# Maha MH-C9000 SUPPORT / FAQ Thread



## willchueh

I would like to start this thread to answer user questions about the MH-C9000. The 2nd post contains a FAQ which shall be amended from the time to time. 

For features and general pre-sales questions/discussion, please use this thread:
https://www.candlepowerforums.com/threads/140144

William


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## willchueh

*Re: Maha MH-C9000 SUPPORT Thread*

*MH-C9000 Frequently Asked Questions
*
Updated Jan. 5, 2007

*Using the BREAK-IN mode, I am seeing a charging capacity much higher than the capacity I programmed. Why is the battery overcharged? 
*
When using the BREAK-IN mode, the charger puts in 1.6 times the capacity of the battery (entered at the start of the charge). This does not cause any harm to the battery as the charging rate is very low (only 10% of the battery capacity). The increased total charging capacity compensates for energy lost as heat. This is the charging scheme recommended by International Electrotechnical Commission (IEC). 



*I am charging some older batteries and see that the charging capacity is much higher than the capacity I programmed. Why doesn't the charger terminate correctly? 
*
The charger terminates by voltage and by temperature simultaneously. For certain older (and low quality) batteries, they do not produce the proper negative delta V signal (a small voltage drop at the conclusion of the charge) needed for the charger to stop. At the same time, the battery temperature failed to reach the termination limit as the charging rate was probably too low.

To address this issue, you should attempt to perform a BREAK-IN mode on the batteries first. You should also use a higher charging rate. 



*When using higher charging current, the charging capacity seems to reduce. Is this normal? 
*
When charging at higher current, the charge completeness reduces thereby lowering the charging capacity. This is to prevent battery overheating. This typically occurs at a rate greater than 1500mA. Generally speaking, 1000mA achieves nearly full charge completeness for AA batteries. 

Even after the charge ends (DONE appears on screen), the charger will apply a topoff charge and continuous maintenance charge. Despite that the capacity on the screen no longer increases, the batteries are being topped off. 

If you would like to achieve better charge completeness at higher currents, a small fan can be added to cool the batteries externally. 



*Why is it not recommended to charge battery below 0.33C? 
*
When charging below 0.33C (except in BREAK-IN) mode, the batteries may not produce a sufficient end-of-charge signal for the charger to terminate correctly. Although the temperature sensors will safeguard battery overheating, lower charging rate might not cause enough heating in the batteries to trip the sensors. 

If low charging rate is desired, you should use the BREAK-IN mode. Charging in that mode is terminated by only time (1.6 times battery capacity) and temperature. 



*After the charge begins, why do I see an abnormally high voltage (~ 1.6V to 2.0V) on the screen? 
*
In the first few seconds, the MH-C9000 performs a proprietary "high impedance" check to filter out batteries unsafe to charge including non-rechargeable batteries. During this time, a high current is applied and voltage measured to determine the impedance of the battery. 

The voltage will return to normal by the second time voltage data is displayed on the screen. 



*Why doesn't the charging and discharging current reach the set values exactly? I thought the charger is supposed to be precise. 
*
The charging and discharging current are pulsed, thereby causing the displayed current to go up and down. The capacity calculation is based on the actual current rather than the set current so capacity calculation remains accurate. 



*I am using the CHARGE mode. Why is the capacity different than my battery capacity? 
*
The capacity displayed in any charging process is called the "charging capacity." This is the amount of energy put into the batteries. This number does not equal to the battery's capacity as it is dependent on the amount of charge already in the battery as well as the battery's internal resistance. 

For example, a half used 2000mAh battery may only show a charging capacity of 1000mAh since the battery is half full. 

It is normal for the charging capacity to exceed battery capacity by as much as 30% depending on battery brand and charging rate. 

To determine the battery's useful capacity, you must look at the "discharge capacity." Such information is available in the REFRESH & ANALYZE, BREAK-IN, DISCHARGE, and CYCLE modes. Note that the battery is not recharged in the DISCHARGE mode. 



*How do I tell if the capacity displayed on the screen is charging or discharging capacity?
*
If charging or discharging is in-progress, a blackbox contain either CHARGE or DISCHG will be displayed on the screen. The capacity shown during charging is always the charging capacity. Similarly, the capacity shown during discharging is the discharging capacity. 

In the CHARGE mode, the final capacity displayed (after DONE appears) is the charging capacity.

In the REFRESH & ANALYZE and BREAK-IN mode, the final capacity displayed is the discharging capacity. The battery have also been recharged after the discharge. 

In the DISCHARGE mode, the final capacity displayed is also the discharging capacity. However, the battery is not recharged. 

In the CYLCE mode, the capacities saved in memory always refer to the discharging capacity.



*When I discharge certain batteries, the current seem to taper off near the end of the discharge and seems to take very long to finish. Why and does this affect the capacity of the battery?*

This is normal for batteries that exhibt high internal resistsance. MH-C9000 measures the voltage of the batteries while briefly pausing the discharge (every few seconds). For high resistance battery, this voltage might differ from the actual voltage of the battery. For the MH-C9000, it is not designed to maintain set current when battery is below 0.9V. 

This does not affect the calculated capacity as the realtime current is used in the capacity integration. 



*Using the CYCLE mode, why do I see a "0 mAh" capacity on the screen? What happened to the saved battery capacity? 
*
A CYCLE is consisted of:
Charge > 1 Hour Rest > Discharge > 1 Hour Rest (repeats for programmed number of times) 
The discharge capacity is saved into the memory at completion of discharge but cannot be reviewed until that cycle is completed (after the 1 hour rest). During the rest, a zero capacity is displayed.

During this period, all previously completed cycle data can be viewed, but not the most recent cycle. It will become available after that particular cycle is completed. 

Cycle data can be accessed anytime after completion of the first cycle by using the "UP" and "DOWN" keys. 



*There is an arrow that moves below the slot number. What does it mean? *

The LCD screen displays information a slot at a time. The information (capacity, current, time, voltage) is displayed twice before moving on to the next slot. The arrow points to the slot reporting. 



*Is it normal for the batteries to get warm during charging?
*
Yes, batteries do get warm during the charge due to both internal heat and heat produced by the charger. Lower charging rate can yield lower battery temperature, but it is not recommended to go below 0.33C or 0.33 times the battery capacity. 

Adding an external fan can also cool the battery. 



*The manual makes recommendations for charging rates. How about discharging rate*

Most NiMH batteries can accept discharge rate up to 3 times its capacity. A higher discharge rate will yield lower capacity. 

For accurate capacity measurement, use the BREAK-IN mode which complies with IEC standards (0.2C discharge rate). 



*Is the MH-C9000 compatible with the new "low self-discharge" batteries (e.g. Sanyo Eneloop)? *

Yes. Follow the same charging rate recommendations for general NiMH batteries. 



*What is the maximum capacity supported by the MH-C9000?
*
The maximum capacity supported is 20,000mAh making it compatible with future technologies. 



*The charger cannot detect my battery. What can be done? 
*
Virtually all batteries can be detected by the charger. Therefore, if a battery cannot be detected, it is likely not making good contact with the charger. This can be caused by improper seating of the battery or battery not meeting the IEC dimension standard. Try rotating the battery or placing it in another slot.



*There is a faint noise emanating from the charger. Is this normal? 
*
The charger can produce some high frequency hum, which is generated by the high frequency pulse charging and switchers.


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## coppertrail

Thanks Bill!


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## dekelsey61

Thank you very much- William. Lots of imformation to help us out. Great work.
Dan


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## thekobk

I orderd a 4 pack of maha 2700's with my new charger and was wondering do I need to put the new battery's on discharge mode before I put them in break in mode?:huh2:


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## willchueh

thekobk said:


> I orderd a 4 pack of maha 2700's with my new charger and was wondering do I need to put the new battery's on discharge mode before I put them in break in mode?:huh2:




thekobk,

You can use the discharge mode, if desired (I recommend 500mA), but not necessary. For most cases, simply use the BREAK-IN mode which does the following:

Charge at 0.1C (270mA) for 16 hours
Rest 1 hour
Discharge at 0.2C (540mA)
Rest 1 hour
Charge at 0.1C (270mA) for 16 hours

Once should suffice. Be advised it takes quite a while (39 hours).

This is also useful for batteries that've been in storage. From my experience, it can do pretty wonderful things to dead batteries.

William


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## thekobk

Thank you William for your response. So far I like this charger alot. Might give my bc900 away as a christmas gift. The bc 900 was a good charger but this things is the cats meow.:rock:


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## dekelsey61

William, Thanks for all your help with this new charger. I am using the break-in mode on 4- 2700mah batteries that has had a faster discharge rate than all the rest of my batteries. With the break-in mode will it help batteries that have a faster discharge rate than other ones? This charger is GREAT!! Thank you.
Dan


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## Mike abcd

thekobk said:


> I orderd a 4 pack of maha 2700's with my new charger and was wondering do I need to put the new battery's on discharge mode before I put them in break in mode?:huh2:



IMHO, I'd definitely discharge them first or better yet, condition them with the refresh mode a couple of cycles or until the reported capacity stabilizes.

It takes 12 hours at .1C to fully charge a fully discharged NIMH cell per Duracell. That's also what I found when I did a quick test. Anything beyond that is overcharging and overcharging, even at .1C, is not good for NiMH cells. A 16 hour charge at .1C is roughly a 30% overcharge and can be a LOT more if the cell isn't fully discharged beforehand. I've found quite a few new cells with substantial initial charge out of the wrapper.

I know popular wisdom is that new cells should be "formed" with a 16 hour .1C charge but I can't find any cell manufacturer who advises it.

I also believe new cells require cycling and won't exhibit stable or full capacity on the first cycle. I've even seen poor cells that require 4-5 cycles such as the Lenmar junk. I just don't believe that you have to abuse them with overcharging based on my experience.

Running for my flameproof suite now...

From the FAQ.
"*Using the CYCLE mode, why do I see a “0 mAh” capacity on the screen? What happened to the saved battery capacity? 
*
A CYCLE is consisted of:
Charge > 1 Hour Rest > Discharge > 1 Hour Rest (repeats for programmed number of times) 
The discharge capacity is saved into the memory at completion of discharge but cannot be reviewed until the cycle is completed (after the 1 hour rest). During the rest, a zero capacity is displayed. However, as soon as the rest is completed, you can use the “UP” and “DOWN” key to access the capacities saved in memory."

Ouch, I hope this gets modified in a future firmware. Sounds like a bug, sloppy programming or a very foolish design decision. I guess I'll be doing a lot of seperate charge and discharge cycles on mine instead of using the "Cycle" mode.

Does anybody know if you can insert multiple cells at once and only have to set the parameters once like the BC-900? If not, I hope that also gets changed in a future firmware revision.

Mike


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## Mike abcd

Question:

Does the C-9000 only perform a 1 hour .1C top off charge after charging terminates based on dT/dt and not on -dV/dt or maximum temperature limit?

Is there a reason that it uses a .1 C 1 hour top off and not the .1C for 1/2 hour advised by Duracell, Sanyo and Energizer?

Mike


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## Curious_character

Hm, Maha recommends charging at no less than 0.33C, and says the new charger supports batteries up to 20,000 mAh. I conclude then that it's capable of a charge current of 6.67 amps. Impressive!

c_c


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## willchueh

Mike abcd said:


> Ouch, I hope this gets modified in a future firmware. Sounds like a bug, sloppy programming or a very foolish design decision. I guess I'll be doing a lot of seperate charge and discharge cycles on mine instead of using the "Cycle" mode.



Mike,

It seemed our FAQ response is very unclear and perhaps misleading. Sorry! Fortunately, I don't think the problem you are worried about exists. 

Basically, there is a one hour period during a SINGLE cycle which the capacity FOR THAT CYCLE cannot be viewed. All previously completed cycles can be accessed at anytime.

Here is an example:

You are at the 5th cycle, just after the the charger enters the post-discharge rest. Pressing the UP and DOWN key you can review 1st through 4th cycle, but you cannot see the capacity from the 5th cycle until the end of the rest period. 

William


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## Mike abcd

willchueh said:


> Mike,
> 
> It seemed our FAQ response is very unclear and perhaps misleading. Sorry! Fortunately, I don't think the problem you are worried about exists.
> 
> Basically, there is a one hour period during a SINGLE cycle which the capacity FOR THAT CYCLE cannot be viewed. All previously completed cycles can be accessed at anytime.
> 
> Here is an example:
> 
> You are at the 5th cycle, just after the the charger enters the post-discharge rest. Pressing the UP and DOWN key you can review 1st through 4th cycle, but you cannot see the capacity from the 5th cycle until the end of the rest period.
> 
> William



I still understand that as not being able to view the result of the LAST discharge cycle until 1 hour after the LAST discharge cycle completes.

That's just wrong. You have the capacity measured in the dischage test. Why wait an hour to provide it to the user? The rest period isn't going to change the result.

Mike


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## SilverFox

Hello Mike,

Got your flame proof suit on...  



Mike abcd said:


> IMHO, I'd definitely discharge them first or better yet, condition them with the refresh mode a couple of cycles or until the reported capacity stabilizes.



If you do a "forming" charge first, the capacity of the cell will stabilize pretty much on the first discharge cycle. With cells that have been "formed" you actually see very little change in capacity during cycling.



> It takes 12 hours at .1C to fully charge a fully discharged NIMH cell per Duracell. That's also what I found when I did a quick test. Anything beyond that is overcharging and overcharging, even at .1C, is not good for NiMH cells. A 16 hour charge at .1C is roughly a 30% overcharge and can be a LOT more if the cell isn't fully discharged beforehand. I've found quite a few new cells with substantial initial charge out of the wrapper.
> 
> I know popular wisdom is that new cells should be "formed" with a 16 hour .1C charge but I can't find any cell manufacturer who advises it.
> 
> I also believe new cells require cycling and won't exhibit stable or full capacity on the first cycle. I've even seen poor cells that require 4-5 cycles such as the Lenmar junk. I just don't believe that you have to abuse them with overcharging based on my experience.
> 
> Running for my flameproof suite now...
> 
> Mike



Duracell has excellent information. It has long been known that if we only charge to 90% of full capacity, keep the cells cool, and avoid prolonged trickle charging, the cells will last a lot longer. Unfortunately, they don't supply any data to back this up. Their cells are not advertised as being able to run for more cycles using their charging procedure, and if you follow it precisely, you will find that you loose around 10% in capacity.

Let's look at the 12 hour 0.1C charge. With cells that have been formed and cycled and in general are broken in, a 12 hour charge will get you within 95% of full capacity. This is charger dependent. Constant current chargers do better than pulsed chargers. 14 hours gives a little overcharge, but does a better job of redistributing the electrolyte within the cell. 16 hours is considered a "standard" charge according to the battery testing standards. The battery manufacturers use the "standard" charge to rate the capacity of their cells. While they don't come out and directly say so, I suspect Duracell uses the "standard" charge to rate their cells as well.

You have to ask yourself, “If the cell is fully charged at 12 hours, and can be damaged by overcharging beyond that, why does the industry standard call for a 16 hour 0.1C charge?”

Yes, the 16 hour charge does overcharge the cell. However, that little bit of overcharge seems to enable the cell to operate at its fullest potential right away. The next time you charge the cell, it will not develop hot spots, and if you use several cells in a battery pack, you find that they stay in balance better. The 16 hour charge also allows for better balancing of the cells within a battery pack.

The alternative is to do several cycles. 

In "normal" use, people won't observe the slight performance improvements that come from cycling, and no one wants to baby sit a "forming" charge. People would be outraged if the manufacturers insisted on them doing a forming charge prior to use. The people may even insist that the manufacturer do the forming charge at the factory before sending the cells out. Sanyo, and others, originally did this along with adding a few cycles to the cell before sending it out. Cost cutting has eliminated this step as being unnecessary for "normal" use.

There are some of us that are "performance" users. We measure run time down to the minute (and sometimes down to the second). We measure light intensity changes with a lux meter and are very interested in getting the best performance from our cells. We are also patient enough to do a 16 hour charge, and have the equipment to dial in the 0.1C charge rate. We also want "fully" charged cells in order to get every minute of run time we can from the charge.

The abuse comes from extended trickle charging. A cell is going to be as full as it can get in 16 hours at 0.1C. If you let it continue to charge for a week, the electrolyte will start to dry up. If you continue the charge for a year, you will see a performance drop. 

Duracell offers some interesting graphs. While they are not based on “standard” test parameters, they are very informative. 

Let’s take a look at they cycle test data for an example. The standard cycle test calls for a 0.1C charge for 16 hours, followed by a 0.2C discharge to 0.9 – 1.0 volts. This is continued until the capacity of the cell is at less than 80% of its original capacity.

Duracell offers a cycle test graph showing the effects of cycle life with charging and discharging temperature. They charge at 0.25C for 3.2 hours. This gives you roughly a 75% full cell. They discharge at 0.25C for 2.4 hours. The interesting part is that they measure capacity every 50 cycles by charging at 0.33C for 5 hours followed by a 1.0C discharge to 1.0 volts. The 0.33C charge for 5 hours works out to a 165% charge. I find it interesting that this is actually a higher overcharge than charging 16 hours at a 0.1C rate. It is also interesting that charging at a higher charge rate is more efficient, so it is a significant overcharge. To get the same results as charging for 16 hours at 0.1C when charging at 0.33C, you only need to charge for around 4 hours.

Fortunately, batteries handle a reasonable amount of abuse and still work well. Duracell offers some excellent advice, and looking at it from a consumers point of view, I agree with it. However, when I want peak performance from my cells, I will consider giving up some “longevity” for improved performance. 

Tom


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## dekelsey61

Hi Tom, Can you answer this question I have about a forming charge helping with faster than normal discharge rate. Will it work and help?Thank you and have a Happy Holiday!
Dan


dekelsey61 said:


> William, Thanks for all your help with this new charger. I am using the break-in mode on 4- 2700mah batteries that has had a faster discharge rate than all the rest of my batteries. With the break-in mode will it help batteries that have a faster discharge rate than other ones? This charger is GREAT!! Thank you.
> Dan


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## SilverFox

Hello Dan,

I don't think so. A high self discharge rate usually indicates separator damage inside the cell. A new cell is about the only thing that will fix that.

