merryman1888 said:


> Well, it should terminate charge shortly after the plateau in voltage: an indication of no increasing voltage over a given segment of time.


The trouble with that strategy is that in some cases there can be a voltage plateau in the middle of charging, long before the cell is fully charged. This can cause premature termination. The actual dip in voltage (the minus delta-V signal) is the most certain indication that the cell is full.



> Although, the temperature would be harmful even after that method of termination


The temperatures in that graph are not really harmful at all. One normally would not worry about temperatures up to 45 or 50 Celsius at the end of charging. Such temperatures routinely happen if you charge at the recommended 0.5C to 1.0C rate with minus delta-V termination.


----------



## rwharold

I am relatively new to this forum. I have read many of the posts, but cannot find the answer to my question. I've heard that the Maha C9000 rips the battery covering when removing the cell. Is there anyway to prevent this from happening? I am considering the purchase of the C9000. Is it still the best choice? I've read some negative reviews on Amazon.


----------



## Mr Happy

rwharold said:


> I am relatively new to this forum. I have read many of the posts, but cannot find the answer to my question. I've heard that the Maha C9000 rips the battery covering when removing the cell. Is there anyway to prevent this from happening? I am considering the purchase of the C9000. Is it still the best choice? I've read some negative reviews on Amazon.



If you lift out the cell at the positive end first and negative end last you should have no trouble with damaged cell coverings.

In my opinion, if you want the most complete set of features and capabilities the C9000 is the best choice among consumer chargers. It has certain limitations, but the good features outweigh the bad. Having owned one for years I don't pay much attention to negative reviews any more.


----------



## Russel

merryman1888 said:


> [...]I was curious why after the C9000 finished a discharge of 4 new regular Eneloop AA batteries at 100ma it displayed 350mah 480mah 680mah and 450mah? I thought it would drain them completely.



New Eneloop AA cells are not fully charged when shipped for sales. The new Eneloops that I've discharged after first opening a new package of them usually indicate about 600 mAh. Some more, some less. The numbers that you posted are what was avalible in the cells when your C9000 fully discharged them.



merryman1888 said:


> Now regarding the charge current of the C9000 doesn't it always do a pulse charge fluctuation of like 1000ma to 100ma regarless to what mode or settings you use?



The MH-C9000 charges by pulsing a 2000 mA charge current. So, for a 1000 mA average charge current, it would supply a 2000 mA charge current at a 50% duty cycle. For a 500mA charge current it is pulsed with a 25% duty cycle.

Discharge current is a 1000 mA and pulsed as required. For example, discharging at 100 mA such as you did with your new Eneloops the 1000 mA discharge current is pulsed at a 10% duty cycle.

More details and fancy scope captures:
http://www.candlepowerforums.com/vb...age-measured&p=3581455&viewfull=1#post3581455


----------



## Verndog

I read a report saying the C9000 pulsed for 2 seconds on then less then 1/2 second pause. If that is true then it would not be as simple as doubling the amperage.

Edit...well I guess this trumps that info...So it doesn't vary the amperage just the length of pulse??


----------



## Russel

Verndog said:


> [...]Edit...well I guess this trumps that info...So it doesn't vary the amperage just the length of pulse??



Correct. The pulse width is different for each (average) current setting. The current of the charging pulse is always 2000 mA, just of different pulse width, depending on the current setting on the display.


----------



## Mr Happy

Russel said:


> Correct. The pulse width is different for each (average) current setting. The current of the charging pulse is always 2000 mA, just of different pulse width, depending on the current setting on the display.



And just for a slight wrinkle, there is always an off time even when charging at 2000 mA. So for example, at 2000 mA charge rate there is approximately a 1.8 s on time and 0.2 s off time for an average charge current of about 1800 mA. It turns out that all displayed charge currents need to be multiplied by 0.9 to get the actual current.


----------



## Russel

Mr Happy said:


> And just for a slight wrinkle, there is always an off time even when charging at 2000 mA. So for example, at 2000 mA charge rate there is approximately a 1.8 s on time and 0.2 s off time for an average charge current of about 1800 mA. It turns out that all displayed charge currents need to be multiplied by 0.9 to get the actual current.



That's correct. Here is an illustration. The MH-C9000 charging at 2000 mA.


----------



## SilverFox

Hello Rwharold,

Welcome to CPF.

The damage to the shrink wrap involves AAA cells that have it extended over the bottom knuckle of the cell. I don't believe there are any problems with AA cells.

Inspect your AAA cells to see if this will be a problem for you. If you see the shrink wrap extending over the bottom knuckle you can trim it back and avoid any issues.

There are shortcomings with every charger, but the C9000 is very good. I have two of them and they have been in constant use since they first came out. 

Tom


----------



## rwharold

SilverFox said:


> I was reading the information on the C9000 (Wizard 1) charger over at Thomas Distributing. There were several things listed that seemed different to me. One was a 15 cycle capability, another was the Break In mode was referred to as going through 4 cycles and ending with a medium charge.
> 
> I believe these differences came from pre-production notes, but then I had the wild idea that perhaps Maha has slipped some changes in under our noses.
> 
> I prefer the Wizard 1 over the BC-900, so I recently acquired a second C9000 charger.
> 
> I have noticed some differences…
> 
> I was using the Refresh/Analyze mode.
> 
> My original charger would charge first, rest for an hour, discharge, rest, then charge back up. During the rest period between charging and discharging I would see the voltage gradually settle down from the peak charge voltage.
> 
> My newer charger does this differently. It still follows the same sequence, but the rest time between charging and discharging is now two hours, and the voltage holds steady. It is as if there is now a top off charge being applied during the rest period.
> 
> The next thing I noticed was that while charging a 9000 mAh D cell, external to the unit, it stopped charging at 4000 mAh. We have seen AA cells that have missed their charge termination signal go for longer than that.
> 
> Finally, I took my Tenergy cells that missed the end of charge termination on both the C9000 and the BC-900 when charging at 500 mA, discharged them, then charged them in this latest C9000 to see what would happen. All the cells terminated properly.
> 
> Does anyone else have a recent C9000? Have you noticed any other changes in it?
> 
> My original one was purchased during the pre-sale. This last one came last week.
> 
> Tom



Hi SilverFox,

I hope you are still monitoring this thread. I just purchased a new Maha C9000 and recieved it yesterday. The production lot number is 0L0HA. There has been one MAJOR change in this version. It no longer makes any sound what-so-ever. It's completely silent when charging. I have two questions about the break-in setting. First, I'm running the break-in cycle without a discharge first on a brand new set of AA 2000 mA 1500 cycle LSD Eneloop cells. Am I making a mistake by not discharging first? Second question is, after the last break-in charge cycle, does the charger still give a two hour top-off charge cycle? Or does the top-off charge work only after the regular CHARGE setting? Thanks for your assistance.


----------



## SilverFox

Hello Rwharold,

Welcome to CPF.

The idea of discharging before running a break in has to do with limiting the amount of overcharge the cell receives. Theoretically the charge rate is low enough that no damage should occur, but those of us who are a "bit particular" about our cells go through the extra step just to make sure.

The top off charge is not a part of the break in algorithm.

Tom


----------



## rwharold

SilverFox said:


> Hello Rwharold,
> 
> Welcome to CPF.
> 
> The idea of discharging before running a break in has to do with limiting the amount of overcharge the cell receives. Theoretically the charge rate is low enough that no damage should occur, but those of us who are a "bit particular" about our cells go through the extra step just to make sure.
> 
> The top off charge is not a part of the break in algorithm.
> 
> Tom



Thanks Tom. 

I thought I would share on this forum the review that I wrote about the Maha C9000 on the Amazon website. Perhaps some readers may have some comments.

"5.0 out of 5 stars *Best all around charger. Improved version! Better than La Crosse.*, February 16, 2013 
By 
*Richard W. Harold* (Reston, VA) - See all my reviews
(REAL NAME) 




*This review is from: PowerEx MH-C9000 WizardOne Charger-Analyzer (Electronics)* 
I did a lot of research on AA/AAA battery chargers before I made this purchase. I read NLee the Engineer's review and several reviews on Candle Power Forums to get the very best advice. I narrowed down the choice between the La Crosse BC 700/1000 and The Maha Powerx C9000 chargers. Almost all the reviews that I read recommended the Maha Powerex C9000 over the La Crosse models. I had questions about each model so I tried to telephone Technical Support at each company. I had no luck what-so-ever with the La Crosse Company. The telephone was answered by a recording saying that Technical Support was busy and asked to leave a message and they would call me back. I tried calling La Crosse three separate times on different days and always got the same recording and NEVER recieved a call back. Then, I tried to call the Maha Energy Company and got through to a live Technical Support person on the very first attempt. I called them several times because I kept having new questions. I got through each time with no delays or recordings. The other deciding factors were the comments about the La Crosse failure rate and having only a one year warranty. The Maha Powerex C9000 comes with a three year warranty and has a more rugged design! After weeks of research, I finally decided to purchase the Maha Powerex C9000. It just arrived yesterday. The first thing I noticed is that it is not as "HUGE" as some reviewers have commented. It's just the right size leaving plenty of room between the batteries for effecient cooling. I first tried to do a Break-In (charge/discharge/charge) cycle on some discharged eight year old Radio Shack 2000 mA NiMH batteries. The charger just would not charge or break them in. The screen went blank and the display went from Break-In back to Charge with nothing happening. I got the same result on all 4 cells. I immediately called Maha and the Technical Support agent told me that my batteries were bad and could not be recharged or broken in by the C9000. The strange thing is that the batteries are used in my fire/police radio scanner which has a 9 V 300 mA power supply/charger which continues to charge my batteries without any problems. I guess there must be some type of defect in the batteries, but they still work! At the same time that I made my purchase of of the C9000, I also bought a 10 pack of the highly rated, new 1500 cycle 2000 mA LSD Sanyo Eneloop AA batteries. After reading the well written instructions on the C9000, I decided to run the new Eneloops through the Break-in cycle as recommended for new batteries. IMPORTANT NOTE: Be sure to FIRST run a DISCHARGE cycle at 500 mA BEFORE a Break-in cycle to avoid over charging 2000 mAH batteries. The manual does NOT mention this critical step, but it's necessary according to the experts at Candle Power Forums and NLee the Engineer. The first thing that I noticed was how very easy it was to program the four separate slots of the charger. Just a few button presses to choose the 2000 mA rating of the Eneloops and that was it. I repeated the process for each slot. Definitely not as hard to program as some reviewers have stated. One thing to remember is that even a brief electrical power interruption will cause the charger to reset to the defaut setting of Charge at 1000 mA. So it's highly recommended to plug the charger into a UPS to prevent any resetting of the charger. I checked the bottom of my charger and noticed that I have production lot number 0L0HA. This must be the very latest version because I noticed a major change in the charger's operation. It no longer makes a high pitched sound when charging as some reviewers have stated. It's totally silent! Yes, the display is bright which makes it easy to read and it makes a good night light for my bedroom. I am thoroughly satisfied with my decision to purchase the C9000. It's a remarakable, well built, and effecient charger. I would highly recommend it to anyone looking to purchase the very BEST charger on the market. "


----------



## Russel

rwharold said:


> [...]The first thing that I noticed was how very easy it was to program the four separate slots of the charger. Just a few button presses to choose the 2000 mA rating of the Eneloops and that was it. I repeated the process for each slot. Definitely not as hard to program as some reviewers have stated. One thing to remember is that even a brief electrical power interruption will cause the charger to reset to the defaut setting of Charge at 1000 mA. So it's highly recommended to plug the charger into a UPS to prevent any resetting of the charger.[...]