Tom


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## N162E

Mike abcd said:


> IMHO, I'd definitely discharge them first or better yet, condition them with the refresh mode a couple of cycles or until the reported capacity stabilizes.


I totally agree with this. All information concerning "Forming" or "Breaking in" of new batteries is based on them coming out of the package in a discharged state. I don't know that all new Nimh batteries are DOA and I do know for sure that the newer low self discharge ones are seeming to be coming out 75+ percent fully charged. My money says play it safe and discharge first



> It takes 12 hours at .1C to fully charge a fully discharged NIMH cell per Duracell. That's also what I found when I did a quick test. Anything beyond that is overcharging and overcharging, even at .1C, is not good for NiMH cells. A 16 hour charge at .1C is roughly a 30% overcharge and can be a LOT more if the cell isn't fully discharged beforehand. I've found quite a few new cells with substantial initial charge out of the wrapper.
> 
> I know popular wisdom is that new cells should be "formed" with a 16 hour .1C charge but I can't find any cell manufacturer who advises it.


From what I "READILY' found in the Duracell site they specified overnight charge. I did not see anything referring to initally forming the cell at any special rate.


> I also believe new cells require cycling and won't exhibit stable or full capacity on the first cycle. I've even seen poor cells that require 4-5 cycles such as the Lenmar junk. I just don't believe that you have to abuse them with overcharging based on my experience.
> 
> Running for my flameproof suite now...
> 
> From the FAQ.
> "*Using the CYCLE mode, why do I see a “0 mAh” capacity on the screen? What happened to the saved battery capacity?
> *
> A CYCLE is consisted of:
> Charge > 1 Hour Rest > Discharge > 1 Hour Rest (repeats for programmed number of times)
> The discharge capacity is saved into the memory at completion of discharge but cannot be reviewed until the cycle is completed (after the 1 hour rest). During the rest, a zero capacity is displayed. However, as soon as the rest is completed, you can use the “UP” and “DOWN” key to access the capacities saved in memory."
> 
> Ouch, I hope this gets modified in a future firmware. Sounds like a bug, sloppy programming or a very foolish design decision. I guess I'll be doing a lot of seperate charge and discharge cycles on mine instead of using the "Cycle" mode.


I concur with this totally, this is a flaw not a feature in the programming.


> Does anybody know if you can insert multiple cells at once and only have to set the parameters once like the BC-900? If not, I hope that also gets changed in a future firmware revision.


I mentioned this previously. Being to set custom profiles or just being able to adjust defaults here would go a long ways. Global settings per cycle could also go a long ways.


> Mike


Kudos and compliments to MahaPower and Mr. Chieu. We asked and they listened. This is essentially a design asked for and built for enthusiasts. This is a great Rev 1, I can't wait to see what is coming.


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## Thujone

+1 for bug [Not Feature]

This will be quite irritating. "I've got a cookie for you, you can have it in an hour" is not cool at all.



Mike abcd said:


> I still understand that as not being able to view the result of the LAST discharge cycle until 1 hour after the LAST discharge cycle completes.
> 
> That's just wrong. You have the capacity measured in the dischage test. Why wait an hour to provide it to the user? The rest period isn't going to change the result.
> 
> Mike


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## summerwind

Mike abcd said:


> mode.
> 
> Does anybody know if you can insert multiple cells at once and only have to set the parameters once like the BC-900? If not, I hope that also gets changed in a future firmware revision.
> 
> Mike


 
Mike, when you say multiple cells, do you mean with all having the same capacity rating?
i was thinking this as well, but then realized that one could charge different capacity cells and program each as required.
are you meaning that all slots should be programmed at the same time?


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## coppertrail

Content of post removed.


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## N162E

coppertrail said:


> WIth the BC-900, you insert all your cells, *then* plug in the AC Power cord. You then set the charge current and mode for all 4 cells.


Is this a new procedure? I've always put my batteries in with the BC-900 plugged and then set the charge current within 8 seconds. My BC-900s are always plugged in.

I checked the BC-900 manual and it specifically says that batteries are to be inserted after the charger is plugged into AC supply.


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## kitelights

N162E said:


> Is this a new procedure? I've always put my batteries in with the BC-900 plugged and then set the charge current within 8 seconds. My BC-900s are always plugged in.
> 
> I checked the BC-900 manual and it specifically says that batteries are to be inserted after the charger is plugged into AC supply.


ditto

My apologies for posting - this is a Maha MH-C9000 SUPPORT / FAQ Thread.


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## coppertrail

N162E said:


> Is this a new procedure? I've always put my batteries in with the BC-900 plugged and then set the charge current within 8 seconds. My BC-900s are always plugged in.
> 
> I checked the BC-900 manual and it specifically says that batteries are to be inserted after the charger is plugged into AC supply.


My apologies gentlemen, I stand corrected. The manual does mention plugging in the AC power before inserting the cells. I must have read the "insert cells before ac" on a forum somewhere and confused it with the manual's instructions.


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## Mike abcd

SilverFox said:


> Hello Mike,
> Got your flame proof suit on...


Sorry for the delay in replying. I don't know if you remember but we've had some discussions about a year back here and later at rcgroups. Been gone from here but the Cree XR-E got me back for a bit.

Any chance you could get a moderator to move these posts to another thread. I hate cluttering this one although it seems even existing questions aren't getting answered here.


> If you do a "forming" charge first, the capacity of the cell will stabilize pretty much on the first discharge cycle. With cells that have been"formed" you actually see very little change in capacity during cycling.


I frequently see capacity stabilize on the first fast charge cycle with decent cells. When it doesn't I suspect it's because of a short charge cycle due to a"false -dV/dt" peak as additional electrolyte gets "exposed"/"connected" causing what would be a short term drop in voltage. 

The only time I've seen capacity take more than 2 cycles to stabilize is with really bad cells like some Lenmar NoMem ones that I got with voltages well below 1.0 V. I suspect they were very old stock and would have taken multiple cycles even with your method.


> Duracell has excellent information. It has long been known that if we only charge to 90% of full capacity, keep the cells cool, and avoid prolonged trickle charging, the cells will last a lot longer. Unfortunately, they don't supply any data to back this up. Their cells are not advertised as being able to run for more cycles using their charging procedure, and if you follow it precisely, you will find that you loose around 10% in capacity.


I don't know if it's alwyas been there and we both missed it or it got recently added but they do give data now! Take a look at Section 6.2.6 Rate of Temperature Increase (dT/dt).
http://www.duracell.com/oem/Pdf/others/LithBull.pdf

The comparison only used a discharge to 70% and frankly I find the longevity increase disappointing in view of the loss in charged capacity assuming they used the 1/2 hour .1 C top off charge. Their data shows it takes 250 cycles for the useable capacity of the -dV/dt to drop below the dT/dt. I guess I'm going to stop being a fan of dT/dt charge termination. Suddenly made me worry that the C-9000 I have enroute was a bad purchase but then I remembered it uses a 1 hour .1 C top off charge which should result in about the same capacity as a -dV/dt termination would with a cycle life somewhere in between since the additional charge is being put in at a slower rate.


> Let's look at the 12 hour 0.1C charge. With cells that have been formed and cycled and in general are broken in, a 12 hour charge will get you within 95% of full capacity. This is charger dependent. Constant current chargers do better than pulsed chargers. 14 hours gives a little overcharge, but does a better job of redistributing the electrolyte within the cell.


I only ran one .1 C 120% test using a BC-900 but I definitely saw a full charge compared to a 1000 mA -dV/dt charge. I started with a 1000 mAH fast charge, 500 mA discharge and logged capacity. Then I made sure the cell was fully discharged using the 100 mA rate. I then charged at 200 mA. The BC-900 actually terminated the charge at 117% of the capacity previously measured. I then discharged it at 500 mA and then did another "fast charge check". The ".1C 120%" actually had the highest measured discharge capacity of the 3 cycles by a small amount. Seemed pretty convincing to me so I didn't repeat it. I will try again with the C-9000 although I'll be surprised it I see only 95% capacity. Even so, a .1C 12:30 charge would fully charge a FULLY DISCHARGED cell if you're right.


> 16 hours is considered a "standard" charge according to the battery testing standards. The battery manufacturers use the "standard" charge to rate the capacity of their cells. While they don't come out and directly say so, I suspect Duracell uses the "standard" charge to rate their cells as well.
> 
> You have to ask yourself, “If the cell is fully charged at 12 hours, and can be damaged by overcharging beyond that, why does the industry standard call for a 16 hour 0.1C charge?”


It may be a standard for rating capacity but I don't know of ANY manufacturer who advises using it for current NiMH cells. Do you? Sanyo even states "Overcharging shortens the life of the Twicell, and for this reason, low-rate charging is fundamentally not suitable". Energizer and Duracell also point out that overcharging at .1 C is bad. Of course, the issue with slow charging is that you can't avoid an overcharge without knowing the current charge state and the capacity. Fast charging allows relaible charge termination without knowing either. Slow charging doesn't.

I suspect the development of the standard dates back to the NiCad era where cells were far more tolerant of abuse. It's intended to max out the capacity for rating purposes. Current NiMH cells don't get damaged enough in a single cycle to make much of a difference in the capacity measurement and provide a strong impetus for manufacturers to change the standard. Standards can be a nightmare to update or replace so it lives on. That doesn't make it a good thing to do with current cells.


> Yes, the 16 hour charge does overcharge the cell. However, that little bit of overcharge seems to enable the cell to operate at its fullest potential right away. The next time you charge the cell, it will not develop hot spots, and if you use several cells in a battery pack, you find that they stay in balance better. The 16 hour charge also allows for better balancing of the cells within a battery pack. The alternative is to do several cycles.


I don't consider a 33% overcharge "a little bit" and typically it's far worse because few folks can properly fully discharge their cells first without over discharging them. IMHO, the average user would be far better off performing 2 fast charge cycles with a partial (>50%) discharge in between. It's also faster...
[/QUOTE]
In "normal" use, people won't observe the slight performance improvements that come from cycling, and no one wants to baby sit a "forming" charge. People would be outraged if the manufacturers insisted on them doing a forming charge prior to use. The people may even insist that the manufacturer do the forming charge at the factory before sending the cells out. Sanyo, and others, originally did this along with adding a few cycles to the cell before sending it out. Cost cutting has eliminated this step as being unnecessary for "normal" use.

There are some of us that are "performance" users. We measure run time down to the minute (and sometimes down to the second). We measure light intensity changes with a lux meter and are very interested in getting the best performance from our cells. We are also patient enough to do a 16 hour charge, and have the equipment to dial in the 0.1C charge rate. We also want "fully" charged cells in order to get every minute of run time we can from the charge.
[/QUOTE]
Tom, I don't know if I qualify as a "performance" user but I have an Extech light meter, a DMM with a PC interface, a LiON/LiPo charger that reports mAH delivered, a BC-900 and a LOT of retired chargers I accumulated over the last 20 years. I did my first run time tests about 15 years ago when I started using the first power hungry handheld GPS units available. I'd never log run time on an NiMH/alkaline app to the second as my high school Physics and Chemistry teachers made sure I respected significant digits by taking off credit for answering with too many digits but I do log tenths of a minute on LiPo r/c heli use where it's meaningful. 

I want max run time too but recognize that overcharging or discharging can cost dearly in life cycles. Of course that's far more true with LiOn and LiPo where a single cycle can ruin it.


> The abuse comes from extended trickle charging. A cell is going to be as full as it can get in 16 hours at 0.1C. If you let it continue to charge for a week, the electrolyte will start to dry up. If you continue the charge for a year, you will see a performance drop.


Outside of flagrant abuse, cells die a death of a thousand cuts. I prefer not to cut mine unless I get a meaningful return. I guess we should agree to disagree on whether a "forming charge" provides a "meaningful return" vs fast charging with proper termination.


> Duracell offers some interesting graphs. While they are not based on “standard” test parameters, they are very informative.


Are there any standards other than for capacity measurement? It does seem that most cycle life tests are done with fast charging and -dV/dt termination but I don't know if thats a standard. Seems like that's all Sanyo uses for life cycle testing.


> Let’s take a look at they cycle test data for an example. The standard cycle test calls for a 0.1C charge for 16 hours, followed by a 0.2C discharge to 0.9 – 1.0 volts. This is continued until the capacity of the cell is at less than 80% of its original capacity.


Any references to that "standard"?


> Duracell offers a cycle test graph showing the effects of cycle life with charging and discharging temperature. They charge at 0.25C for 3.2 hours. This gives you roughly a 75% full cell. They discharge at 0.25C for 2.4 hours. The interesting part is that they measure capacity every 50 cycles by charging at 0.33C for 5 hours followed by a 1.0C discharge to 1.0 volts. The 0.33C charge for 5 hours works out to a 165% charge. I find it interesting that this is actually a higher overcharge than charging 16 hours at a 0.1C rate. It is also interesting that charging at a higher charge rate is more efficient, so it is a significant overcharge. To get the same results as charging for 16 hours at 0.1C when charging at 0.33C, you only need to charge for around 4 hours.
> 
> 
> 
> The charge/discharge is providing 133% charge input so the cell gets fully charged as long as it starts out that way. The graph doesn't show the number of cycles, only the "% cycle life". To me, it just looks like they wanted to accelerate the testing to determine the relative effect of temperature and hence were willing to accept reduced cycle life. Personally I think the assumption that the charge methadology doesn't affect the relative effects differently with temperature questionable.
> 
> I actually did 2 cycles on four Energizer 2500s to check your contention that fast charging was significantly more efficient. The results on the BC-900 were inconsistent so I'll call it inconclusive but seemed to lean in the direction of fast charging being less efficient. As charge in vs tested capacity, I got 125%, 127%, 124%, 126%, 120%, 122%, 115%, 118%. I might try it again with the C-9000 out of curiousity.
> 
> 
> 
> Fortunately, batteries handle a reasonable amount of abuse and still work well. Duracell offers some excellent advice, and looking at it from a consumers point of view, I agree with it. However, when I want peak performance from my cells, I will consider giving up some “longevity” for improved performance.
> 
> 
> 
> I fully agree with that. We just appear to disagree on whether a "16 hour .1C forming" overcharge offers any performance benefits that can't be attained with less effect on longevity. As a single one time event, it's probably moot but I see folks using that as a standard charge technique on cells and packs that are only partially discharged. That kind of abuse costs dearly in cycle life with no benefits at all IMHO.
> 
> BTW, I first stumbled in here looking for battery testing info and have found your testing among the best I've ever found for NiMH/LiON. I sincerely appreciate your contributions. Frankly it's what usually brings me back
> here as I'm not a true flashaholic although most folks who know me would
> think so. I won't but a light unless I have a high expectation that it fills a need I have for a size*runtime*brightness appreciably better than something I already have hence my current high interest in Cree XR-E and
> LiON to feed them. I have gotten pretty addicted to r/c helis though ;-)
> 
> Mike
> 
> PS Can we start a new thread if you want to continue this? I suspect a moderator might respond better to a request from you to move our posts than an unknown member like me.
> 
> Click to expand...
Click to expand...


----------



## EngrPaul

I got mine today.

Even though I read the manual fully, I didn't realize that you had to program each bay. I thought that I could insert 4 batteries quickly and set one program for all of them.

Secondly, I didn't know what the optimum charge rate would be, assuming one is not in a hurry and simply wants to have best performance. It clearly stated the optimum discharge rate, but not an optimum charge rate. It gives an acceptable range (0.33C-1.0C) but doesn't really tell you which one is best.

So I referred back to a Duracell NiMH paper I had on PDF. It said:

_Duracell recommends a three-step procedure that provides
a means of rapidly charging a nickel-metal hydride
battery to full charge without excessive overcharging or
exposure to high temperatures. The steps in sequential
order are:
1) Charge at the 1C rate, terminated by using
dT/dt = 1°C(1.8°F) /minute.
2) Apply a C/10 top-up charge, terminated by
a timer after 1/2 hour of charge.
3) Apply a maintenance charge of indefinite
duration at C/300 rate._

So I decided to use C=1.0 and round down to the next lower 0.1A. 

I re-read the manual and saw that Powerex follows Duracell's guidelines for top-off and maintenance charges at the end of the cycle.

So these are my two requests for the manual or FAQ: (1) Point out that each bay needs programmed individually, and (2) define what the optimal charge rate is, not just a range.


----------



## EngrPaul

Curious_character said:


> Hm, Maha recommends charging at no less than 0.33C, and says the new charger supports batteries up to 20,000 mAh. I conclude then that it's capable of a charge current of 6.67 amps. Impressive!
> 
> c_c


 
The input is rated 12V at 2.0 A. With 24W total input, the maximum current it could supply to batteries is about 15A. This would limit you to two batteries at a time.


----------



## EvilLithiumMan

Is it too early to start hacking the MH-C9000? You know, any undocumented features accessed only by undocumented key presses? I.E., if you power up the C9000, you'll see it go through a diagnostic check and the display counts down from 9.9.9.9. to 0.0.0.0. and then shuts off. However, if you power up the C9000 while holding down the 'UP' button, you'll see it do something a little different once the display gets to 0.0.0.0.

Am I looking for anything specific? Well, not really. But if there was a way to program all four slots at once, it'd be nice to know about it.


----------



## coppertrail

Last night I put some Sanyo 2700s through a break-in cycle. About 10 min ago, the power in my home went out for about 1 second and then came back on. 

I looked at the charger and it had reset itself, displaying "charge" mode at the default rate. 

Based on this experience, it seems that the following is true: If the power goes out, even momentarily, the charger resets itself to the default mode. I understand this could be alleviated by plugging the unit into a UPS system. But, if not, and one is 36 hours into a "Break In" cycle, all that will be lost, and one must start out from the beginning?


----------



## wptski

I've been reading some of the posts of users that received their C9000's. I got my two yesterday. I think that this is going to be one of the most complex operating chargers so far.

I used some almost new 1000mAh PowerEx AAA cells. I charged two and discharged two on one unit. Using the second unit I then took the discharged pair and inserted them into slots 1/4, charging at 1A and charged two more that came out of my cordless mouse at 1A also in slots 2/3.

I took a extended nap.  I didn't note the time that I started the charging. All were done with slots 1/4 charging for just over an hour for just over 1Ah and slots 2/3 charging for 30-35 min. for just over .5Ah. So slots 2/3 finished way ahead of the others. Makes sense as they weren't depleted. Ah! Looking at the thermal image, slots 2/3 are warmer than 1/4 and appear to be still charging, I assume this the topoff charge. But why didn't it topoff slots 1/4? Looks like this charger doesn't always do a topoff charge for some reason! There's probably some real complex answer for this.

Remember that the center two slots showed DONE in half the time compared to the two outside slots.

BTW: Happy Hoildays!!!








[/


----------



## moldyoldy

Hi Bill, 

FWIW, for years I have noted that cells that are charged from a full discharge do not heat up as much at the end of a charge compared to cells that are charged from, say, about a half discharge. IOW, the cells that charged from a full discharge were cooler at the end than cells that were charged from about 1/2 discharge. I am not sure why, but it has happened often enough with multiple chargers and cells that I am rather confident of the situation. 

Also, it has sort of been a test of chargers to take a cell that just finished a charge in one charger and insert it into another charger to see if the second charger will probably determine end of charge. and yes, the cells get hot!

Tim


----------



## moldyoldy

By the way Bill, I am thoroughly envious of your thermal imaging system!!! I still sort of putz around with thermocouples that are seriously deficient in consistency for temp readings. Contact sensing is always a question if no heat sink compound is used.

Tim


----------



## Lonely Raven

Odd question that I figure I know the answer to.

In another thread it was mentioned that the MH-C9000 could charge any of the more common rechargable batteries...IE C and D cells. 

But will it be able to handle the MAHA 9V 300 mAh NiMH Rechargeable Battery, or does the charger not have the capacity to do that?

I use a lot of 9v in my guitar gear, and some other odds and ends around the apartment. I'm considering switching to rechargable, and I'm not looking forward to buying another charger...especially after seeing how fantastic the C9000 is!


----------



## wptski

Lonely Raven said:


> Odd question that I figure I know the answer to.
> 
> In another thread it was mentioned that the MH-C9000 could charge any of the more common rechargable batteries...IE C and D cells.
> 
> But will it be able to handle the MAHA 9V 300 mAh NiMH Rechargeable Battery, or does the charger not have the capacity to do that?
> 
> I use a lot of 9v in my guitar gear, and some other odds and ends around the apartment. I'm considering switching to rechargable, and I'm not looking forward to buying another charger...especially after seeing how fantastic the C9000 is!


It won't do 9V batteries, just AA/AAA's!


----------



## wptski

moldyoldy said:


> Hi Bill,
> 
> FWIW, for years I have noted that cells that are charged from a full discharge do not heat up as much at the end of a charge compared to cells that are charged from, say, about a half discharge. IOW, the cells that charged from a full discharge were cooler at the end than cells that were charged from about 1/2 discharge. I am not sure why, but it has happened often enough with multiple chargers and cells that I am rather confident of the situation.
> 
> Also, it has sort of been a test of chargers to take a cell that just finished a charge in one charger and insert it into another charger to see if the second charger will probably determine end of charge. and yes, the cells get hot!
> 
> Tim


Tim:

Hmmm, I've never noticed that but will look into it and maybe start a new thread. I hope that this is the answered to my above question.

P.S. Don't be envious. You don't know how many sleepness nights I spent before the purchase although I got a very, very good deal!


----------



## EvilLithiumMan

wptski said:


> I've been reading some of the posts of users that received their C9000's. I got my two yesterday. I think that this is going to be one of the most complex operating chargers so far.
> 
> I used some almost new 1000mAh PowerEx AAA cells. I charged two and discharged two on one unit. Using the second unit I then took the discharged pair and inserted them into slots 1/4, charging at 1A and charged two more that came out of my cordless mouse at 1A also in slots 2/3.
> 
> I took a extended nap.  I didn't note the time that I started the charging. All were done with slots 1/4 charging for just over an hour for just over 1Ah and slots 2/3 charging for 30-35 min. for just over .5Ah. So slots 2/3 finished way ahead of the others. Makes sense as they weren't depleted. Ah! Looking at the thermal image, slots 2/3 are warmer than 1/4 and appear to be still charging, I assume this the topoff charge. But why didn't it topoff slots 1/4? Looks like this charger doesn't always do a topoff charge for some reason! There's probably some real complex answer for this.
> 
> Remember that the center two slots showed DONE in half the time compared to the two outside slots.
> 
> BTW: Happy Hoildays!!!
> 
> 
> 
> 
> 
> 
> 
> [/




Slots 2 & 3 are both nested between two other cells. Slots 1 & 4 have a cell to one side of them, but ambient air on the other side. How does one know the cooler running outer slots aren't that way because of this?

(Way cool device, by the way! Does it work on sensitive body parts?)


----------



## RobSpook

EvilLithiumMan said:


> (Way cool device, by the way! Does it work on sensitive body parts?)



LMAO :naughty::naughty::naughty:


----------



## wptski

EvilLithiumMan said:


> Slots 2 & 3 are both nested between two other cells. Slots 1 & 4 have a cell to one side of them, but ambient air on the other side. How does one know the cooler running outer slots aren't that way because of this?
> 
> (Way cool device, by the way! Does it work on sensitive body parts?)


I thought of that but I'd think that the center or between the two inner cells would be coller but their not. I need to repeat the test again with two cells using slots further away from eachother.

Yes, it does! Like your nose or toes would be cooler compared to your face or foot. I'm not going any further than that!


----------



## EngrPaul

coppertrail said:


> Last night I put some Sanyo 2700s through a break-in cycle. About 10 min ago, the power in my home went out for about 1 second and then came back on.
> 
> I looked at the charger and it had reset itself, displaying "charge" mode at the default rate.
> 
> Based on this experience, it seems that the following is true: If the power goes out, even momentarily, the charger resets itself to the default mode. I understand this could be alleviated by plugging the unit into a UPS system. But, if not, and one is 36 hours into a "Break In" cycle, all that will be lost, and one must start out from the beginning?


 
I am concerned about charging cells < 1000 mA*h capacity if a power failure occurs. The manual states in large letters that "Charging... above 1.0C is not recommended". This default charging rate would be higher than allowed if a power failure occurred.

I've already had problems with lack of termination with AAA cells. Just imagine doing a break-in cycle, and returning to find the cells have been charge at over 1.0C, and as far as 20,000 mA*h... just because of a momentary power failure.

Please tell me NiMH batteries can't explode, or spray acid.


----------



## coppertrail

Paul - 

I just posted this concern in the main C9000 thread. I may purchase the following UPS unit this evening:

APC Battery Backup 350VA 200 Watt UPS


PC protection for office or home

350VA, 200 watts, 8 outlets with 2 spaced for large adapters

4 battery back up, 4 surge protection only

USB connection, RJ-11 protection

It's $40 @ Office Max. Not sure how much runtime I'll get with only the MH-C9000 plugged in.


----------



## BVH

I realize that not every juristiction is the same, but I find that 99% our "power outages" here locally, are less than a second or two - typically only as much time as it takes for the power company's back-up systems to switch over to another source. But long enough that it would cause the problem mentioned above. In my case, I'm just looking to have UP for the transition time so a very small UPS is more than enough. You could probably find a few other gadgets to hook into it that you wouldn't normally have backed up.


----------



## coppertrail

BVH said:


> I realize that not every juristiction is the same, but I find that 99% our "power outages" here locally, are less than a second or two - typically only as much time as it takes for the power company's back-up systems to switch over to another source. But long enough that it would cause the problem mentioned above. In my case, I'm just looking to have UP for the transition time so a very small UPS is more than enough. You could probably find a few other gadgets to hook into it that you wouldn't normally have backed up.


Thanks BVH, I'll be picking up one of these tonight.


----------



## BVH

Just another thought. Many UPS's tout they also provide power conditioning/surge suppression etc. Some of the higher priced, larger units probably do provide excellent protection in addition to the backed-up power. If you're buying a small UPS with little or no protection, don't forget to use a good surge protector in addition to the UPS to protect your connected equipment. Look closely at the specs to know what you're getting.


----------



## EngrPaul

*Here's a thought.*

Q: Why doesn't the charger remember it's settings? 
A: Because the power is interrupted.

Q: What do manufacturers do to keep devices remembering their settings when the power goes off?
A: They install low-drain battery-backups.

Q: What are those little cylinders you put in a battery charger?
A: Batteries.

Q: Well, if there are batteries in the device, couldn't it use them to remember the settings?
A:


----------



## RobSpook

Well, why not just use a few simple capacitors? Cheap eh?


----------



## EvilLithiumMan

BVH brings up a good point. There are two general classifications UPS, "online" and "offline". With an online UPS, the inverter runs 100% of the time, so when input power fails, there is no unterruption of the output, the inverter was already running. But an offline UPS uses a relay or electronic switch to connect the input power to it's outlets when input power is present. When input power fails, there is a response time when the UPS logic has to determine the input has failed, the inverter must be switched on and the output connected to the inverter.

This "switchover" time is usually in the range of 10 to 40 milliseconds, usually a very safe range for computer power supplies. But I doubt there is any "headroom" in the AC power brick/wall wart that is used for our chargers.

Needless to say, the online UPS is more expensive, as the inverter is running all the time. The offline approach is what lower end UPS's usually use. And their spec. sheet should state what the dropout time is.


----------



## N162E

wptski said:


> P.S. Don't be envious. You don't know how many sleepness nights I spent before the purchase although I got a very, very good deal!


OK Bill, I give. I am envious too. I'll be the one to ask. What did you take that thermal image with? I want one.


----------



## EngrPaul

The input is 12VDC. The device will run off a vehicle power outlet. You could consider using a 12VDC rechargeable battery in parallel to the input


----------



## BVH

EMan, what is the maximum millisecond response time people should look for in an "offline" UPS to be safe for this use?


----------



## Mike abcd

Firmware can easily handle this. They seem to have a power on start up routine from the posts I've seen. If it finds cells inserted in that check, it should flash the display and NOT attempt to charge the cells. Just sit there until the cells are removed or the user presses a button.

No additional hardware required just some better thought out firmware. To be fair, it's a common flaw with chargers. One hopes for improvements though particularly when all it takes is some common sense.

Mike


----------



## wptski

N162E said:


> OK Bill, I give. I am envious too. I'll be the one to ask. What did you take that thermal image with? I want one.


Fred:

A Fluke Ti30.


----------



## willchueh

Mike,

This is an excellent suggestion. I'll pass it on to the development team!

Thanks again.

William




Mike abcd said:


> Firmware can easily handle this. They seem to have a power on start up routine from the posts I've seen. If it finds cells inserted in that check, it should flash the display and NOT attempt to charge the cells. Just sit there until the cells are removed or the user presses a button.


----------



## BVH

William, will firmware upgrades be available at some point in the future? (understanding, of course, that the unit will have to be sent back for the flash) Will future chargers, maybe even later versions of this one, have end user flash capability via USB port as others have inquired here on CPF?


----------



## EvilLithiumMan

"Better thought out firmware" is exactly right. Take the following scenario - the charger is charging a cell at a high rate, let's say 2000ma. The charger will terminate when it senses -dv/dt. Assume the cell is 10% charged and then the power goes out for 5 seconds. During that 5 second lull, the cell's voltage will drop. When power returns, the firmware is going to see a lower cell voltage. We know this isn't because of a true -dv/dt situation, but if the firmware isn't designed properly, it will terminate the charge because it sensed a -dv/dt. I wouldn't want that.

BHV - I have a line dropout generator. I am in the process of setting it up now and I will test both the MH-C9000 and BC-900 to see what they can tolerate.


----------



## Mike abcd

EvilLithiumMan said:


> "Better thought out firmware" is exactly right. Take the following scenario - the charger is charging a cell at a high rate, let's say 2000ma. The charger will terminate when it senses -dv/dt. Assume the cell is 10% charged and then the power goes out for 5 seconds. During that 5 second lull, the cell's voltage will drop. When power returns, the firmware is going to see a lower cell voltage. We know this isn't because of a true -dv/dt situation, but if the firmware isn't designed properly, it will terminate the charge because it sensed a -dv/dt. I wouldn't want that.
> ...



I'd MUCH rather have that than ruined cells or worse because it started charging fully charged cells again...

The ideal is that it "remembers" what it was doing but that takes extra hardware and that costs money. My suggestion is simple to implement, costs nothing in hardware and is SAFE. Someone else might come up with something better but I can definitely live with having to restart charging or discharging as long as I don't have ruined cells or worse.

Mike


----------



## willchueh

EvilLithiumMan,

MH-C9000 does not have NVRAM so it is not possible to remember data while powered off.

William




EvilLithiumMan said:


> "Better thought out firmware" is exactly right. Take the following scenario - the charger is charging a cell at a high rate, let's say 2000ma. The charger will terminate when it senses -dv/dt. Assume the cell is 10% charged and then the power goes out for 5 seconds. During that 5 second lull, the cell's voltage will drop. When power returns, the firmware is going to see a lower cell voltage. We know this isn't because of a true -dv/dt situation, but if the firmware isn't designed properly, it will terminate the charge because it sensed a -dv/dt. I wouldn't want that.


----------



## Mike abcd

willchueh said:


> Mike,
> 
> This is an excellent suggestion. I'll pass it on to the development team!
> 
> Thanks again.
> 
> William



Glad to see you're open to suggestions for improvements.

Please also pass the other suggestions already posted on to the development team.

- If multiple cells are inserted within 5 seconds, the charger should flash the cell indicators of those slots at the same time and only require setting the parameters once for all the cells that were inserted at the same time. If a user wants separate settings, he should be forced to insert each cell individually and set its parameters.

- When performing one or more refresh cyles, the result of the LAST discharge cycle should be available as soon as it completes. The user should NOT have to wait until the end of the one hour rest cycle to see the result. It would be even better if you can check the amount discharged at any time during the discharge cycle. Progress checks are frequently useful.

Mike


----------



## moldyoldy

just some data on power lines for your rumination.  In case you don't think that you need a UPS......

A common feeder from a power station is 13800VAC 3 phase @ 4000-5000Amps in a Y configuration. If a phase fault occurs, a common high-voltage vacuum breaker will break the circuit w/in 10-15 cycles. It takes about 5 cycles for the breaker to stabilize after opening. The average breaker is set to reclose in 5 seconds or so. That constitutes the two "bang.....bang" hits that happen when a main feeder goes out. Spectacular if you should happen to be anywhere close - hopefully not! If the line is still in fault, the breaker reopens and stays open. Human intervention is then required.

Another note about feeder faults. If one phase shorts to ground, the next close of the breaker will usually find another phase shorted to ground. Suffice to say that with currents of the magnitude that will flow to ground during a short-circuit condition on a feeder line will cause signficant neutral and ground currents to flow. At that voltage, the ground is a nice high-wattage resistor. I will let you do the multiplication..... The end result is that both the neutral and the ground in the area will NOT be at zero volts. What that voltage could be is dependent on how close your sensitive equipment is to the fault or the power station. A mile or two at those voltages and currents is not much protection if the current should happen to flow on the surface of the ground!

As for the typical UPS, I happen to have the APC Backup UPS ES 750 with tel and coax protection. equivalent to 450watts. The transfer time to battery in a failure is listed as 6 milliseconds typical and 10 milliseconds maximum. In general, the company I work for has good experiences with the APC units in comm closets. Besides my own unit, I installed APC UPS units at a couple churches - no call backs at all, and yes, they are in use.
There are other good UPSs, but as was pointed out above, pay attention to the noise reduction, not just the spike/surge protection!

Tim


----------



## jtr1962

Since nobody asked I'm curious about the LEDs used in the backlighting. Are they designed to remain bright after thousands of hours of use? Typically, 5mm and other types of small LEDs will have a useful life of a few thousand hours unless underdriven. Can we assume that Maha put as much thought into the backlight as it did into the rest of the charger? I really like the charger so far. My only real concern at this point is the long term usefulness of the backlight.


----------



## Curious_character

I got my MH-C9000 today, and it's nearing the end of the discharge part of its first refresh/analyze cycle with 4 2300 mAh cells. I set the charge rate to 1 A and discharge to 500 mA. The cells are now at about 1.10 - 1.15 volts, and I see that the discharge current on one station has dropped to about 300 mA and is dropping fairly fast. Another is at about 420 mA and dropping. The lowest voltage cell is still near 500 mA.

At what part of the discharge cycle does the discharge current begin decreasing? Does the charger use the actual current in its calculation of battery capacity, or does it assume that the discharge current is what I specified?

c_c


----------



## EngrPaul

jtr1962 said:


> Since nobody asked I'm curious about the LEDs used in the backlighting. Are they designed to remain bright after thousands of hours of use? Typically, 5mm and other types of small LEDs will have a useful life of a few thousand hours unless underdriven. Can we assume that Maha put as much thought into the backlight as it did into the rest of the charger? I really like the charger so far. My only real concern at this point is the long term usefulness of the backlight.


 
LED's will dim over time. The charger display is generously sized and extremely readable, so even at 20% brightness at end-of-life it will be fine.

I'm more concerned about my fading eyesight in the next few years... as I will start needing reading glasses like all my peers... :lolsign:


----------



## moldyoldy

EngrPaul - If reading glasses is all you will need, you are uniquely blessed! 