The default charge rate of 1000 mA is fine for charging Eneloop AA cells. You don't need to press any buttons, just install the batteries and they will start charging at the default rate. Because the default rate is fine for Eneloop AA cells, you don't really need to worry about powering the charger from a UPS. If you have a power interuption, the charger will start again at the default rate and charge the cells normally. It could be a concern when charging smaller cells such as AAA cells with a capacity of about 800 mAh.


----------



## rwharold

Russel said:


> The default charge rate of 1000 mA is fine for charging Eneloop AA cells. You don't need to press any buttons, just install the batteries and they will start charging at the default rate. Because the default rate is fine for Eneloop AA cells, you don't really need to worry about powering the charger from a UPS. If you have a power interuption, the charger will start again at the default rate and charge the cells normally. It could be a concern when charging smaller cells such as AAA cells with a capacity of about 800 mAh.



Thanks Russel for your comments. 

I agree completely with you about Eneloop AA 2000 mA cells. I was just trying to caution users just in the case they were using lower rated AAA cells or some other function (other than Charge) in the C9000. Better safe than sorry!


----------



## InHisName

rwharold said:


> I first tried to do a Break-In (charge/discharge/charge) cycle on some discharged eight year old Radio Shack 2000 mA NiMH batteries. The charger just would not charge or break them in. The screen went blank and the display went from Break-In back to Charge with nothing happening. I got the same result on all 4 cells. I immediately called Maha and the Technical Support agent told me that my batteries were bad and could not be recharged or broken in by the C9000. The strange thing is that the batteries are used in my fire/police radio scanner which has a 9 V 300 mA power supply/charger which continues to charge my batteries without any problems. I guess there must be some type of defect in the batteries, but they still work!



Keep using those Radio Shack batteries as long as the run time is not annoying you. Most here consider them junk cells at this point. When the run time is too short for you, toss them into the recyle bin and use 4 of the eneloops.

The RS batts have increase their internal resistance so much that the C9000 cannot charge them with the 2 amp pulses it uses. The 300ma current from the 9v charger is still somewhat effective in 'snealking' the charges past the higher internal resistance. Keep that charger, in case you need other cells that deterioated to junk status. I have some Duraloops that have reached that status. All NiMH wll approach junk status as they age and wear out. 

The C9000 charges the cells and displays a voltage related to the internal resistance. For new eneloop AAs, I've seen in low 1.50's. When it sees 2.13 it seems to decide to call it HIGH and refuse to charge anymore. If the number gets to be at 2.87 it will not even display it anymore and just blank out the screen and start from begining like you just plugged in the battery to start charging it. I call it MOST HIGH. Seems that those Radio Shack batts are in the MOST HIGH category.


----------



## rwharold

InHisName said:


> Keep using those Radio Shack batteries as long as the run time is not annoying you. Most here consider them junk cells at this point. When the run time is too short for you, toss them into the recyle bin and use 4 of the eneloops.
> 
> The RS batts have increase their internal resistance so much that the C9000 cannot charge them with the 2 amp pulses it uses. The 300ma current from the 9v charger is still somewhat effective in 'snealking' the charges past the higher internal resistance. Keep that charger, in case you need other cells that deterioated to junk status. I have some Duraloops that have reached that status. All NiMH wll approach junk status as they age and wear out.
> 
> The C9000 charges the cells and displays a voltage related to the internal resistance. For new eneloop AAs, I've seen in low 1.50's. When it sees 2.13 it seems to decide to call it HIGH and refuse to charge anymore. If the number gets to be at 2.87 it will not even display it anymore and just blank out the screen and start from begining like you just plugged in the battery to start charging it. I call it MOST HIGH. Seems that those Radio Shack batts are in the MOST HIGH category.



Thanks for your comments. Now I have a clearer understanding of what's going on! You did a MUCH better job of explaing this to me than the Maha Technical Service technician did.


----------



## Mr Happy

rwharold said:


> Thanks for your comments. Now I have a clearer understanding of what's going on! You did a MUCH better job of explaing this to me than the Maha Technical Service technician did.



Mainly the C9000 is trying to avoid charging alkaline batteries that may have been accidentally (or deliberately!) inserted into the charger. Attempting to charge an alkaline battery would produce a horrible mess and would ruin the charger, so it plays it safe and refuses to charge any battery that looks like an alkaline battery.


----------



## shadowjk

Those batteries that show "HIGH" on C9000, or that cause the display to go black and then reset, are also no good for use with high drain / high power devices.. Still usable for radio receivers and other low drain stuff though,


----------



## rwharold

shadowjk said:


> Those batteries that show "HIGH" on C9000, or that cause the display to go black and then reset, are also no good for use with high drain / high power devices.. Still usable for radio receivers and other low drain stuff though,



Thanks for your reply. Fortunately as you said, I'm using these very old Radio Shack MiMH 2000 mA batteries in a fire/police radio scanner. I can still charge them using the radio's 9V 300 mA power supply/charger. I listen to the scanner all day and the batteries still last about 9 hours! Remarkable for a "bad" battery! My only regret is that I can't use my brand new Maha C9000 charger, but I now understand what's going on. When these batteries finally "die", I'll use my new Eneloops.


----------



## Verndog

rwharold said:


> Thanks for your reply. Fortunately as you said, I'm using these very old Radio Shack MiMH 2000 mA batteries in a fire/police radio scanner. I can still charge them using the radio's 9V 300 mA power supply/charger. I listen to the scanner all day and the batteries still last about 12 to 16 hours! Remarkable for a "bad" battery! My only regret is that I can't use my brand new Maha C9000 charger, but I now understand what's going on. When these batteries finally "die", I'll use my new Eneloops.