My Aunt lived in Fargo ND in her own house for many years. She had a framed needle point hanging on the wall, the sole content of which was this text - "Growing Old Ain't for Sissies". She lived to 101 and was one of the very early women in the US who had a full 4yr college degree around the turn of the century. 

I myself have historically been physically active with no permanent prescription medicine, not overweight, etc. However in the last year I have had 3 MRIs, 1 CATSCAN, and one cataract surgery. I am being humbled....

Tim


----------



## danidentity

Hey guys, this is my first post here. I picked up the MH-C9000 from TD.

I'm currently doing a *discharge *on a battery just to test it out. The displayed "MAH" value is steadily *increasing *while the battery is discharging. Is this the correct behavior?


----------



## EngrPaul

danidentity said:


> Hey guys, this is my first post here. I picked up the MH-C9000 from TD.
> 
> I'm currently doing a *discharge *on a battery just to test it out. The displayed "MAH" value is steadily *increasing *while the battery is discharging. Is this the correct behavior?


 
Yes, it's accumulating the energy the battery is expending. At the end of the cycle, the final number represents the capacity the battery had before you started discharging it. The discharge terminates when the battery reaches 1.00 Volt. If you had completely charged the battery before doing the discharge, then the final MAH number you get should be around the MAH capacity printed on the wrapper of the cell.


----------



## EngrPaul

William,

Can you provide a Q/A for the following question:

*Some of my batteries take longer to charge or discharge than other batteries of the same brand and capacity. Why is this the case, and what does it mean?*

I saw somebody else mention the same question.

Personally, I'm noticing that cell "C" (of my 4 marked A-B-C-D) takes a very long time to discharge, regardless what slot it is put in. But the reported capacity is next to the best. 

Is the impedance or internal resistance of this battery probably higher than the others? Can the capacity be good but the battery be bad?

Thanks in advance.


----------



## EngrPaul

*Duplicate Post*

[Deleted]


----------



## EngrPaul

May I elaborate on the discharge question.

While performing a *break-in * on 4 batteries simultaneously, several of my cells were already past the discharge, rest, and several hours into charging. Cell "C" took 9.3 hours to discharge! The final capacity was 741 mA*h (battery rated at 850). This was mid-capacity of the 4.

Near the end of the cycle, it was loafing around a few mA. What I don't understand is why the discharge is 0.2C, but the load on the battery tapers down to around 0.005C at 1.01 volts? 

Shouldn't it be a flat 0.2C of the battery's *overall capacity*... or is the discharge regimen 0.2C of the *remaining capacity*?


----------



## willchueh

EngrPaul said:


> While performing a break-in on 4 batteries simultaneously, several of my cells were already past the discharge, rest, and several hours into charging. Cell "C" took 9.3 hours to discharge. The final capacity was 741



EngrPaul, 

I think I've a good explanation for you. During both charging and discharging, the voltage is read "offline" which means they are taken with the current off. 

Say your battery has a higher than usual resistance. When the current is on, it might cause the battery voltage to drop (treating the battery as a virtual resistor - this is really not the case it's best simulated by a resistor and capacitor in parallel). This voltage drop can cause the charger to unable to pull the set current as the voltage becomes too low (the circuit is only designed to reach set current when battery voltage is >0.9V). 

The Good news is capacity calculation is always made with the "real" current. The software does an integration of current with respect to time every two sceonds. So your capacity reading is still accurate. 

William


----------



## EngrPaul

That's helpful.

I suppose since I'm using the cell in a low-drain application (optical wireless mouse), the additional internal resistance probably doesn't show up as a problem during use.


----------



## willchueh

The discharge current, in theory, should be constant. See post #67 for more info.


----------



## wptski

This is a follow to a post of mine above.

I took four discharged 2.3Ah Duracells and set them up to charge at 2A. Slot#3 finished first for [email protected] min, then came Slot#2 for [email protected] min and I took the following image.







Slot#4 came in for [email protected] min and then Slot#[email protected] min and I took the following image.






After 1 ½ hrs I took the following image. Slots#2/3 are still warmer than Slots#1/4.






The following is from another thread. The cells are in the same slots that they were charged in. The slots that finished first first above, finished last here.
>>>>
I just charged four 2.3Ah Duracells at 2A, allowed to cool and reinserted them into the same slots again at 2A.

Slot#1 = [email protected] min
Slot#2 = [email protected] min
Slot#3 = [email protected] min
Slot#4 = [email protected] min
>>>>
Later on I took the following image in which you can see the there is a hot under the center two slots. Seems like this is affecting the charging of in the center two slots. Only a C/D will prove how much or even better if something else than the C9000 was used.


----------



## EngrPaul

Are those little cool spots at the bottom the thermocouples?


----------



## wptski

EngrPaul said:


> Are those little cool spots at the bottom the thermocouples?


That is the metal temperature sensor wraped over the edge of the pocket. It looks that way because it's shinny. Stuff that reflects is a problem with IR imaging. I'm new to this and learning. 

EDIT:

You notice that it's red right around it because it's reflecting its heat into the surrounding plastic but reflects back to the imager as blue or cold.

That last image is much clearer too as I was inside the minimal distance on the others! Still learning.


----------



## N162E

wptski said:


> That last image is much clearer too as I was inside the minimal distance on the others! Still learning.


Really good stuff there Bill. I'd say for a few days experience you are learning real quick. I think you are going to come up with a lot of real useful info in short order. A cute parlor trick is to point it into a group of people, see who has a fever and tell them you hope they feel better.


----------



## wptski

N162E said:


> Really good stuff there Bill. I'd say for a few days experience you are learning real quick. I think you are going to come up with a lot of real useful info in short order. A cute parlor trick is to point it into a group of people, see who has a fever and tell them you hope they feel better.


Fred:

I had it in hand while taking the trash out tonight and took some images of my house. I think that I'll look into that new battery operated caulking gun! :lolsign:


----------



## Thujone

Well just starting using mine. And the power supply is bad. Works for a few moments then shuts off. If i hit it with my multimeter the voltage has fallen off to 2.4 volts. If i leave it unplugged for a few minutes and plug it back in it recovers to 12v till i apply load. Major bummer. Is this something to take up here? Or should I contact Thomson Dist.?


----------



## wptski

Thujone said:


> Well just starting using mine. And the power supply is bad. Works for a few moments then shuts off. If i hit it with my multimeter the voltage has fallen off to 2.4 volts. If i leave it unplugged for a few minutes and plug it back in it recovers to 12v till i apply load. Major bummer. Is this something to take up here? Or should I contact Thomson Dist.?


Any way to check the current that the charger is drawing? Could be the charger too unless you another power supply to try??


----------



## coppertrail

Contact Thomas-Distributing since you just purchased it.


----------



## Thujone

wptski said:


> Any way to check the current that the charger is drawing? Could be the charger too unless you another power supply to try??



Charger is working on my 12v 25amp supply as we speak. Will check on it again in a while but worked while I was in the room.

Edit: Still working. So it is just a case of a power supply that cant supply any current... Hopefully Maha will ship a replacement. I do not want to RMA the whole thing...


----------



## wptski

Thujone said:


> Charger is working on my 12v 25amp supply as we speak. Will check on it again in a while but worked while I was in the room.


Well, I'd conatct T/D but I'm not sure if they send just the power supply.


----------



## B612

The backlight not having an off switch is easily solved and I can live with the barely audible click on the C808M but is the high pitch pulsing whine on the c9000 when charging normal?

it can be heard at least 3 metres away with a gale blowing outside or am I just the youngest person to purchase one and the only one that can still hear it.

What is the power usage when there are no batteries inserted both from the mains adaptor and the charger (drain fron a 12v battery) if you please?
The mains adapter plugged into the charger doesn't register on my power meter but they are not renowned for their accuracy it's really nice if it is below 1w at least one manufacturer is not wasting my electricity unnecessarily.:goodjob:


----------



## wptski

B612 said:


> The backlight not having an off switch is easily solved and I can live with the barely audible click on the C808M but is the high pitch pulsing whine on the c9000 when charging normal?
> 
> it can be heard at least 3 metres away with a gale blowing outside or am I just the youngest person to purchase one and the only one that can still hear it.
> 
> What is the power usage when there are no batteries inserted both from the mains adaptor and the charger (drain fron a 12v battery) if you please?
> The mains adapter plugged into the charger doesn't register on my power meter but they are not renowned for their accuracy it's really nice if it is below 1w at least one manufacturer is not wasting my electricity unnecessarily.:goodjob:


I made to room quiet and could hear the clicking at .6M and the high pitched whine at .3M. Although I wear hearing protection, working 40 years in a noisey factory inviroment doesn't help!


----------



## Carbo

I've run my charger through one complete Break-In cycle, and am now in the midst of a second. I haven't heard a peep at all since plugging the unit in.


----------



## BVH

I have very good hearing for all frequencies and putting my ear directly on each of my two chargers results in absolute quiet. I wouldn't want to put up with a hum of any sort as you describe it.


----------



## wptski

My automotive code scanner whines and so does my Fluke scopemeter. No big deal to me! Other chargers do the same also.


----------



## willchueh

Thujone,

Sorry to hear about that. Just call our customer support center at 1-800-376-9992. They'll ship you a free replacement and collect the defective one (if needed) back at Maha' cost.

William




Thujone said:


> Well just starting using mine. And the power supply is bad. Works for a few moments then shuts off. If i hit it with my multimeter the voltage has fallen off to 2.4 volts. If i leave it unplugged for a few minutes and plug it back in it recovers to 12v till i apply load. Major bummer. Is this something to take up here? Or should I contact Thomson Dist.?


----------



## willchueh

B612 said:


> What is the power usage when there are no batteries inserted both from the mains adaptor and the charger (drain fron a 12v battery) if you please?
> The mains adapter plugged into the charger doesn't register on my power meter but they are not renowned for their accuracy it's really nice if it is below 1w at least one manufacturer is not wasting my electricity unnecessarily.:goodjob:



The standby drain @ 12V is about 70mA. 

William


----------



## Lonely Raven

Oh man! I'm glad I'm not the only one to hear that pulsing. It was driving me nuts!

For being 35, I still have unusually good high frequency hearing, and I hear this. *Meep* pause *Meep* pause *Meep* when I was charging some cells at 1500ma.






B612 said:


> The backlight not having an off switch is easily solved and I can live with the barely audible click on the C808M but is the high pitch pulsing whine on the c9000 when charging normal?
> 
> it can be heard at least 3 metres away with a gale blowing outside or am I just the youngest person to purchase one and the only one that can still hear it.
> 
> What is the power usage when there are no batteries inserted both from the mains adaptor and the charger (drain fron a 12v battery) if you please?
> The mains adapter plugged into the charger doesn't register on my power meter but they are not renowned for their accuracy it's really nice if it is below 1w at least one manufacturer is not wasting my electricity unnecessarily.:goodjob:


----------



## bcwang

B612 said:


> The backlight not having an off switch is easily solved and I can live with the barely audible click on the C808M but is the high pitch pulsing whine on the c9000 when charging normal?
> 
> it can be heard at least 3 metres away with a gale blowing outside or am I just the youngest person to purchase one and the only one that can still hear it.
> 
> What is the power usage when there are no batteries inserted both from the mains adaptor and the charger (drain fron a 12v battery) if you please?
> The mains adapter plugged into the charger doesn't register on my power meter but they are not renowned for their accuracy it's really nice if it is below 1w at least one manufacturer is not wasting my electricity unnecessarily.:goodjob:



I know what you mean, the high pitched whine is driving me crazy, I'm about a meter away from the charger when I'm on my computer. It's surprising that some that claim to have no hearing loss can't hear it, unless there are variances among the units. I should compare it to my c777plus-II and see which one is louder. At least William says this is a normal noise from one of the components so it's not defective.


----------



## BVH

I think there are variances between units. I've been hearing tested as better than average throughout the frequency ranges. I can hear wall warts at night from 20 - 30 feet away but there's nothing emanating from my 2 units.


----------



## Mike abcd

Has anybody seen the C-9000 do a "top off charge" as mentioned in the FAQ? I'd expect to see that following a charge termination on delta temperature but not if it terminated on -dV/dt.

I haven't seen it do that yet and I've been doing a lot of charge cycles and trying to monitor it fairly closely.

I was expecting dT/dt to be the normal charge termination since it was listed as a feature and should normally happen before -dV/dt.

Mike


----------



## EngrPaul

Hi Mike,

I have been wondering the same thing. I only goes directly to "Done" for me.

Paul


----------



## wptski

Mike abcd said:


> Has anybody seen the C-9000 do a "top off charge" as mentioned in the FAQ? I'd expect to see that following a charge termination on delta temperature but not if it terminated on -dV/dt.
> 
> I haven't seen it do that yet and I've been doing a lot of charge cycles and trying to monitor it fairly closely.
> 
> I was expecting dT/dt to be the normal charge termination since it was listed as a feature and should normally happen before -dV/dt.
> 
> Mike


Mike:

I just put a scope on one of my C9000 today. I just check on the graph and it just showed DONE and had to terminate by -DeltaV because it's connected outside the charger. It's barely warmed the 1.8Ah cells at 1A rate anyway. It's showing 160ma topoff rate.

PWM ON portion of the signal is rather noisey too. I have a pair of current probes that don't read exactly the same but close and I'm assuming that the noise/hash is causing one to read over 200ma lower than the other one!


----------



## dekelsey61

Paul+Mike, I don't believe you will see the charger go into top off charge. Mine has never said that in the week I have had it. It is the same thing as the trickle charge. You never see the charger go into that mode. We have to believe that when the DONE comes on for 1hour after that it is in the top off mode then the trickle charge begins.
Dan


----------



## EngrPaul

dekelsey61 said:


> Paul+Mike, I don't believe you will see the charger go into top off charge. Mine has never said that in the week I have had it. It is the same thing as the trickle charge. You never see the charger go into that mode. We have to believe that when the DONE comes on for 1hour after that it is in the top off mode then the trickle charge begins.
> Dan


 
This would be really nice to know.

But to have it display "DONE" when it really isn't? Kinda defies logic, wouldn't you say? :laughing:


----------



## wptski

EngrPaul said:


> This would be really nice to know.
> 
> But to have it display "DONE" when it really isn't? Kinda defies logic, wouldn't you say? :laughing:


Just like the Duracell/Energizer 15 minutes chargers, even though the LED shows finished, it really isn't!


----------



## Mike abcd

wptski said:


> Mike:
> 
> I just put a scope on one of my C9000 today. I just check on the graph and it just showed DONE and had to terminate by -DeltaV because it's connected outside the charger. It's barely warmed the 1.8Ah cells at 1A rate anyway. It's showing 160ma topoff rate.
> 
> PWM ON portion of the signal is rather noisey too. I have a pair of current probes that don't read exactly the same but close and I'm assuming that the noise/hash is causing one to read over 200ma lower than the other one!



That's really surprising. I wouldn't expect a top off charge after a -dV/dt but only after dT/dt.

I'd also expect .1 C and if I understand you correctly, you charged at 1000 mA and am seeing 160 mA.

If you notice it terminate, I'd be curious how long after the fast charge ended.

Thanks,
Mike


----------



## Mike abcd

I've run a bunch of cycles with 4 cells inserted that were previously charged and allowed to rest for 30+ minutes. I haven't seen any missed terminations at rates from 500-2000 mA on cells that tested 2100-2400 mA.

I also have run a few charge cycles on the same cells at 1000-2000 mA rates when they were fully discharged with no issues.

I'm going to play with older abused cells and partially discharged ones next.

Hey, in hope of a quick answer...can anybody tell me how to open the plastic belt "hoop/ring" on the newer style Fenix holsters. I'm too stupid to figure it out and I've tried pulling/twisting etc. Can't even see a seam...

Mike


----------



## wptski

Mike abcd said:


> That's really surprising. I wouldn't expect a top off charge after a -dV/dt but only after dT/dt.
> 
> I'd also expect .1 C and if I understand you correctly, you charged at 1000 mA and am seeing 160 mA.
> 
> If you notice it terminate, I'd be curious how long after the fast charge ended.
> 
> Thanks,
> Mike


Mike:

It's listed as 100ma topoff not .1C. I just checked again and the topoff is still going pushing 80 minutes now. Yes, I was charging at 1A which was DONE at 90 minutes. Yes, it shows 160ma topoff rate. I wanted to save the results, maybe to post the graph here later. This is cutting into my sleep time now! 

EDIT: That was a big waste of time, I was looking at the error in my probe as it wouldn't go to zero. I'll have to check my probes on some non-PWM current but I think that it's the hash coming from the charger that messing things up. Darn, I hate when you lose sleep over this hobby!


----------



## bcwang

Thinking about this whole top-off charge thing, this probably throws a wrench in how the analyze and cycle mode calculations work. I'm assuming there is no top-off charge in those modes (otherwise it'd be a very long wait), so you won't be getting as complete a charge for the test value. So your regular charge with the top-off should net better results than what you see in the analyze mode. Guess someone could try it one day by doing a regular charge, waiting 2-3 hours, then reset the battery and do the discharge test. That should give a higher reading than doing the regular analyze mode.


----------



## moldyoldy

Hi Mike abcd, 

yup, I made the same mistake with the Fenix holsters. The belt loop is in the _double_ layer of fabric immediately behind the holster. I was slightly embarrassed too!

Tim


----------



## wptski

bcwang said:


> Thinking about this whole top-off charge thing, this probably throws a wrench in how the analyze and cycle mode calculations work. I'm assuming there is no top-off charge in those modes (otherwise it'd be a very long wait), so you won't be getting as complete a charge for the test value. So your regular charge with the top-off should net better results than what you see in the analyze mode. Guess someone could try it one day by doing a regular charge, waiting 2-3 hours, then reset the battery and do the discharge test. That should give a higher reading than doing the regular analyze mode.


bcwang:

I assume that there is no topoff during cycling mode till the last charge and if it is what it says, it's only [email protected] min. R&A mode, it might during the rest period but we won't know till we're told or me/somebody else checks it.

Today I'm going look into my current probe snafu from last night too.


----------



## bcwang

I wonder if I'm the first to have this happen. I have fujicells that don't detect in slot 1 and 2. It seems to have a shorter top contact and can't make contact with the charger because of the recessed design. There must be some manufacturing variation such that slot 3 and 4 on my charger has the contact a bit shallower so these same batteries do make contact.

On another note, for those of you who complained that batteries are hard to remove, I tried something new which I had always done on my c204w. Since I had a battery which could not be removed even when sliding it down first (probably longer than most), I found that removing the battery bottom first works easily. In fact, after that, I found inserting and removing all my batteries from the bottom first works much more easily. Looking at the design of the contacts in both the c204w and the c9000, it may even be by design that they want you to slide it in and out from the bottom contact. I noticed if you do it from the top, you just end up scratching the plastic around the contact and require substantially more effort to get cells in and out, on both of these chargers.


----------



## EngrPaul

When I first saw the charger would have a "lift rod", I became excited because I thought this was a cammed mechanism that would help eject the cells from their position with the throw of a lever. When I found out it was a little prop bar for the charger to sit up at an inclined angle, I was a little sad.


----------



## willchueh

Hello everyone, 

The charger does not display the topoff or maintainence charging current on the LCD (e.g. the screen shows 0mA even if performing them). 

DONE is shown after the program terminates, but before any maintainence and/or topoff charge. So, the charger is still applying small currents after DONE. 

William


----------



## BVH

William, thank you so much for actively participating on this forum and providing us with this level of technical information and support! I look at it as quite a unique service on your part.


----------



## willchueh

BVH said:


> William, thank you so much for actively participating on this forum and providing us with this level of technical information and support! I look at it as quite a unique service on your part.



A pleasure as always. When you buy something from Maha, we'd like to think you are buying a product and service. 

William


----------



## David M

BVH said:


> William, thank you so much for actively participating on this forum and providing us with this level of technical information and support! I look at it as quite a unique service on your part.







Could not agree more!!

The MH-C9000 is a marvel of engineering. Thanks, William

Regards,

David M


----------



## wptski

bcwang said:


> I wonder if I'm the first to have this happen. I have fujicells that don't detect in slot 1 and 2. It seems to have a shorter top contact and can't make contact with the charger because of the recessed design. There must be some manufacturing variation such that slot 3 and 4 on my charger has the contact a bit shallower so these same batteries do make contact.
> 
> On another note, for those of you who complained that batteries are hard to remove, I tried something new which I had always done on my c204w. Since I had a battery which could not be removed even when sliding it down first (probably longer than most), I found that removing the battery bottom first works easily. In fact, after that, I found inserting and removing all my batteries from the bottom first works much more easily. Looking at the design of the contacts in both the c204w and the c9000, it may even be by design that they want you to slide it in and out from the bottom contact. I noticed if you do it from the top, you just end up scratching the plastic around the contact and require substantially more effort to get cells in and out, on both of these chargers.


bcwang:

The instructions show how to insert cells but not how to remove them but if you reverse it, it's just how you suggest. 

Have you popped one out and lost hold of it yet? I hope the LCD screen can take a good hit because it's going to get banged sooner or later!


----------



## BVH

If you're worried about screen damage, get some cheap Ipaq or other screen protector material for it. I did that with my Ipod because they scratch just by looking at it.


----------



## wptski

Finally figured out my current clamp probe problem. I assume the hashy PWM is causing my probes to not read correctly the pulsed current but the waveform doesn't lie. Calculating current by using the pulse width and lenght of one cycle figures to about 80ma on topoff rate. I marked the time a cell showed DONE. By the time I got set up and recoding the signal, I lost 15 minutes. The signal dropped to trickle charge at 1:42:40, so add 15 minutes to that and you got 2 hrs for topoff, not one hour as the specs mention. The trickle pulse was too narrow to measure.

I can post the graph but it isn't much more than a line but I may post the hashy PWM though!


----------



## bcwang

wptski said:


> Finally figured out my current clamp probe problem. I assume the hashy PWM is causing my probes to not read correctly the pulsed current but the waveform doesn't lie. Calculating current by using the pulse width and lenght of one cycle figures to about 80ma on topoff rate. I marked the time a cell showed DONE. By the time I got set up and recoding the signal, I lost 15 minutes. The signal dropped to trickle charge at 1:42:40, so add 15 minutes to that and you got 2 hrs for topoff, not one hour as the specs mention. The trickle pulse was too narrow to measure.
> 
> I can post the graph but it isn't much more than a line but I may post the hashy PWM though!



That's the same topoff time as the c204w. I wonder if the topoff rate is the same. I remember the measurements were hard to average because of the pulsed nature of the charge current.

Did you get a different topoff rate for AAA cells?


----------



## wptski

bcwang said:


> That's the same topoff time as the c204w. I wonder if the topoff rate is the same. I remember the measurements were hard to average because of the pulsed nature of the charge current.
> 
> Did you get a different topoff rate for AAA cells?


bcwang:

I didn't check AAA"s rate but the specs only lists one topoff rate, although you'd think that it would be a bit lower.


----------



## wptski

Here’s a few scope of the C9000 and C808M to compare to. The first is a complete pulse which shows some hash/noise or whatever riding on the ON portion of the pulse. The second is a a few pulses from a C808M. The last is the C9000 with a shorter timebase to show the beginning of the pulse.

That shows a fluctuation of about 1.4A in amplitude. I've seen slightly distorded PWM before in chargers but nothing like this before. I'm clueless if this causes any harm or should be there to begin with but I'd say the better the square wave the better you are! Comments please.


----------



## Curious_character

willchueh said:


> Hello everyone,
> 
> The charger does not display the topoff or maintainence charging current on the LCD (e.g. the screen shows 0mA even if performing them).
> 
> DONE is shown after the program terminates, but before any maintainence and/or topoff charge. So, the charger is still applying small currents after DONE.
> 
> William


For how long is the 100 mA topoff charge applied after the end of the normal charge?
Is the topoff charge applied during the "rest" period between charge and discharge when cycling?

c_c


----------



## wptski

Curious_character said:


> For how long is the 100 mA topoff charge applied after the end of the normal charge?
> Is the topoff charge applied during the "rest" period between charge and discharge when cycling?
> 
> c_c


The instructions state one hour for topoff but I tested it with a scope and it goes for two hours. I did check the R&A mode and there was "no" topoff, so I'm assuming that during "all" other rest periods there'd be no topoff.


----------



## paulr

This looks like a great charger and is definitely on my 2007 shopping list even though I have numerous chargers already including a BC900. One feature I'd like to see in some update would be self-discharge analysis. You put in some batteries and the charger charges them up, then cuts charge rate to zero (i.e. no trickle charge). It then monitors the cell voltage (one measurement per day under load is probably enough) over a period of weeks or months, computing the self-discharge rate and identifying problem cells. I keep having cells develop charge retention problems and it's really annoying to try to identify them with manual measurements, labelling the cells, etc. I could even see buying at least one additional MH-C9000 for this purpose since the multi-week analysis keeps the charger tied up for such a long period.


----------



## wptski

paulr said:


> This looks like a great charger and is definitely on my 2007 shopping list even though I have numerous chargers already including a BC900. One feature I'd like to see in some update would be self-discharge analysis. You put in some batteries and the charger charges them up, then cuts charge rate to zero (i.e. no trickle charge). It then monitors the cell voltage (one measurement per day is probably enough) over a period of weeks or months, computing the self-discharge rate and identifying problem cells. I keep having cells develop charge retention problems and it's really annoying to try to identify them with manual measurements, labelling the cells, etc. I could even see buying at least one additional MH-C9000 for this purpose since the multi-week analysis keeps the charger tied up for such a long period.


Buy a charger and it would have to be expensive, tie it up for weeks to find that your $3.00 cell is losing it's charge? Not me!


----------



## paulr

Huh? I aready have several chargers sitting around doing nothing, just like most of us do. If it can be sitting there analyzing self-discharge instead of sitting doing nothing, that's a big win. It's not like I'm using my charger all the time. And I have dozens of cells that might have this problem. At $3 each, getting 20 of them replaced by the manufacturer pays for a whole $60 charger.


----------



## wptski

paulr said:


> Huh? I aready have several chargers sitting around doing nothing, just like most of us do. If it can be sitting there analyzing self-discharge instead of sitting doing nothing, that's a big win. It's not like I'm using my charger all the time. And I have dozens of cells that might have this problem. At $3 each, getting 20 of them replaced by the manufacturer pays for a whole $60 charger.


A ZTS MBT-1 will tell you that. Works for me.


----------



## willchueh

Curious_character said:


> For how long is the 100 mA topoff charge applied after the end of the normal charge?
> Is the topoff charge applied during the "rest" period between charge and discharge when cycling?
> 
> c_c



1) Topoff charge is applied for 2 hours. 
2) Topoff charge and trickle charge not applied during rest period. 

William


----------



## Mike abcd

willchueh said:


> 1) Topoff charge is applied for 2 hours.
> 2) Topoff charge and trickle charge not applied during rest period.
> 
> William



William,

Does the topoff charge current vary with the charge current selected or is it always 100 mA? If it varies, what is the ratio of topoff/charge?

Is the topoff charge only done after dT/dt termination or also after -dv/dt termination.

Thanks for your support.

Mike


----------



## HashPipeK

Lonely Raven said:


> Oh man! I'm glad I'm not the only one to hear that pulsing. It was driving me nuts!
> 
> For being 35, I still have unusually good high frequency hearing, and I hear this. *Meep* pause *Meep* pause *Meep* when I was charging some cells at 1500ma.



Mine also exhibits a noticable whine, click, whine noise. I just assumed it was normal. Perhaps it is not?


----------



## willchueh

HashPipeK said:


> Mine also exhibits a noticable whine, click, whine noise. I just assumed it was normal. Perhaps it is not?



Yep, it's normal. 

William


----------



## macdude22

My 808M clicks, my understanding is that it's the pulse charging mechanism at work.


----------



## wptski

willchueh:

I'd like to hear your comments about the C9000's PWM signals in Post #113?


----------



## willchueh

wptski said:


> I'd like to hear your comments about the C9000's PWM signals in Post #113?



Hey Bill,

Can you tell me more about your measurement setup? Is it via a shunt resistor, current probe, etc? 

William


----------



## wptski

willchueh said:


> Hey Bill,
> 
> Can you tell me more about your measurement setup? Is it via a shunt resistor, current probe, etc?
> 
> William


William:

I used a Meterman CT238 clamp probe with a Fluke 199B. The cell was externally clamped using a wood working clamp fashioned with copper sheets contacts soldered using #13 wire through one set of PowerPole 30A connectors.

I've used this same setup on the BC-900, C808M, C401FS, etc.

EDIT:

Forgot to add that the connections to the charger is a lenght of 1/4" dia rod or actually two pieces with a insulator midway and two 10A clips through the wiring mentioned above.


----------



## bcwang

wtpski,

Did you experience the same hash/noise on all channels?


----------



## not2bright

Here is a simple support question. My MH-C9000 only has 3 rubber feet. With the unit upside down and the screen closest to me, the upper left foot is missing. I shot Maha a quick message about it.

Does anyone else's charger have this condition?

Otherwise it is seems to be working perfectly.


----------



## EngrPaul

Mine is a quadraped.


----------



## N162E

wptski said:


> William:
> 
> I've used this same setup on the BC-900, C808M, C401FS, etc.


Bill, Do you have this data stored? Can the graphs be replotted for the same time periods and amplitude spreads? Looking at them as they are plotted really amplifies the hash appearance of the C-9000. The C808M shows significant spiking, is this good?


----------



## wptski

bcwang said:


> wtpski,
> 
> Did you experience the same hash/noise on all channels?


bcwang:

I have been only connected to Slot#4 at this time so far.


----------



## wptski

N162E said:


> Bill, Do you have this data stored? Can the graphs be replotted for the same time periods and amplitude spreads? Looking at them as they are plotted really amplifies the hash appearance of the C-9000. The C808M shows significant spiking, is this good?


Fred:

I store all data but saying that I couldn't find any current plots for the C808M so I just did one. Comparing to say a BC-900, it's pretty much square with no distortion "until" more than one cell is charging then a small hump is added to the beginning of the ON pulse! It's still clean though.

Yes, the C808M is spiking and I don't know if this is desirable or not. The scope has a filter settings but it still couldn't remove the hash. You can smooth it out by averaging the signal but that's like reducing the sensitivity!


----------



## bcwang

wptski said:


> bcwang:
> 
> I have been only connected to Slot#4 at this time so far.



You should try charging cells at 1amp, one at a time in each channel and listen for the sound in each channel. See if one of the channels sounds different from slot 4 and test that one to see if you get similar or different results.

When I hear channel 1 of my unit, I'm instantly reminded of your hash/noise graph because it sounds like a very inconsistent harsh wavering noise. But channel 2-4 have a very clean high pitched sound. I don't know if the sound it makes has anything to do with the waveform, but just hearing my channel 1 simply makes me picture the waveform you showed.


----------



## wptski

bcwang said:


> You should try charging cells at 1amp, one at a time in each channel and listen for the sound in each channel. See if one of the channels sounds different from slot 4 and test that one to see if you get similar or different results.
> 
> When I hear channel 1 of my unit, I'm instantly reminded of your hash/noise graph because it sounds like a very inconsistent harsh wavering noise. But channel 2-4 have a very clean high pitched sound. I don't know if the sound it makes has anything to do with the waveform, but just hearing my channel 1 simply makes me picture the waveform you showed.


bcwang:

Interesting, I will look into it.


----------



## not2bright

EngrPaul said:


> Mine is a quadraped.



Thanks. Hopefully they will send me my missing foot.


----------



## bcwang

wptski said:


> bcwang:
> 
> I have been only connected to Slot#4 at this time so far.



You should try charging a single battery in each channel at the default rate and listen closely to the sound it produces. Find one that sounds different from your slot 4 and try testing that slot.

My slot 1 has a harsh wavering buzzy tone that reminds me of your graph when I hear it. Slot 2-4 are a more pure high pitched whine on my unit. I wonder if I put my unit up to test if slot 1 would look like your graph while the other slots are the clean waveforms. This is just speculation of course, but we'll know more as more tests are performed.


----------



## wptski

bcwang said:


> You should try charging a single battery in each channel at the default rate and listen closely to the sound it produces. Find one that sounds different from your slot 4 and try testing that slot.
> 
> My slot 1 has a harsh wavering buzzy tone that reminds me of your graph when I hear it. Slot 2-4 are a more pure high pitched whine on my unit. I wonder if I put my unit up to test if slot 1 would look like your graph while the other slots are the clean waveforms. This is just speculation of course, but we'll know more as more tests are performed.


bcwang:

It's just as easy to move my test rig from slot to slot. Not sure if my ears are as tuned as yours! :laughing:


----------



## wasBlinded

It looks like the "hash" wptski's scope is showing on top of the pulse is a 15 kHz signal. That should be a very high pitched whine. I wonder if that is the operating frequency of the C-9000's DC downconvertor?


----------



## wptski

wasBlinded said:


> It looks like the "hash" wptski's scope is showing on top of the pulse is a 15 kHz signal. That should be a very high pitched whine. I wonder if that is the operating frequency of the C-9000's DC downconvertor?


Hmmm, I thought that the frequency was a lot higher that but I'm just going by "my" memory.


----------



## wptski

I just remembered something! While viewing the hashed pulse above, I saw a periodic lenghtening of the pulse which appears to be 100% duty cycle. The DC-900 does this too. This increased duty cycle is sync'd to the audible buzzing which William Chueh said was coming from the buck switchers. Is this another name for the DC downconverter? Sorry, I'm electronicaly challenged!


----------



## Thujone

FWIW T/D Is sending a new power supply for mine. Great support as usual.


----------



## DogLeg

*Re: Maha MH-C9000 SUPPORT / Question Re: Refresh & Analyze*

I just got my c9000 yesterday evening. I put four new 2100mAh iPowerUS NiMH cells into the charger, set them on R&A for 1000 charge/500 discharge. 

This morning 3 of the cells were done and the numbers looked "reasonable".

The 4th cell was still going, and the charge read 8000+ mAh - plus the cell was rather hot. I disconnected the charger, let the cell rest for an hour and am now discharging it at 1000mA.

Any thoughts why this one cell was "wacky"?


----------



## ARTofAWD

I've been playing with the same iPower 2100 cells as well. One never terminates !! Regardless of a break-in current, 0.6A, 1.0A, or 2.0A charge. I've had to remove the cell everytime just cooking with over 15 A going into it !!


Another cell won't charge at all, in fact the charger won't even see it so I can't select any options for it. Although this battery will charge in a 'dumb' charger.


----------



## wasBlinded

wptski said:


> Hmmm, I thought that the frequency was a lot higher that but I'm just going by "my" memory.


 
Looking at it more carefully, it looks like the time period of the high frequency cycle is 80 microseconds. That would be a 12.5 kHz signal.

Sure, a "buck switcher" sounds like a DC down-convertor to me.


----------



## wptski

wasBlinded said:


> Looking at it more carefully, it looks like the time period of the high frequency cycle is 80 microseconds. That would be a 12.5 kHz signal.
> 
> Sure, a "buck switcher" sounds like a DC down-convertor to me.


So that would mean that the hash isn't from the "buck switcher".


----------



## wptski

bcwang said:


> You should try charging a single battery in each channel at the default rate and listen closely to the sound it produces. Find one that sounds different from your slot 4 and try testing that slot.
> 
> My slot 1 has a harsh wavering buzzy tone that reminds me of your graph when I hear it. Slot 2-4 are a more pure high pitched whine on my unit. I wonder if I put my unit up to test if slot 1 would look like your graph while the other slots are the clean waveforms. This is just speculation of course, but we'll know more as more tests are performed.