I have no idea which cells you have there, but for a while Radio Shack sold some GP cells that were very good. I'd imagine it's totally hit and miss.


----------



## B-52

I'm new to Forum and I ran across this thread & wanted to ask on the R.S. Batteries). 

I have a MaHa C9000 wizard i'm Currently using in it PowerEX 2700mAh , And Corun 2300mAh batteries that came with my Uniden BCD 396xt scanner). I just got a Set of Eneloop XX's that i want to Run in 396 with the PowerEX's 

But for my remotes or other small things i thought maybe using the Radio Shack enercell 2500mAh might work but if the ones that were mentioned on here are not too Good or Don't work in the C9000 it makes me Wonder about the 2500's if there up to being charged in this charger.. 

Any thought on this Question would be Great... Thanks B


I wanted to Add please Tell me Were Go to Change "Unelightened" at since i'm all new this i'm still learning the Ropes on here but i would like to take that off or at Least Change it Thanks again..


----------



## Rexlion

You should have no problem charging the Radio Shack cells in the Maha. That charger will not charge cells that have gone bad and aren't taking a charge properly, but if the RS cells are in decent shape the Maha will do fine with them.

No way to change the 'unenlightened' moniker except by participation. When you get over a certain number of posts, it will change automatically.


----------



## merryman1888

I just got 4 AA & 4 AAA Imedions and was wondering if the C9000 can perform a full discharge then immediately a full charge? 

'Cause I don't like how the Break-in feature charges first, which can cause over charging damage. Even though it is only 140ma or so, it far more damaging than the trickle charge of 10ma.


----------



## rwharold

merryman1888 said:


> I just got 4 AA & 4 AAA Imedions and was wondering if the C9000 can perform a full discharge then immediately a full charge?
> 
> 'Cause I don't like how the Break-in feature charges first, which can cause over charging damage. Even though it is only 140ma or so, it far more damaging than the trickle charge of 10ma.



Run a "discharge" cycle first and then a "Break-in" cycle on new batteries.

The Maha Energy Corp. states: 

"Break-In mode, otherwise known as IEC capacity measurement and "Battery Forming," charges and discharges the batteries at a fraction of their full capacities. It charges them at 0.1C for 16 hr, rests for an hour, discharges them at 0.2C, and then recharges them once more at 0.1C for 16 hr, where C is the battery capacity. It is best used for new batteries or those stored for longer than 3 months, and chemically reactivates the battery after the deactivation that occurs with long-term storage."

You can also do a full charge after that if you want, but they should already be fully charged after the "Break-in" cycle.


----------



## rwharold

If your Imedions are LSD (low self discharge) type batteries, the you don't even need a "Break-in" cycle according to Maha Energy. Just discharge at 0.25 C and then charge at 0.5 C. But a lot of people like to do a "Break-in" cycle, so you can follow my earlier directions. Hope that helps.


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## rwharold

For those of you that have the Maha C9000 charger, there is a very nice travel/storage case available both from Amazon and ebay. It's called the: "Maha PowerEx Deluxe Padded Travel Case MHS-CC150". The link to the amazon page is: http://www.amazon.com/gp/product/B00BF2X74S/?tag=cpf0b6-20. The link to the eBay page is: http://www.ebay.com/itm/Maha-PowerE...y_Chargers&hash=item4aa5ac5eb0#ht_1055wt_1044. It's only $9.85 on eBay with FREE SHIPPING. I have one and it's a great storage/travel case made out of water resistant nylon with a Velcro attachment storage pouch on the outside which will hold 4 battery storage cases holding 4 batteries each for a total of 16 batteries in the pouch. Plus there is plenty of extra room in the main case for even more batteries. I would highly recommend this case to anyone looking for the ultimate protection for your Maha C9000 charger and batteries. Enjoy!


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## merryman1888

Thanks, for your fast reply. Yes, the Imedions are 2400mah (2250mah minimum) LSD, brand new from Thomas Dist. purchased through Amazon. 
I know I can do a discharge first, but I don't like to have the batteries sitting for awhile in the charger completely discharged, as I've heard it is harmful to discharge a battery and not immediately recharge it. 

I just don't understand why Maha didn't atleast give the option of a discharge prior to charge, on any of the forming features (Break-in, Refresh/Analyze, or Cycle).


----------



## rwharold

merryman1888 said:


> Thanks, for your fast reply. Yes, the Imedions are 2400mah (2250mah minimum) LSD, brand new from Thomas Dist. purchased through Amazon.
> I know I can do a discharge first, but I don't like to have the batteries sitting for awhile in the charger completely discharged, as I've heard it is harmful to discharge a battery and not immediately recharge it.
> 
> I just don't understand why Maha didn't atleast give the option of a discharge prior to charge, on any of the forming features (Break-in, Refresh/Analyze, or Cycle).



You are right. I just re-checked my instruction sheet. None of the Maha operations do an automatic discharge first. That is just the nature of their programming. You will manually have to do a discharge at 0.25C FIRST and then immediately do a charge at 0.5C SECOND. You are right about leaving a battery in a discharged state for a prolonged period of time. It will degrade the battery. I was wrong earlier about the "Break-in" cycle. Maha DOES recommend this operation for NEW batteries. Hope this helps!


----------



## Mr Happy

merryman1888 said:


> I just got 4 AA & 4 AAA Imedions and was wondering if the C9000 can perform a full discharge then immediately a full charge?
> 
> 'Cause I don't like how the Break-in feature charges first, which can cause over charging damage. Even though it is only 140ma or so, it far more damaging than the trickle charge of 10ma.



Well the break-in cycle is _supposed_ to overcharge the batteries. The idea of a break-in is to "stir up" the chemicals inside the battery, and if you don't overcharge and activate the recycle reactions inside the cell this will not happen to full effect.