I just tested both my chargers slot by slot. The hash just isn't the same from slot to slot. At the beginning where the amplitude is smaller, that varies in some, it was Slot#1 on one and Slot#2 on the other. There a slot or two where the overall magnitude was smaller too. If it varies from slot to slot and charger to charger, I'd say that it isn't supposed to be there!

As far as the audio sound goes, I found out that my scope hums too!


----------



## summerwind

hi guys,
following along in this thread and learning a tremendous amount, have any of you formed an opinion on whether or not the C9000 should be returned to wait for an updated version whereby the bugs should be ironed out?


----------



## wptski

summerwind said:


> hi guys,
> following along in this thread and learning a tremendous amount, have any of you formed an opinion on whether or not the C9000 should be returned to wait for an updated version whereby the bugs should be ironed out?


I wouldn't rush to send it back. If changes come, it'll be some time before they do. I don't know anything about how it's made inside or programable or not but I doubt it. It took almost a year before the BC-900 v33 came out to replace the v32's!!

Nobody knows anything for sure right now.


----------



## summerwind

i think you are right Bill,
i didn't really want this charger for just charging batts.
so far i have run almost all my cells through the break-in to see where they stand, and this really put a lot of doubts in certain cells to rest.
i'll use it for the features that tell me what i need to know and leave the charging up to the c801 i have.
it's just too bad that with the reports of none termination in some cells reported creates doubt in leaving batteries in the charger while being away.

while i really like it for it's analyizng capabilities, it's hard not to feel somewhat cheated at the same time as the only cells i have actually done a charge with were also showing the overheating symptoms in slots 2 and 3 of which i just terminated the charge manually. they were also showing over 4,200 mah's.


----------



## wptski

summerwind said:


> i think you are right Bill,
> i didn't really want this charger for just charging batts.
> so far i have run almost all my cells through the break-in to see where they stand, and this really put a lot of doubts in certain cells to rest.
> i'll use it for the features that tell me what i need to know and leave the charging up to the c801 i have.
> it's just too bad that with the reports of none termination in some cells reported creates doubt in leaving batteries in the charger while being away.


There is a fail safe that could be used, a simple mechanical timer. If cells are fully discharged, you figure the rate for the capacity with a bit extra time and your good to go! A partially discharged cell would be guess work but could be set to stop a really lenghty/missed termination situation. It wouldn't be prone to power failure either although the charger will still RESET!


----------



## powergnome

ARTofAWD said:


> I've been playing with the same iPower 2100 cells as well. One never terminates !! Regardless of a break-in current, 0.6A, 1.0A, or 2.0A charge. I've had to remove the cell everytime just cooking with over 15 A going into it !!
> 
> 
> Another cell won't charge at all, in fact the charger won't even see it so I can't select any options for it. Although this battery will charge in a 'dumb' charger.



Hello,

New to this forum, and have also purchased the MH-C9000 charger along with some Maha 2700 AA and 1000 AAA batteries. Appears to work well except it wont charge a couple of "Kaito" 1300 mAh battery that came with Kaito radios I purchased some time ago. These batteries are generally good quality and charge fine inside the radios themselves, or in other chargers. The problem is that these particular batteries have slightly shorter +/positive caps, and the top of the battery cyclinder body actually "bottoms out" on the MH-C9000's plastic casing in the slot area - and the + cap never makes contact with the MH-C9000's contact, so the charger never sees it, similar to what you are experiencing.

I've written to Thomas Distributing about this and their reply was they were able to charge all batteries that they have, except the AccuPower 2900 mAh AAs - though they did not detail if this was for the same issue, or something else entirely. The recessed slots on the positive terminals is suppose to be a "safety design", but it looks like they may be a tad "too recessed" for some batteries. May be a reason for concern for future battery purchases. The Maha brand and other AA brands I own appear to make good contact on the charger's contacts.

Another concern is with the AAA negative contacts on the charger, I can barely get AAA batteries to "click into" and to hold and stay within their slots. This includes Maha's brand of AAAs. Once in, they seem to charge fine without "popping" out of the slot. But I'm concerned on how these contacts will hold up over time.

If you can confirm this same senario with a battery brands you have, you may want to let T/D and Maha Energy know about it so that can track and correct these problems if needed.


----------



## NiOOH

wptski said:


> There is a fail safe that could be used, a simple mechanical timer. If cells are fully discharged, you figure the rate for the capacity with a bit extra time and your good to go! A partially discharged cell would be guess work but could be set to stop a really lenghty/missed termination situation. It wouldn't be prone to power failure either although the charger will still RESET!


 
Yes it could be done, but to me, the most sophisticated AA/AAA charger analyzer should not need this to operate safely. If something, the timer could have been inside the charger, with user selectable time. Also by using the timer, you'll lose all the information about the charge, plus the top-off and maintenance charge


----------



## FsTop

Would it be difficult to limit the charge at perhaps +50% over the cell capacity set? Seems like an easy fix, if this is really a problem, and not just one or two sub-par chargers...


----------



## SilverFox

Hello FsTop,

The Triton, ICE, and Schulze chargers do something similar. When you set up to charge, you enter the cell capacity (or slightly higher). If the charger puts that value into the cell without terminating, it terminates and gives a maximum quantity message.

This would involve one more step during the set up, but I think it would be a good safety to have.

Tom


----------



## FsTop

During a "Breakin" mode charge, where the low charging rate can cause problems, you already enter the cell capacity. Too bad Maha didn't use it for overcharge prevention...


----------



## AndyTiedye

EngrPaul said:


> Mine is a quadraped.



Mine was briefly tripedal after I attempted to fit it into the carrying case.
It does not fit.
I was able to reattach the missing rubber foot after I found it stuck to the
inside of the case and gave up on trying to fit the charger in there.


----------



## AndyTiedye

ARTofAWD said:


> Another cell won't charge at all, in fact the charger won't even see it so I can't select any options for it. Although this battery will charge in a 'dumb' charger.



I had a new Kodak AAA that the Maha doesn't see. It just pretends the slot is empty when I put that battery in.
My C Crane charger charged it just fine.
I put it in with the other 3 that came in the same package and tried a break-in cycle. The other 3 terminated normally, this one didn't even start.


----------



## jusko

Don't know why the C9000 doesn't have a program that performs "discharge - charge - stop" cycle ? Most chargers do that.


----------



## SilverFox

Hello Jusko,

It doesn't have that cycle because we specifically asked for a discharge only cycle, and Maha listened.

Tom


----------



## jusko

Thanks SilverFox, but what is the purpose of a discharge only cycle ? You have to charge the cells finally.

jusko


----------



## macdude22

Lets your average Joe Blow like me test self discharge of a cell or the ability of another charger to charge a cell with a reasonable accuracy.


----------



## SilverFox

Hello Jusko,

It also is a good way to store cells for the short term (30 days or less).

Tom


----------



## jusko

Thanks "macdude22" and "SilverFox".


----------



## EngrPaul

Stange chirping all of the sudden?!?

I've tested 48 batteries so far. No strange noises.

I just put in 4 new Powerex 1000 AAA cells. One of them took a very long time to be recognized, maybe 30 seconds. I could hear a high-pitched pulsing that I never heard before. Once programmed for break-in, the high pitched sound became quick little chirps, about once per second. If taken out, the charger makes no such sounds with the other 3 cells. Then it still takes a long time to be recognized on restart.

Is there anything I should know about this noise?


----------



## powergnome

powergnome said:


> Hello,
> 
> The problem is that these particular batteries have slightly shorter +/positive caps, and the top of the battery cyclinder body actually "bottoms out" on the MH-C9000's plastic casing in the slot area - and the + cap never makes contact with the MH-C9000's contact, so the charger never sees it, similar to what you are experiencing.
> 
> I've written to Thomas Distributing about this and their reply was they were able to charge all batteries that they have, except the AccuPower 2900 mAh AAs - though they did not detail if this was for the same issue, or something else entirely. The recessed slots on the positive terminals is suppose to be a "safety design", but it looks like they may be a tad "too recessed" for some batteries. May be a reason for concern for future battery purchases. The Maha brand and other AA brands I own appear to make good contact on the charger's contacts.



Another response from TD reqarding Accupower AA 2900 not charging in this charger..... :

The charger is offset and the 2900 Accupower positive battery terminal is just too short.While the Accupower 2900mAH AA battery will charge in other chargers just fine it won't charge in the 9000 charger as it won't make contact with the charging terminals. If you would like to exchange for another brand let us know we will do so at no cost to you. 



Eugene Thomas 

Thomas Distributing 
128 E. Wood Street 
Paris, IL 61944


----------



## moldyoldy

FWIW, I also had the Accupower 1000mah AAA cells that would not make contact in a number of chargers, including the Maha 800S, because the AAA negative terminal of the charger was very short. I took a sharp knife and carefully carved off the plastic wrap back to the edge of the flat bottom (negative terminal). I then "burnished" the plastic wrap at the bottom so that it was smooth and would not easily catch on something. Looks almost like it was intentional. and most importantly, it now functions quite nicely.

Tim


----------



## meeshu

wptski said:


> willchueh:
> 
> I'd like to hear your comments about the C9000's PWM signals in Post #113?



Unless I missed it, *I would like to see comment(s) from Maha regarding this also!
*
I've been following various threads on the MH-C9000, and it appears there may be some "issues" (such as failed charge terminations, and inconsistant charging/discharging performance) regarding this charger.

Until there is some clarification on these issues, I'm holding off purchasing this charger for now.


----------



## FsTop

One item in the C-9000 instructions tht could stand to be updated is the statement that the charging current may exceed available capacity by "20 to 30%". This should be corrected to show "...as much as 40%".

I've run a dozen new Eneloop aaa and aa batteries through mine, and they consistently show charging current as about 40+% greater than the rated capacity or the available capacity, i.e. 2850 mah going into a 1900mah AA Eneloop or 1150 mah into AAA Eneloops.


----------



## wptski

FsTop:

Explain more. What exactly were you doing? Mode, etc.


----------



## EngrPaul

If it hasn't already been said, it would be nice to be able to see the discharge capacity on the display during the final 16 hours of the break-in cycle.


----------



## FsTop

The numbers were from using the Breakin mode on new Eneloops. The capacity reported is consistent if I then Refresh&Analyze with the second charge cycle showing maybe 10 mah higher than the first one.

The Eneloops are also remarkably consistent, with each of four new ones showing figures within 20 mah of each other.


----------



## macdude22

Well my C9000 seems to be acting up today. Slots 1-3 are operating perfectly, as soon as you insert a cell in slot 4 it shuts the unit down. Pull the cell from slot 4 and the charger boots back up with the whole boot up sequence. I've tried using it on a variety of power outlets, with a variety of batteries, a variety of options, and number of cells in slots 1-3. It all comes down to slot 4. Anyone had a problem like this? I'm going to contact Maha support tommrow. Im sad, it was working so well for me.


----------



## summerwind

what happened to Will?


----------



## meeshu

Will is still around. He was last here today at 1:45pm.

Apparently, he still hasn't responded to post #113 (regarding the "hash" or high frequency squiggle on the pulse signal)!?


----------



## macdude22

My C9000 has degraded to rebooting constantly when plugged in. Up until this it was functioning admirably. Not sure what's going on, but I'm sure Maha will fix it up right as rain for me. Here's a link to a quick video I shot of the rebooting magic.

http://homepage.mac.com/macdude22/iMovieTheater42.html


----------



## Codeman

If this has already been mentioned somewhere and I missed it, my apologies. When I wanted to charge some CBP1650 AA cells, I discovered that the MH-C9000 doesn't work with flat top cells. Adding a 0.04" thick magnet to the positive end solved the problem, but...

willchueh - is this safe to do? If it just throws some numbers off, I can live with that, but I don't want to do this if it might cause problems.


----------



## 3rdDerivative

Where is Will?

I work in technical sales for a large IT company. When we have something like the deliver of this new charger with some issues, one tends to keep his mouth shut. At least until the the labs folks can check it out. Making guesses on the issues just usually sets false customer expectations and goes no where.

And added to the burden is proprietary info and legal issues. However, I doubt one would sue over a $60 charger and especially if one can return it. LOL.


----------



## jusko

If the C9000 cuts off charging due to high cell temperature, then why doesn't it recharge again after the cells cool down like the BC900 or Sanyo MR57 ?


----------



## summerwind

very well stated, and i can understand this much better.
only thing that concerns me is whether or not i can trust this charger for charging chores when i'm away from home.
so far i like it, but have had a couple termination issues as well.
remember once when i use to fly RC planes, and a charger that had a hi/lo switch for charging the Nicad battery fllight pack. naturally the charging was suppose to be monitored, but i fell asleep only to have my wife wake me up saying that there is a funny noise coming from the end table......DOH, what a mess.
this charger should have been tested rigorously, and i mentioned this in the original thread, and was shot down by a few participants at the time saying that this was not needed................what about now?




3rdDerivative said:


> Where is Will?
> 
> I work in technical sales for a large IT company. When we have something like the deliver of this new charger with some issues, one tends to keep his mouth shut. At least until the the labs folks can check it out. Making guesses on the issues just usually sets false customer expectations and goes no where.
> 
> And added to the burden is proprietary info and legal issues. However, I doubt one would sue over a $60 charger and especially if one can return it. LOL.


----------



## wptski

jusko said:


> If the C9000 cuts off charging due to high cell temperature, then why doesn't it recharge again after the cells cool down like the BC900 or Sanyo MR57 ?


Nobody has yet to see the C9000 stop for high temperature, so nobody really knows what it'll do.


----------



## willchueh

Codeman said:


> Adding a 0.04" thick magnet to the positive end solved the problem, but...


 
Codeman, when adding something in series to the battery, make sure it has very low or practically zero resistance. I wouldn't put anything that will add more than 0.1 ohm to the battery. 

If you get a "HIGH" (high impedance) error, that means the resistance is too high. 

William


----------



## willchueh

jusko said:


> If the C9000 cuts off charging due to high cell temperature, then why doesn't it recharge again after the cells cool down like the BC900 or Sanyo MR57 ?


 
The MH-C9000 treats over-temperature as a "termination criteria" so no recharging is applied after the temperature drops. In my opinion, it might be a little dangerous to restart a charge after temperature drops as the over temperature may signify that something is wrong with the cell. 

In addition, when a charge is restarted, it will take time for negative delta V to appear, typically 5-8 minutes. 

William


----------



## Codeman

willchueh said:


> Codeman, when adding something in series to the battery, make sure it has very low or practically zero resistance. I wouldn't put anything that will add more than 0.1 ohm to the battery.
> 
> If you get a "HIGH" (high impedance) error, that means the resistance is too high.
> 
> William



Thanks William! I'll be sure to check before I use them again.


----------



## jusko

Thanks William for answering my query in post #179.

Another question I hope William can answer me is that on using a fan. William and FAQ suggested that to achieve better charge completeness at higher currents, a small fan can be added to cool the batteries externally. I have done this many times and confirmed that there is termination difficulty. 

I used an 8cm 12V computer fan which blew right over the 4 charging batteries. The batteries and charger felt cool all the way. But the batteries didn't terminate even after more than 2C had been charged. Then I took the fan away, a few minutes later, all the batteries began DONE.

So, use a fan or not ? Could William explain this please ?


----------



## EngrPaul

Suggestion: How about a Discharge & Charge program? Or is this a bad idea?


----------



## jusko

EngrPaul said:


> Suggestion: How about a Discharge & Charge program? Or is this a bad idea?


 
I support a " Discharge-->Charge " program. Thats a good idea Many other charges do have this program.


----------



## jusko

EngrPaul said:


> Suggestion: How about a Discharge & Charge program? Or is this a bad idea?


 
I support a " Discharge-->Charge " program. Thats a good idea Many other charges do have this program.


----------



## TorchBoy

macdude22 said:


> My C9000 has degraded to rebooting constantly when plugged in. Up until this it was functioning admirably. Not sure what's going on, but I'm sure Maha will fix it up right as rain for me. Here's a link to a quick video I shot of the rebooting magic.
> 
> http://homepage.mac.com/macdude22/iMovieTheater42.html


Sadly, you're not the only one, and I beat you by over a week. My replacement arrived from Maha yesterday morning (Monday 15 Jan), first reported to them Saturday 6 Jan (Friday 5 USA time).

Like yours, mine continually went through its startup sequence, with slot 2 indicated. I found that if I put a cell in slot 2 the other slots worked OK. I'm really not sure what slot 2 was doing at the time - its figures seemed quite off.

I also tried to measure the power supply voltage with a multimeter connected to it with a short extra lead, to see if the supply voltage was dropping, causing the restart. Very surprisingly it fixed the endless restarting... but the charger started *charging* the empty slot 2 ! :huh2: 

Kudos to Maha for getting a replacement to me so quickly but I'm a little worried now. Will the new one die as well? Is it because we're Mac owners?


----------



## macdude22

Glad to see I'm not the only unlucky soul with a rebooting monster. Unless it happens again I'm not going to chalk it up to bad build quality. Maha has already shipped a new unit to me. In electronics these things happen, and I'm surprised it doesn't happen more often. The worst experience with a bad gadget I had was standing in line for 11 hours in 0 degree weather for a Wii getting home and finding out my power supply was bad and a gear fell out of the unit. I had to get everything replaced! I think my local discount store may have been taking less than savory care of those boxes. Nintendo 2 day'd me a new Wii though so that was nice.


----------



## LD500

This forum is filled with battery experts, I'm just a recharge newbie.
I bought a C9000 because I wanted a charger that would maximize the capacity of the batteries for my camera flash, and a few other uses. Almost all AA.

I have a couple newbie questions, hope you can help me out:

1. Will the default charge/discharge rates work well enough for me?
80% of my use will be with 2500ma Sanyo NiMH AA, the other 20%
will likely be with the Sanyo Eneloop 2000 ma AA.
I'm also hoping my wife can use it just by using the defaults.

2. Do I need to worry much about the termination problems I read about?
Just how will I know that something has gone wrong?

3. If you miss the few seconds the charger allows you to set the MODE, is the only way to go back to unplug the unit, wait a few seconds, then plug it back in? Is there any button sequence to go back?

Thanks


----------



## wptski

LD500 said:


> This forum is filled with battery experts, I'm just a recharge newbie.
> I bought a C9000 because I wanted a charger that would maximize the capacity of the batteries for my camera flash, and a few other uses. Almost all AA.
> 
> I have a couple newbie questions, hope you can help me out:
> 
> 1. Will the default charge/discharge rates work well enough for me?
> 80% of my use will be with 2500ma Sanyo NiMH AA, the other 20%
> will likely be with the Sanyo Eneloop 2000 ma AA.
> I'm also hoping my wife can use it just by using the defaults.
> 
> 2. Do I need to worry much about the termination problems I read about?
> Just how will I know that something has gone wrong?
> 
> 3. If you miss the few seconds the charger allows you to set the MODE, is the only way to go back to unplug the unit, wait a few seconds, then plug it back in? Is there any button sequence to go back?
> 
> Thanks


Just use .5C or 50% of capacity. For your 2500mAh cells use 1300ma and 2100mAh cells use 1100ma. Right, there is no RESET button pressses that we know of, so pulling the plug is the only option.

If it misses termination your input mAh will be way over the rating of the cell. I had one go six times over but the cell never overheated!


----------



## wptski

LD500 said:


> This forum is filled with battery experts, I'm just a recharge newbie.
> I bought a C9000 because I wanted a charger that would maximize the capacity of the batteries for my camera flash, and a few other uses. Almost all AA.
> 
> I have a couple newbie questions, hope you can help me out:
> 
> 1. Will the default charge/discharge rates work well enough for me?
> 80% of my use will be with 2500ma Sanyo NiMH AA, the other 20%
> will likely be with the Sanyo Eneloop 2000 ma AA.
> I'm also hoping my wife can use it just by using the defaults.
> 
> 2. Do I need to worry much about the termination problems I read about?
> Just how will I know that something has gone wrong?
> 
> 3. If you miss the few seconds the charger allows you to set the MODE, is the only way to go back to unplug the unit, wait a few seconds, then plug it back in? Is there any button sequence to go back?
> 
> Thanks


Just use .5C or 50% of capacity. For your 2500mAh cells use 1300ma and 2100mAh cells use 1100ma. Right, there is no RESET button pressses that we know of, so pulling the plug is the only option.

If it misses termination your input mAh will be way over the rating of the cell. I had one go six times over but the cell never overheated!


----------



## TorchBoy

wptski said:


> Just use .5C or 50% of capacity. For your 2500mAh cells use 1300ma and 2100mAh cells use 1100ma.


Shouldn't the default 1 amp charge rate be OK too? At 0.4C it's over the minimum recommended 0.33C.



wptski said:


> Right, there is no RESET button pressses that we know of, so pulling the plug is the only option.


I thought pulling whichever cell out for more than 2 seconds worked also?


----------



## wptski

TorchBoy said:


> Shouldn't the default 1 amp charge rate be OK too? At 0.4C it's over the minimum recommended 0.33C.
> 
> 
> I thought pulling whichever cell out for more than 2 seconds worked also?


MAHA's William Chueh suggested that the manual's .33C should be changed to .5C, so I'd always go on the high side to insure proper termination. I just charged two Energizer 2.5Ah cells at 1A but was watching them and had no problem. Use your own judgement.


----------



## SilverFox

Hello Ian,

I agree with Bill, however I have not had any problems using the default charging rate.

Tom


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## SilverFox

Hmm Double...


----------



## TorchBoy

wptski said:


> MAHA's William Chueh suggested that the manual's .33C should be changed to .5C, ...


I can remember seeing this (or the reverse???) but the last time I went looking for it I couldn't see where he had said it. Was it in this thread or the first (big) C9000 thread?


----------



## LD500

wptski said:


> MAHA's William Chueh suggested that the manual's .33C should be changed to .5C, so I'd always go on the high side to insure proper termination.


 
If I recall correctly, the manual on my C9000 recommends 0.5C to 1.0C
I just received my unit yesterday so maybe they adjusted the manual.
All this talk of improper termination has me worried though.
Hopefully sticking with at least 0.5C will allow the unit to sense termination properly.

Silly question, I do only have to set one charging rate and discharge rate for all 4 slots right? I know I have to set the mode 4 times separate for each slot.


----------



## wptski

I don't remember what thread it was mention by William Chueh in.

Look at "Choosing the right charging & discharging rate" under the main heading of "General Battery Education".


----------



## TorchBoy

Both my manuals and the PDF from their web site say 0.33C. When William mentioned it I thought he refered to the PDF as being the latest version. Maybe I'm thinking of another post. I think this was the 0.5C post:

https://www.candlepowerforums.com/posts/1760477&postcount=49

LD500: Each slot is set separately for currents as well. It's a feature.


----------



## jusko

jusko said:


> Thanks William for answering my query in post #179.
> 
> Another question I hope William can answer me is that on using a fan. William and FAQ suggested that to achieve better charge completeness at higher currents, a small fan can be added to cool the batteries externally. I have done this many times and confirmed that there is termination difficulty.
> 
> I used an 8cm 12V computer fan which blew right over the 4 charging batteries. The batteries and charger felt cool all the way. But the batteries didn't terminate even after more than 2C had been charged. Then I took the fan away, a few minutes later, all the batteries began DONE.
> 
> So, use a fan or not ? Could William explain this please ?


 

Hi, William, do you have any ideas please ?


----------



## TorchBoy

My idea is that a fan only cools the outside, which is also where the charger measures, possibly leading to inaccurate readings, but it's the heat inside that does the damage. But it's just an idea - I have no idea what the thermal conductivity of a NiMH cell is. William? Tom? Bill?


----------



## wptski

Funny, I got a few books on IR imaging and one thing I was just reading is that all metals, liquids,etc. react differently, meaning the amount of heat it takes to raise the temperature 1F. These cells are made up of different metals, etc. The mass is a variable too, so these higher capacity cells with thinner, smaller components react differently than older cells. Heat travels from warmer objects to cooler objects too! If this doesn't make you think, nothing will. 

EDIT: Cells connected externally to the C9000 run much cooler and still terminate. You'd think that, as long as the fan was used from the start of the charge, it wouldn't affect the operation aside from keeping the cells cooler. On the other hand, is it possible to keep them too cool? Do you need a bit of heat for the chemical process to take place correctly, more so on higher capacity cells, maybe????


----------



## verge

According to the MH-C9000 user manual;

"Charging at a rate below 0.33C and above 1.0C is not recommended."

I don't understand why the BREAK-IN charge rate of MH-C9000 is 0.1C while the recommended CHARGE rate for NiMH battery is minimum of 0.33C. 

How can the BREAK-IN mode properly charge a NiMH battery if the recommended minimum charge rate is 0.33C?


----------



## coppertrail

This mode charges @ .1C for a fixed time, and thus does not over charge. It is designed to form the cell by evenly distributing the electrolytes. The concern with charging below .1C on a non-timed charger is that it will miss the cutoff and potentiall overcharge the cell(s).


----------



## verge

coppertrail, thanks much for the quick reply and explanation. 

Another quick question, is the one hour battery rest period absolutely necessary or it can be cut down to lesser time period (15 - 30 mins) for faster break-in process?


----------



## coppertrail

It cannot be changed on the MH-C9000, and the one hour rest period is recommended for the break in cycle. I know, it takes a long time  . . .

Also, it appears the Eneloops need not be broken it.


----------



## SilverFox

Hello Verge,

Welcome to CPF.

If you are in a hurry, pull the cells after the 16 hour charge and use them.

Tom


----------



## bmoorhouse

I have been testing out my C9000 since I received it the other day. I wanted to see if there was a difference between 0.33 and 0.5 C with new cells and if the charger would terminate relatively new cells at 0.33 C. One of my concerns with the charger is that 0.5C may be too fast and not gentle enough to use for regular every day charging. 

I discharged four 2000 mah batteries I bought one month ago using the discharge cycle over night. The next morning, I put them back in and set the first to charge at 400 ma, the next 700 ma, the third at 1000 ma, and the last at 2000 ma.

I expected the first one to miss termination, which it did, and I manually stopped it at 3250 mah after 544 minutes. Despite being well over, the cell was not hot to the touch. Of course, I was charging in my cold garage, so that might have kept the outside temp down.

The other three did well. The slowest one, charged at 700 ma or about 0.29 C actually terminated. It did go a little long, terminating at 2452 mah while the others stopped at 2379 and 2393 mah, but it was not hot. Was the fact that it went long due to the fact that it was charged slowly? I thought that if I charged too slowly it would miss the one and only signal and continue charging indefinitely. Since the additional 425 mah applied is well within the 30% MAHA says each charge capacity could go over the rated capacity by, I wasn't sure. 

I then discharge all four and the C9000 indicated 2209, 2108, 2104, and 2074 mah. The one with 2209 was, of course, the one I charged at 400 mah and manually terminated.

When I was finished I went ahead and used a default charge cycle to recharge all four. Their capacities this time were 2375, 2321, 2399, and 2459 mah. The 2459 mah capacity was shown on the one that I had earlier charged at 2000 ma, but seeing it from a default charge made me feel better about the 2452 mah I saw when charging at 700 ma.

After all of this, I have a few questions . . . I understand the charging capacity can exceed the actual capacity by as much as 30%. If that's the case, what benefit (other than observing a failed terminiation) is there from seeing the charging capacity? Can you use that amount to verify matched sets?

My last question has to do with the C9000's effect on the batteries' overall life. The C9000 slightly overcharges the cells, while some others slightly undercharge. The slight overcharge ensures that each charge will enable the longest use before the next required charge, but this comes at the expense of potentially reducing the nubmer of charge cycles the battery can accept. If I wanted to get the maximum number of camera flashes throughout a battery's life, would I be better off using a charger that requires more frequent charging with more cycles or this one that gives me more flashes per charge, but with which I may get fewer cycles?


----------



## bmoorhouse

Can someone answer a few questions for me:

I understand the displayed charging capacity can exceed the actual capacity by as much as 30%. If that's the case, what benefit (other than observing a failed terminiation) is there from seeing the charging capacity? Can you use that amount to verify matched sets?

The C9000 slightly overcharges cells to ensure they are fully charged. This slight overcharge can potentially damage the cells and reduce the nubmer of charge cycles the battery can accept. If I wanted to get the maximum number of camera flashes from a set of batteries before throwing them out, would I be better off using a charger that undercharges and therefore requires more frequent charging or the C9000 that gives me more flashes per charge, but with which I may get fewer cycles?


----------



## verge

Noticing the way above battery's rated capacity shown on the MH-C9000 display after the CHARGE process when I BREAK-IN my first set of AA batteries (Kodak 1600 NiMH AA), I decided to do another round on a different set of batteries and write down the numbers. 

After the BREAK-IN of the first set of batteries, I started BREAK-IN of another set (Kodak 1700 NiMH AA) and reminded myself to write down the numbers shown on the display at the end of CHARGE. The batteries were inserted into the charger's four slots (6:15am 1-22-07) and CHARGE finished at 10:15pm (1-22-07). 

Here is the information I gathered from the charger's display right after the CHARGE process and before the REST period;

Batt.1	2427 MAH	1.45 VOLT	960 MIN
Batt.2	2434 MAH	1.45 VOLT	960 MIN
Batt.3	2443 MAH	1.45 VOLT	960 MIN
Batt.4	2436 MAH	1.46 VOLT	960 MIN

My very obvious question is why is charging capacity shown on the display 43% over the rated capacity of the batteries? What does this mean?


----------



## DynoMoHum

Good questions about what a person might get from looking the total amount of current sent to the battery during a charge period... I don't know the real answer... However you must also realize that this number could be very misleading, unless you know for sure how much if any charge was in the battery(s) before you started charging. I think the general question of what if anything can be learned from the total charging current is more of a generic question about batteries then it is about this particular charger.

I personally have never head anyone explain the answer to your question... So I too am somewhat curious as to what the answer is. However, I really don't expect there to be any really useful information to be learned from that number.


----------



## willchueh

BREAK-IN mode, by definition, charges ~160% (16 hours at 0.1C) of the entered battery capacity. This is to allow for battery forming.

Regards,

William


----------



## Mike abcd

It's interesting Maha stuck with the 16 hours even though the actual charge rate turns out to be slightly under .1 C.

It looks like it actually delivers about 143% vs 160% for a standard 16 hour .1 C charge.

Only an observation, not a complaint as I'm not a believer in doing the "standard" forming charge on new cells. I find a few fast charge cycles to be just as effective and quicker while avoiding the large over charge of a "standard" forming charge.

Mike


----------



## SilverFox

Hello Bmoorhouse,

The capacity going into a cell has no value, other than as a gross indication of where you are in the charging process. If you are charging a 2000 mAh cell, and the capacity going into the cell is showing 1500 mAh, you are not quite done charging yet. On the other hand, if it reads 3000 mAh it probably means that your charger had missed the termination.

There has been some effort to try to find a correlation between the amount of charge input to battery performance, but that correlation is not readily apparent.

The RC chargers often use maximum capacity as a safety cut off. If you are charging 3300 mAh Sub C cells, you would select 5000 mAh as a maximum charge put in. When your charger misses the end of charge signal, it will finally terminate on the maximum quantity you selected.

There are several consumer chargers that also utilize this for charge termination, but it is a fixed number and not user adjustable. I have mentioned this to William, but do not know if it can be implemented into the C9000. People who are charging high capacity cells on their BC-900 chargers at low charge rates, are probably terminating on the 3000 mAh capacity built into the charger, rather than the charger actually seeing an end of charge signal.

Your last question is difficult to comment on. We need some common definitions, but they are illusive.

Let’s gain some perspective and embrace the fact that cells die. They die while in storage and they die while in use. If you use your cells, they are being damaged every time you charge or discharge them. The idea is to minimize the damage.

We look to the battery manufacturers to give us an idea of life expectancy. The battery manufacturers look for standard procedures to test to. Now we have a basis to start from.

The standard charge is a 16 hour, constant current charge at a rate of 0.1 C. The standard discharge for capacity involves a 0.2 C constant current discharge rate and a cut off voltage of 1.0 volt per cell. The standard for determining cycle life involves measuring the number of standard charge/standard discharge cycles it takes before the capacity drops below 80% of its initial standard capacity.

If you want to realize the advertised cycle life from your cells, follow the standard charge and standard discharge guidelines.

There is no standard for fast charging.

The battery manufactures realized that there are some things that happen during fast charging. The cell temperature can increase, the voltage can stabilize or drop, and the internal can pressure increases. The charger manufacturers approached their chip suppliers to provide them with a controller that would enable them to charge at faster rates.

As cell chemistry changed from NiCd to NiMh, it was observed that the voltage related end of charge signal was enhanced at faster charge rates. Now we have a recommended charge rate of 0.5 C to 1.0 C, with most of the charging data being given for 1.0 C charge rates.

Two problems arise. We find ourselves in a situation where we using the cells differently from how they are rated according to the standards and while we have an idea of what is going on at a 1 C charge rate, we have little information on what an overcharge is at lower charge rates, and what the effects of such an overcharge is.

That last statement is not entirely true. The Swedish did a study comparing a 30% overcharge at 1 C. Their study revealed that cycle life dropped from roughly 500 cycles to roughly 100 cycles when the cell was charged at a 1 C rate to a 30% overcharge. 

They went on to find that at a lower charge rate of 0.3 C, a 30% overcharge dropped the cycle life down to roughly 225 cycles. 

We could probably conclude that charging at higher rates results in higher cell temperatures, and the higher temperatures caused the reduction in cycle life. However, no temperature data was taken during the testing.

Unfortunately, they did not continue the test to show the effects of a 10% or 20% overcharge. We can speculate that it should be less than a 30% overcharge, but that is about it. Their testing was done with 1800 mAh Duracell cells.

We need a definition of a full charge at a fast charge rate to answer your question. 

One definition could be that a full charge occurs when the cell temperature raises 20 F above ambient when charging at 68 F. Another could be that a full charge occurs when the rate of temperature rise is 1.8 F per minute over a window of a few minutes. Another is to check for a drop in voltage during the charge. With this metric, the sensitivity needs to be determined. You will get different results using a 3 mV drop than when using a 10 mV drop. Another would be to first discharge the cell, then time the charge going back in, of course the right amount of time varies with the charge rate.

One interesting thought is to assume that the charge and discharge characteristics are similar, do a standard charge followed by a discharge at the rate we want to charge at. Now we have a capacity for that rate and can factor in the charger efficiencies and come to what would be necessary for a full charge.

How do you get the most from your cells? Use your cells until you notice increased recycle times in your flash. Charge them at a 0.1 C rate for 10 hours, then pull them off the charger. Do not expect the charger to terminate the charge. Set a timer and pull them after the time is up. Every 20 cycles, use the Break In function. 

You will have to anticipate your needs with this method and may need to have a few extra sets of cells around for the times when you are waiting for a charge to complete. You will have to balance storage times with use times. I don’t believe in leaving cells on the charger, but you may be able to get away with it with normal cells. If you use a low self discharge cell, don’t leave it on the charger for any extended length of time.