An NiMH battery is supposed to offer hundreds of charge cycles before it wears out. If you run a break-in cycle four times a year the battery could still last longer than your lifetime before the cumulative effect is noticeable.

In other words, don't worry about it.



merryman1888 said:


> I've heard it is harmful to discharge a battery and not immediately recharge it.



I have seen no evidence to support this. A rechargeable battery will suffer damage if the electrode potentials cause adverse chemical reactions to occur. With NiMH batteries this certainly happens if you subject them to reverse polarization (that is, if you drive the voltage negative). However, discharging an NiMH cell down to zero volts, or storing it discharged at an open circuit voltage of about 1.2 V, has no evidence of harmful effects. In fact the opposite is probably the case. Storing a battery charged is like storing a spring compressed. It will weaken the spring.

If you want your NiMH batteries to last a long time in storage, then keeping them in a mostly discharged state is a good thing. They will not suffer at all.


----------



## merryman1888

Thanks for the info.


Mr Happy said:


> In fact the opposite is probably the case. Storing a battery charged is like storing a spring compressed. It will weaken the spring.


 Good analogy, I would naturally think likewise, but I did read somewhere that Silver Fox mentioned something about NiMH batteries not liking to be fully discharged. I guess if there is just enough voltage in the cell it'll keep it from damage, like lithium-ion.


----------



## merryman1888

This probably belongs in another thread, but I thought I'd ask it seen your here and are very knowledgeable. 
I have been curious, before I even purchased the C9000 charger. 
How does NLee the Engineer (or any of the others I've seen) get remaining Mah readings from cells without doing a charge/discharge cycle in the BC-series chargers? 


Like when they test how much a battery has discharged during shelf storage?

*"*Right out of the box, the average remaining charge is 692mAh,or 81% of the advertised capacity of '850mAh'*"* http://www.amazon.com/dp/B000NWIIE0/?tag=cpf0b6-20


----------



## Mr Happy

I think you have to put the cells on a discharge cycle and watch the mAh readings on the display before they start charging again.


----------



## merryman1888

Thanks. I'll try that on the C9000. Update: I guess just drain them with a discharge and the finish mah reading will be how many mah were discharged and I can then subtract this from the initial finished charged reading before they went in storage? 
That's probably what NLee does to get his determination of remaining mahs of cells in storage?


----------



## B-52

Rexlion said:


> You should have no problem charging the Radio Shack cells in the Maha. That charger will not charge cells that have gone bad and aren't taking a charge properly, but if the RS cells are in decent shape the Maha will do fine with them.
> 
> No way to change the 'unenlightened' moniker except by participation. When you get over a certain number of posts, it will change automatically.





Ok thank you Rexlion And for the Radio Shacks i got a Set i discharged them @ 100mA and then charged them @ 1000mA and Just before they got to 1.47 Volts around 1.45 Volts they got really Warm so Warm i pulled them out of the Charger i won't buy them again i'll stick with my 2000mAh eneloops my XX and my PowerEX 2700's they get slightly warm but not near like them Darn enercells did..


----------



## rwharold

Mr Happy said:


> Well the break-in cycle is _supposed_ to overcharge the batteries. The idea of a break-in is to "stir up" the chemicals inside the battery, and if you don't overcharge and activate the recycle reactions inside the cell this will not happen to full effect.
> 
> An NiMH battery is supposed to offer hundreds of charge cycles before it wears out. If you run a break-in cycle four times a year the battery could still last longer than your lifetime before the cumulative effect is noticeable.
> 
> In other words, don't worry about it.
> 
> 
> 
> I have seen no evidence to support this. A rechargeable battery will suffer damage if the electrode potentials cause adverse chemical reactions to occur. With NiMH batteries this certainly happens if you subject them to reverse polarization (that is, if you drive the voltage negative). However, discharging an NiMH cell down to zero volts, or storing it discharged at an open circuit voltage of about 1.2 V, has no evidence of harmful effects. In fact the opposite is probably the case. Storing a battery charged is like storing a spring compressed. It will weaken the spring.
> 
> If you want your NiMH batteries to last a long time in storage, then keeping them in a mostly discharged state is a good thing. They will not suffer at all.



I contacted NLee, the Engineer about your comment of storing NiMH batteries in "a mostly discharged state". Here is his response:

Rick,
I disagree with what Mr. Happy said:
("If you want your NiMH batteries to last a long time in storage, then keeping them in a mostly discharged state is a good thing. They will not suffer at all.")

1. For ordinary NiMH cells (with high self-discharge rate), storing them in mostly discharged state is just asking for trouble. The batteries will self-discharge to zero volt, and then the next time you try to use them, they will start with lower capacity and require several cycles to slowly gain back the capacity. That's what the BREAK-IN operation of Maha C9000 is supposed to be used for.

2. For low-self-discharge cells like Sanyo eneloop, they are designed to hold their charges for years in charged state. Sanyo claims 3rd-gen eneloop can retain 70% of charge after 5 years. I believe that because I have tested some first-gen eneloop cells after 3.5 years in storage. They still retain ~70% of charge right out of the package (and we know that eneloop cells are only charged to 75-80% when they left factory). Furthermore, they returned to >90% of rated capacity after just one recharge. That's why I always tell people BREAK-IN is unnecessary for LSD cells even after prolonged storage. But of course, I never intentionally drain LSD cells down to zero voltage and store them for months before test, just to see whether there is any harmful effect.

3. For NiCd cells, I know for a fact that storing them in completely discharged state for several months is a BAD idea. Doing so will lead to reduced capacity and sometimes even dead short (something to do with crystal grow that punctures the separator).

4. For electrolytic capacitor (which is also a electro-chemical device similar to rechargeable batteries), I know for a fact that storing them in discharged state for months will lead to reduced capacity and high leakage current on the next recharge. It will then take several cycles to get the capacity back, just like in the case for ordinary NiMH cells.

So my firm conviction is that you should store eneloop (or any other LSD NiMH cells) in charged state. Whether they are fully charged to 100% or just partially charged to 75%, that is not so important in this case.

For ordinary NiMH, however, you cannot keep then in charged state for long due to self-discharge. But at least you should start from a fully charged state, instead of intentionally discharging them before storage.


----------



## Russel

Huh, I keep my extra Eneloops in the frig. at about 10 percent charge. I recently pulled a couple out that have been stored for three years and did a break in to re-distribute the electrolyte within the cells. I was surprised that their performance was the same as new cell.

1948 mAh
1973 mAh


----------



## rwharold

Russel said:


> Huh, I keep my extra Eneloops in the frig. at about 10 percent charge. I recently pulled a couple out that have been stored for three years and did a break in to re-distribute the electrolyte within the cells. I was surprised that their performance was the same as new cell.
> 
> 1948 mAh
> 1973 mAh



I checked Sanyo's Eneloop website and this is what they said about storing your Eneloops:

"If stored with charge, it is possible that when you return to use the battery there may still be some charge left in the battery, therefore it will enable you to use it right then and there. Also, by keeping some charge in the battery, it will require you to "cycle" the battery fewer times until it reaches its peak charge. If you store them with no charge, you will have to "cycle" the battery multiple times until it reaches its peak charge."


----------



## Mr Happy

rwharold said:


> I contacted NLee, the Engineer about your comment of storing NiMH batteries in "a mostly discharged state". Here is his response:
> 
> 
> 
> 
> Rick,
> I disagree with what Mr. Happy said:
> ("If you want your NiMH batteries to last a long time in storage, then keeping them in a mostly discharged state is a good thing. They will not suffer at all.")
> 
> 1. For ordinary NiMH cells (with high self-discharge rate), storing them in mostly discharged state is just asking for trouble. The batteries will self-discharge to zero volt, and then the next time you try to use them, they will start with lower capacity and require several cycles to slowly gain back the capacity. That's what the BREAK-IN operation of Maha C9000 is supposed to be used for.
Click to expand...


This temporary loss in capacity will occur when you store NiMH batteries unused for a long time, whether charged or discharged. The only way to keep NiMH batteries performing well is to keep using them (or at least to cycle them every few months).

One should distinguish between temporary loss in capacity and permanent deterioration. Permanent deterioration is accelerated by the self-discharge process, so putting (ordinary NiMH) batteries in to storage fully charged is going to be more harmful than putting them into storage partially charged.



> 2. For low-self-discharge cells like Sanyo eneloop, they are designed to hold their charges for years in charged state. Sanyo claims 3rd-gen eneloop can retain 70% of charge after 5 years. I believe that because I have tested some first-gen eneloop cells after 3.5 years in storage. They still retain ~70% of charge right out of the package (and we know that eneloop cells are only charged to 75-80% when they left factory). Furthermore, they returned to >90% of rated capacity after just one recharge. That's why I always tell people BREAK-IN is unnecessary for LSD cells even after prolonged storage. But of course, I never intentionally drain LSD cells down to zero voltage and store them for months before test, just to see whether there is any harmful effect.



Low self-discharge cells like eneloops are special, and can be treated differently from traditional NiMH cells. Because they hold their charge well in storage they do not suffer from the deterioration caused by self-discharge that traditional NiMH cells suffer from. However, eneloops suffer a temporary loss in performance after long storage just like other cells. This loss in performance is experienced as a higher internal resistance, greater voltage sag under load and lower measured capacity. Even eneloops have to be cycled or run through a break-in cycle if you take them out of long term storage and want them to operate at peak performance.



> 3. For NiCd cells, I know for a fact that storing them in completely discharged state for several months is a BAD idea. Doing so will lead to reduced capacity and sometimes even dead short (something to do with crystal grow that punctures the separator).



If you refer to the NASA technical manual on use of NiCd batteries in the space program, it recommends preparing NiCd cells for storage by doing a controlled discharge to zero volts and then shorting out the terminals to keep them this way. It has long been recognized that storing NiCd cells at zero volts is safe and effective.

The situation is unclear whether NiMH cells can be treated the same way. Nobody has provably damaged an NiMH cell by completely discharging it to zero volts, but nobody has proven it is better than any other storage technique either.



> 4. For electrolytic capacitor (which is also a electro-chemical device similar to rechargeable batteries), I know for a fact that storing them in discharged state for months will lead to reduced capacity and high leakage current on the next recharge. It will then take several cycles to get the capacity back, just like in the case for ordinary NiMH cells.


Electrolytic capacitors are not NiMH cells. You cannot infer from one to the other.



> So my firm conviction is that you should store eneloop (or any other LSD NiMH cells) in charged state. Whether they are fully charged to 100% or just partially charged to 75%, that is not so important in this case.



Yes, it is fine to store eneloops charged. But recognize that after two years of storage, even though they have maintained their charge, they will still need a break-in cycle to recover maximum performance.



> For ordinary NiMH, however, you cannot keep then in charged state for long due to self-discharge. But at least you should start from a fully charged state, instead of intentionally discharging them before storage.



If you put them away charged, the self-discharge will damage them. You should put them away at about 20% charge, and make sure to run them through a charge/discharge cycle every six months or so. Ordinary NiMH batteries should not be ignored, they should be actively maintained if you want the best use out of them.


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## SilverFox

Hello Rick,

This is a very interesting discussion...

What is missing is definitions of terms.

NLee states that NiMh batteries stored will self discharge to 0 volts. This may in fact be true, but what is the time needed for this to happen? I picked up a NiMh battery pack that I pulled from a cell phone. Do you remember when cell phones used NiMh battery packs? I don't know the last time I charged it, but let's say that it has been at least 4 years. I do know that it was stored discharged. There has been some self discharge, but the voltage didn't quickly drop to 0 volts. It dropped, over around 4 years, to 0.8 volts per cell. 

Another example has to do with NiCd cells. I had the opportunity to get some "new in package" D size NiCd cells. These are Everready 1200 mAh D cells. These cells had been stored for at least 10 years. Once again the voltage was not 0. Most of the cells measured 0.6 volts, but there was one that had dropped to 0.4 volts. When charged up and put through 2 charge/discharge cycles, they all came back to 1050 mAh, which is probably very close to their initial capacity.

The other aspect of this has to do with the quality of the initial cell. If you start with crap cells..., you can't expect them to handle abuse very well.

Years of experience in RC racing and hobby use has revealed that the best way to store NiMh and NiCd battery packs for the short term is to discharge the pack to 1.0 volts per cell and store it. Longer term storage involves subjecting the pack to a charge/discharge cycle every 30 days for the best results, but that can be stretched out to every 90 days if you are less picky about the packs performance. 

There has been quite a lot of debate about storing NiCd (and later NiMh) battery packs shorted. This debate raged on and on and there was data showing benefits on both sides so there never was a consensus showing benefits one way or the other. NASA did some research on this and concluded that storing individual NiCd cells shorted was OK, but that did not apply to battery packs made up of several cells. I will say that in all my years of RC racing I never stored "active" packs shorted. I tried it a few times and didn't see enough benefit to warrant the added effort. Also, the more advanced chargers didn't like initiating a charge on a pack that was stored shorted.

If we define normal storage as having a NiMh battery stored for one month or so, store them in a discharged state.

If you charge a NiMh battery and don't get around to using it until a week has passed, just use it. If you think you are going to need every mAh you can get and don't have any extras you can top it off before use. If the battery self discharges in that week it is crap and needs to be recycled and replaced.

If the definition of long term storage is a year or many years, you need to question if your purchase decision was sound. Still there are times when we get carried away and purchase more than we need for immediate use. To keep batteries vibrant in long term storage takes some work. You start with a Break In cycle (after an initial discharge prior to starting the Break In, but this is not critical). Mark the battery and record the results. Discharge at 500 mA using the C-9000 and store. Every 30 or 60 or 90 days (your choice) do a charge/discharge cycle and store again. Every year do another Break-In and once again record the results. If the Break-In results fall below 80% of the initial Break-In, recycle the cell.

Enough theory, let's move to actual experience. I follow the store discharged and cycle every 30 days plan. I have 8 B90 SureFire battery packs that still work almost as good as they did when they were new. I have 4 of the B90 NiMh battery packs that I put together several years ago with GP batteries and they are still giving me "twice the run time and brighter" performance. I have 16 Titanium 2400 cells (made by Panasonic) that I have used over and over again for testing and they are still not ready for the recycle bin.

To be fair there is also the other side of the story. I just recycled 8 Energizer 2300 mAh cells that I tried to take good care of but they developed such a high rate of self discharge that I got rid of them. I also have 8 Sanyo 2500 mAh batteries that will self discharge within a week but on a daily basis still give good performance. I came up with a use for those cells that involves a 1 day use so they haven't been recycled... yet. Many have seen this high self discharge problem with the higher capacity NiMh batteries so it comes down to a judgement call of when to call them crap.

Storing NiMh batteries discharged slows down the chemical reaction going on inside the cell. It basically puts the cell into hibernation. The self discharge process seems to degrade the battery faster than hibernation does, so it is beneficial to store in a discharged state. 

The bottom line is that it is better to become attached to flashlights... and not batteries. Purchase enough batteries for your needs but don't get carried away. Batteries like to be used and not stored. You will enjoy better performance using your batteries than storing them.

Tom


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## Russel

rwharold said:


> I checked Sanyo's Eneloop website and this is what they said about storing your Eneloops:
> 
> "If stored with charge, it is possible that when you return to use the battery there may still be some charge left in the battery, therefore it will enable you to use it right then and there. Also, by keeping some charge in the battery, it will require you to "cycle" the battery fewer times until it reaches its peak charge. If you store them with no charge, you will have to "cycle" the battery multiple times until it reaches its peak charge."



Yes.

That is why I ran a break-in cycle on the batteries that I had stored, after letting them reach room temperature. After storage at 10 percent charge for three years there is no apparent degradation of capacity. (I should clarify: I originally stored them at about 10 percent charge. After I removed them from the fridge three years later, and let them reach room temperature, I simply placed them in a MH-C9000 charger and let them charge at the default rate of 1 Amp. I made no attempt to measure the state of charge at that point.)

PS I usually cycle stored batteries every three to six months, but these particular cells had fallen behind some other containers in the fridge and I didn't notice them until recently. I was surprised by the date on the ziplock bag that I stored them in.


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## rwharold

Thanks for all the very insightful information on the subject of Eneloop storage. Eneloops are designed to be stored in a charged state according to their technical support representative. I'll stick with Eneloop's official statements on proper usage.


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## snakebite

just noticed an anomaly.
4 new duraloop duralock after several cycles stabilised in the high 1800's.
default 1000ma charge 500ma discharge.
but at the 1000ma discharge rate i get low 1900's.
going to grab a good 4aa holder and repeat the test with a triton...


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## merryman1888

I know this is a change of subject and some of these topics on this thread probably belong in others and vise versa, but this topic pertains to the C9000. I thought I would bring up the charge termination on the C9000 vs. the BC-1000-series). NLee states: _*[Q16] Can I use the Maha to recharge Sanyo eneloop batteries?
[A] Yes, but the voltage cut off threshold (around 1.48V) is too low for eneloop. So the batteries will not be fully charged to 100% when the status says 'DONE'. You should leave them in the charger for 2 hours for the top-off current (100mA) to finish the job. *_http://www.amazon.com/review/RZCMBY...ead=TxRAPJHF5ZAN99&store=photo#wasThisHelpful*
*
Is it true, I'll have the same capacity with Eneloops in the C9000 after letting them sit for the top-off as I would for the BC-1000 after it's 1.53V cut-off? 'Cause I've seen others state higher capacities from the BC-series chargers. 

With which asks the question is a little more capacity worth shorter and/or less long-term battery life?

Also, I've seen others state not just higher capacity, but less fluctuation in finished capacities of cells in the BC-series chargers. I'm curious if any of ye have seen this?

If it helps my C9000 was purchased 3 mons. ago off Amazon. Thanks, Will


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## SilverFox

Hello Merryman1888,

Different test methods tend to yield different results.

The BC-1000 in test mode charges the cell, then immediately while the cell is still warm from the charge it will run the discharge. 

The C-9000 in the Break In mode that determines cell capacity allows for a rest period after charging before it starts the discharge. This allows the surface charge to dissapate and gives you a little less optimistic capacity values.

When using NiMh cells for RC racing the general rule was to use the packs "hot off the charger." The extra surface charge may make the difference between winning and losing in a close race. With flashlight use the extra surface charge doesn't play much of a factor unless your light goes through a set of batteries in 5 - 10 minutes.

If you watch the voltage on the C-9000 after Done shows up, you will see it climb to over 1.5 volts during the top off charge. In addition the top off charge is a little easier on the cell so you can expect extended life from it. 

I ran some comparison tests with the BC-900 and the C-9000. The cells were charged, left to rest for 30 minutes, then discharged on a CBA. The cells charged on the C-9000 ended up with a little over 5% more capacity than those charged with the BC-900. I don't believe the charging algorithm has changed in the BC-1000 and I am not aware of any formal test comparisons done between those two chargers.

Tom


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## merryman1888

Thanks, I value your and Mr. Happy's input. What about the greater varying in finished mah readings on the C9000 vs. the BC-series's closer more flat/consistent finished mah readings I've seen others comment on. Is the C9000 been more accurate here too? 

Actually, NLee has the BC-900 which is the main one he uses, although he owns all four of the LaCrosse smart chargers and the C9000. http://www.amazon.com/dp/B004J6DLD4/?tag=cpf0b6-20
 Thanks, Will


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## SilverFox

Hello Will,

Variations seem to be an integral part of life...  

I will have to see how much variation there actually is. I believe the Break In mode is reasonably accurate.

When I am looking for an accurate assessment of capacity I use my CBA to measure the discharge capacity. It is more accurate than any retail charger.

Tom


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## merryman1888

CBA is that an acronym for Cell Battery Analyzer?


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## Mr Happy

merryman1888 said:


> CBA is that an acronym for Cell Battery Analyzer?



It's a specialist (and not inexpensive) product for battery testing:

http://www.westmountainradio.com/cba.php


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## EneloopFan

Hello everyone! I'm trying to buy the PowerEx MH-C9000. I'd like to know the model number of the very latest version. It seems that in some websites, the refurbished or RMA merchandise is being sold as brand new PowerEx MH-C9000. Can someone please provide me the model number of the very latest version and does the LCD screen wear out quickly in the latest model too?


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## samgab

EneloopFan said:


> Hello everyone! I'm trying to buy the PowerEx MH-C9000. I'd like to know the model number of the very latest version. It seems that in some websites, the refurbished or RMA merchandise is being sold as brand new PowerEx MH-C9000. Can someone please provide me the model number of the very latest version and does the LCD screen wear out quickly in the latest model too?



It's not a "model number". The code is a date of manufacture notation for manufacturer's use:



First Pair:Second Pair:0F20060AJanuary0G20070BFebruary0H20080CMarch0I20090DApril0J20100EMay0K20110FJune0L20120GJuly0M20130HAugust...0ISeptember0JOctober0KNovember0LDecember



So the latest version, if they've made any batches this month or last month would be 0M0KA or 0M0LA.
But anything that starts with 0M should be recent enough - manufactured this year.
I haven't had any issues with the screen on my one - an *0K*XXX DOM version (2011).
If you go to a _*reputable supplier*_ I doubt they'd try to pass off a refurbished or returned one as brand new.


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## Artivideo

Does the 808M also have a restingperiode between the charge and the decharge and the decharge and the charge ?





SilverFox said:


> Hello Merryman1888,
> 
> Different test methods tend to yield different results.
> 
> The BC-1000 in test mode charges the cell, then immediately while the cell is still warm from the charge it will run the discharge.
> 
> The C-9000 in the Break In mode that determines cell capacity allows for a rest period after charging before it starts the discharge. This allows the surface charge to dissapate and gives you a little less optimistic capacity values.
> 
> When using NiMh cells for RC racing the general rule was to use the packs "hot off the charger." The extra surface charge may make the difference between winning and losing in a close race. With flashlight use the extra surface charge doesn't play much of a factor unless your light goes through a set of batteries in 5 - 10 minutes.
> 
> If you watch the voltage on the C-9000 after Done shows up, you will see it climb to over 1.5 volts during the top off charge. In addition the top off charge is a little easier on the cell so you can expect extended life from it.
> 
> I ran some comparison tests with the BC-900 and the C-9000. The cells were charged, left to rest for 30 minutes, then discharged on a CBA. The cells charged on the C-9000 ended up with a little over 5% more capacity than those charged with the BC-900. I don't believe the charging algorithm has changed in the BC-1000 and I am not aware of any formal test comparisons done between those two chargers.
> 
> Tom


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## SilverFox

Hello Artivideo,

Welcome to CPF.

I don't believe it does. It also doesn't give you the capacity of the discharge. It just cycles the cells.

Tom


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