Let me know how it works out…

Tom


----------



## verge

Kodak 1700 NiMH AA (1-yr old unused batteries)
MH-C9000 / BREAK-IN (start 1-22-07 6:15am; end 10:00pm 1-23-07)
CHARGE 1
Batt.1	2427 MAH	1.45 VOLT	960 MIN
Batt.2	2434 MAH	1.45 VOLT	960 MIN
Batt.3	2443 MAH	1.45 VOLT	960 MIN
Batt.4	2436 MAH	1.46 VOLT	960 MIN

REST	60 MIN

DISCHARGE (last reading at the end of DISHARGE process)
Batt.1	1744 MAH	1.14 VOLT	60 MIN
Batt.2	1746 MAH	1.14 VOLT	60 MIN
Batt.3	1778 MAH	1.14 VOLT	60 MIN
Batt.4	1776 MAH	1.14 VOLT	60 MIN

REST	60 MIN

CHARGE 2 (last reading at the end of CHARGE process)
Batt.1	2428 MAH	169 MA	1.46 VOLT	960 MIN
Batt.2	2432 MAH	167 MA	1.46 VOLT	960 MIN
Batt.3	2438 MAH	169 MA	1.46 VOLT	960 MIN
Batt.4	2431 MAH	168 MA	1.47 VOLT	960 MIN

AVAILABLE CAPACITY shown on display after each battery got DONE.
Batt.1 1730 MAH	338 MIN	1.44 VOLT
Batt.2 1746 MAH	343 MIN	1.44 VOLT
Batt.3 1734 MAH	338 MIN	1.44 VOLT
Batt.4 1776 MAH	349 MIN	1.45 VOLT

Next question is wazzup with the lesser time displayed (e.g. 338 MIN) for each battery when DONE? What does it mean?

I'm setting up a different set of batteries for BREAK-IN. I just have to start Friday morning so I can catch the end of first CHARGE (to copy the information on the display) when I get home from work. The DISCHARGE on late Friday night and last CHARGE would be on Saturday and I'm conveniently at home to write down what's on the MH-C9000 display at the end of last two stages of BREAK-IN.

* (edit) I changed my mind. I now have a set of 4 old JWIN AAA batteries on BREAK-IN in my MH-C9000. This charger has been continually at work since I started feeding it with batteries.


----------



## SilverFox

Hello Verge,

The standard IEC charge is 16 hours at a 0.1 C rate. The standard discharge for capacity is at 0.2 C. This usually results in a 5 hour discharge (300 minutes), however it looks like your cells had more than their rated capacity. This means that it took over 5 hours to complete the discharge.

Tom


----------



## verge

Thanks for the response SilverFox! This charger has numbers (e.g. 338 MIN when DONE in BREAK-IN) that show on the DISPLAY that are not fully explained on the manual.

Also, it's such a pain to wait 39 hours to know that my batteries are ok and up to their rated capacity.

I wish there's a battery tester that immediately shows battery's capacity in mAh numbers instead of yellow led light or meter needle that just swings to GOOD or RECHARGE/REPLACE.


----------



## TorchBoy

SilverFox said:


> Let’s gain some perspective and embrace the fact that cells die. They die while in storage and they die while in use. If you use your cells, they are being damaged every time you charge or discharge them. The idea is to minimize the damage.


Words of wisdom. I've finally finished playing, er, testing my new Eneloops on my MH-C9000 and moved on to a dozen AAA cells I've had for a while. Over half of them came up as HIGH impedance on the charger, and I still haven't been able to get four of them working. Maybe I shouldn't have given my old less-intelligent charger away so soon? Is there anything I can do to reduce their impedance?


----------



## bmoorhouse

Wow, Tom. Thanks for the very in depth answer to my question. It definitely helped me to understand the effect of using different charge rates.



SilverFox said:


> Let’s gain some perspective and embrace the fact that cells die. They die while in storage and they die while in use. If you use your cells, they are being damaged every time you charge or discharge them. The idea is to minimize the damage.



I never said I expected my batteries to last forever. I know they will die. But if the study you referenced has repeatable results, than using fast charging rates are extremely detrimental to the longevity of batteries. 

It would be one thing if fast charging cost a small percentage of cycles, but based on the results of the Swedish study, a 0.5C charge on the C9000 could cost you over half the life expectancy of the cell with the 1.0C charge costing close to 80% of the batterie's overall life. That's crazy! Batteries aren't exactly expensive, but they aren't entirely cheap either, and I don't like the idea of having to replace them twice as often as I might otherwise have to.

You adviced me earlier to stay away from the C-9000, that it had some problems - I wish I had listened. Though I would be without the analyzer functions (which I really like), other chargers such as the 800S would have been a very dependable charger and with the 500 mah slow charge rate, my 2000 mah cells would last me a lot longer.

As for setting a timer or manually stopping the charger, I thought that was what I was buying a smart charger to do for me.


----------



## TorchBoy

bmoorhouse said:


> You adviced me earlier to stay away from the C-9000, that it had some problems - I wish I had listened. Though I would be without the analyzer functions (which I really like), other chargers such as the 800S would have been a very dependable charger and with the 500 mah slow charge rate, my 2000 mah cells would last me a lot longer.


Doesn't the MH-C9000 charge at 500mA (sic) if you tell it to? Or are you making a reference to possible termination issues with the C9000? Apart from that it seems great, and like you I really like the analysis functions. That's a great reason in itself to get it.


----------



## SilverFox

Hello Ian,

When you run into cells that give you a "High" reading, try doing a discharge on them first. I sent William some cells that were giving me problems with a "High" reading for evaluation. His initial comment was to do a discharge first. The discharge went fine, as did the following charge, but when I went to recharge the charged cells, I got the "High" reading again.

Tom


----------



## SilverFox

Hello Bmoorhouse,

I don't think you understood what I wrote...

The reduction in cycle life was caused by the 30% overcharge, not by the charge rate. 

There is more damage done during an overcharge at a higher charge rate, than during an overcharge at a lower charge rate.

If you review the "Cycle Testing Observations" thread you will find that there is a difference between fast and slower charging, but it only amounts to around 25 cycles. In this case, fast charging was done on the Energizer 15 minute charger, and slow charging was done at 1 amp.

Since you don't want to set a timer, and since the C9000 allows you some ability to program it, here is a work around. You can use the break in mode all of the time, but for normal charging just enter in a lower value for the cell capacity. 

If you have a 2500 mAh cell, select the break in mode and tell the C9000 that it is a 1600 mAh cell. It will take 16 hours to charge this way, but the C9000 will end the charge without you having to set a timer.

Oops, that won't work either. The break in mode on the C9000 does a charge/discharge/charge cycle. You would be running an extra cycle every time you charge. Sorry, you still need a timer to end the cycle during the rest period after the 16 hour charge.

Your question was how to get the most cycle life from your cells using the C9000. I assumed that you were willing to "participate" in the process by setting a timer. If you don't want to take an active role in the charging process, my advice is to only use the default settings.

Let me revise my suggestion...

Start with a Break In cycle. Operate your flash until you notice increased cycle times. Place the cells in the charger and make no selections at all. Every 20 cycles, do a Break In cycle.

If you happen to find a cell that is not behaving properly and has missed the end of charge termination, replace the cell.

Tom


----------



## bmoorhouse

TorchBoy said:


> Doesn't the MH-C9000 charge at 500mA (sic) if you tell it to? Or are you making a reference to possible termination issues with the C9000? Apart from that it seems great, and like you I really like the analysis functions. That's a great reason in itself to get it.


 
The C9000 will charge at 500mA, but will fail to terminate at that current. For what ever reason, however, the 800S will terminiate properly. So, yes, I was making a reference to a confirmed termination issue with the C9000.



Silverfox said:


> The reduction in cycle life was caused by the 30% overcharge, not by the charge rate.
> 
> There is more damage done during an overcharge at a higher charge rate, than during an overcharge at a lower charge rate.


 
It is the second part of this that concerned me. An overcharge of 30% at 1C dropped the available cycles by about 80%. The same 30% overcharged dropped the available cycles by only about 55% at 0.3C. I guess the data I am missing is the effect of an overcharge of 30% done at 0.1C. Perhaps that would yield similar results to the study down at 0.3C. If so, than the longevity reduction at the rates lower than 1.0C could all be attributed to the overcharge. With the numbers I had, I assumed that the reduction at 0.3C was caused by both charging faster than 0.1C and overcharging. I understand what you are saying and realize my assumption could easily be wrong, and probably is.



Silverfox said:


> I assumed that you were willing to "participate" in the process by setting a timer. If you don't want to take an active role in the charging process, my advice is to only use the default settings.


 
I am willing to take an active role as far as setting rates, etc, but I bought a smart charge to avoid having to deal with timers, which can yeild both over and undercharges. Your recommendations, however, are very sound and I appreciat the time and effort in writing them up. If I keep this charger I will certainly follow them. 

My original intention was actually to use the break-in mode for new batteries, the default settings for most charges, the break-in every couple of months for maintenance, and the anaylize if I notice any problems. While I am attracted to the special modes of this charger, clearly the regular charging function are the most important to me. For that reason, I may replace this device with something else like the 800S.


----------



## SilverFox

Hello Bmoorhouse,

You are still missing part of the picture...

The cycle life of a cell is determined by the number of standard charge cycles and 5 hour discharge cycles it takes until the capacity drops to 80% of the original capacity.

Cycle life is defined using a 16 hour 0.1 C charge.

Tom


----------



## TorchBoy

SilverFox said:


> Hello Ian,
> 
> When you run into cells that give you a "High" reading, try doing a discharge on them first. I sent William some cells that were giving me problems with a "High" reading for evaluation. His initial comment was to do a discharge first. The discharge went fine, as did the following charge, but when I went to recharge the charged cells, I got the "High" reading again.
> 
> Tom


I managed to get 4 or 5 of the dozen working by doing that, but the last 4 still won't cooperate, and still read HIGH. Perhaps if I run them through a few cycles of charging in a dumb charger and discharging in the C9000?

(FYI the first two that I got through a break in attained 615 and 616 mAh, for nominal 800 mAh cells. At 76.9% are they out the end of their cycle life already, or is the C9000 just being a bit fussy? They've been fast charged (2-3 hour), and I would have said only 100-150 cycles, if that. I can probably dig up the charging current but I've given that charger and its instruction manual away.)


----------



## B612

TorchBoy said:


> Words of wisdom. I've finally finished playing, er, testing my new Eneloops on my MH-C9000 and moved on to a dozen AAA cells I've had for a while. Over half of them came up as HIGH impedance on the charger, and I still haven't been able to get four of them working. Maybe I shouldn't have given my old less-intelligent charger away so soon? Is there anything I can do to reduce their impedance?


I've been playing with some GP 600mAh AAA's from cordless phones that are a few years old, three of them test high from a full discharge and after a few weeks of playing nothing has changed in them except for the capacity up from around 384 to 513 mAh. If you want to form charge them just put in a good one wait a few seconds until the test has finished then change cells really quickly.


----------



## TorchBoy

B612 said:


> If you want to form charge them just put in a good one wait a few seconds until the test has finished then change cells really quickly.


:laughing: I thought of that. I guess I'll have to try it now. Methinks this charger is never going to get a rest. Thanks.


----------



## SilverFox

Hello Ian,

It would be interesting for you to discharge a cell that is giving you problems and not the capacity. Then charge it on another charger, then discharge it on the C9000 again to see what the other charger put back in.

Tom


----------



## wptski

Speaking of AAA's!

I just charged my first two, fairly new AAA PowerEx 1Ah cells which came out of my cordless mouse. I discharged both at 500ma on the C9000. One didn't even make a minute and the other when on and on, I didn't make a note of anything then.

I don't know which cell was which but one charged [email protected] min and the other charged [email protected] min. I've never run into a mismatch like this with AA's. Is one cell just odd or didn't it discharge?

Wait a minute, I did have one test where I discharged four AA's and two came out odd. The same test was repeated and they matched! :thinking:


----------



## jusko

Although Maha emphasizes the C9000 has the capability to revive old and long time stored batteries. I have tried many old and long time unused batteries. The C9000 just keeps showing HIGH or just doesn't recognize a battery is present. I have also tried discharging them first, but still no luck. But all these batteries can be charged sucessfully with other not-so-smart chargers.

I performed a 3-cycle mode for a pair of old Sony 1450mah cells the other day. No fan used, setting was 1000ma charge and 500ma discharge and then went to sleep. Next morning, one cell was doing fine for the cycle (2nd or 3rd, I forgot), but the other one was still in the 1st charging cycle showing 5xx mins, 84xx mah. Strange thing was that overcharged battery didn't feel very hot. I stopped the charger manually to prevent something bad from happening.

I would say the C9000 is not behaving consistently, very battery-condition dependent. May be its too smart. The original design concept is good but there may be some problems in the chip manufacturing. 

I think it would be a joke if a smart charger has to be helped with a fan, a timer or manual intervention to do its job.


----------



## wptski

I wonder when the C9000 does miss termination and shows a charge input many times the cell capacity but not overheating, is it really still charging? I used 600ma rate of four 1.8Ah cells trying to force it to miss. One cell did and after 20 hrs and 6C, I pulled the cell but it never got warmer than 125F or so and actually cooled a bit! Makes me wonder if it's doing nothing really and was just heated by convection from the charger. Then again the charger wouldn't be warm if it wasn't charging!! Very confusing.


----------



## NiOOH

wptski said:


> I wonder when the C9000 does miss termination and shows a charge input many times the cell capacity but not overheating, is it really still charging? I used 600ma rate of four 1.8Ah cells trying to force it to miss. One cell did and after 20 hrs and 6C, I pulled the cell but it never got warmer than 125F or so and actually cooled a bit! Makes me wonder if it's doing nothing really and was just heated by convection from the charger. Then again the charger wouldn't be warm if it wasn't charging!! Very confusing.


 
Confusing indeed. Overcharging at 0.33C by this amount should heat the cell much more than that. 20 hours may even force it to vent. Very strange. How is the cell now, i.e. could you measure any decreased capacity, or any other signs of one-time severe overcharge.


----------



## jusko

May be the cell which missed termination had already been stopped charging but the reading still went on. Besides the overcharging cell was not not, the voltage was quite normal around 1.4v to 1.5v.


----------



## NiOOH

Voltage is not a good indicator, I mean a cell showing around 1.5 V may still be charging. Bill can you connect the test cell again using the scope?


----------



## SilverFox

Hello Jusko,

I wonder if you could check something for me.

Take one of your cells that won't charge on the C9000 and discharge it. Then charge it on a charger that will charge the cell. Finally do another discharge on the C9000 and report back the labeled capacity of the cell and the discharged capacity. 500 mA would be a good discharge rate to use. Also, keep rough track of the charging time on the other charger and it would be good to know the charging rate.

I agree with NiOOH. This is very strange behavior. Continual charging should heat the cells up.

Two possibilities come to mind. The charger may not be actually charging, but since it seems to work on other cells, this seems unlikely. The other possibility is that Maha did not have a good selection of crappy cells to choose from during their testing. I suppose there is a certain irony in us having the best flashlights and the crappiest cells...

Tom


----------



## wptski

NiOOH:

I marked the cell but I'm not sure where it is right now! Yes, causing a missed termination and scoping it is something that's on my list to do. I don't know how much should be seen at .33C for 20 hrs. I know SilverFox mention a manufactureres claim of 1C should be 104F. I took a 2.3Ah cell at 1C on a Duratrax ICE and the max was 106.8F

This brings up a OT point! It's been some time since I looked at the manuals for the Triton and ICE. Rereading, I find that both use a bit confusing ZeroDeltaV with a sensitivity setting in mv. In fact, somebody posted a question about this somewhere. That means a variable peak/zero voltage termination. Now, is that the same as -DeltaV? It kind-of/sort-of sounds like it!


----------



## SilverFox

Hello Bill,

I believe it is the same and is also called peak voltage detection on - delta V. This is not to be confused with peak voltage detection incorporating the slope of the charging voltage line.

Tom


----------



## wptski

SilverFox said:


> Hello Bill,
> 
> I believe it is the same and is also called peak voltage detection on - delta V. This is not to be confused with peak voltage detection incorporating the slope of the charging voltage line.
> 
> Tom


Tom:

I think that one of the two refered to it as Zero Peak Voltage.


----------



## TorchBoy

SilverFox said:


> I agree with NiOOH. This is very strange behavior. Continual charging should heat the cells up.


How much heat will there be? 0.33C for a 1000mAh cell is 330mA. At 1.5V is 0.5W. Next question, how much of that 0.5W will convectional, conductive, and radiative cooling remove? The cells are warm, yes? But not hot because they are being cooled as they go. MHO is that they are being charged, and maybe damaged in the process.



SilverFox said:


> I suppose there is a certain irony in us having the best flashlights and the crappiest cells...


 

The two AAA cells that I managed to put through the break in finally finished so I discharged them at 400mA and got 615 and 619 - the same as in the break in 0.2C discharge. But now I can't recharge them because they both read HIGH (again).  Yes, I can dig out another charger to give them a bit of cycling (discharging on the C9000 to get capacity readings) but like jusko said, this charger is supposed to be good at this sort of thing.

Forgive me if it's a stupid question but why is it checking impedance on break in mode? This is the mode we'll be using if we want to rejuvenate stubborn cells. I *should* be able to use it for this, even if the cells are too poked to charge normally.

I've even contemplating putting a resistor across the battery terminals during the impedance test.


----------



## TorchBoy

SilverFox said:


> Hello Verge,
> 
> The standard IEC charge is 16 hours at a 0.1 C rate. The standard discharge for capacity is at 0.2 C. This usually results in a 5 hour discharge (300 minutes), however it looks like your cells had more than their rated capacity. This means that it took over 5 hours to complete the discharge.
> 
> Tom


I've noticed, like others, that these cells (AAA in my case) discharge very slowly when nearing the end of their discharge, and this can cause much longer discharge times that the 5 to 5.5 hours expected. Is that because the C9000 ramps down its discharge rate to ensure fully flattened cells by 1.00V or because of the alleged high impedance of the cells?


----------



## SilverFox

Hello Ian,

The impedance check is to rule out charging Alkaline cells. 

Most of the heat that is produced during the end of the charge comes from a chemical reaction within the cell. I am not sure how you figure the wattage equivalent for that.

I have no idea why the current drops at the end of the discharge cycle. I am sure it has something to do with the programing, but I don't understand it at all. 

Tom


----------



## digitor

SilverFox said:


> I have no idea why the current drops at the end of the discharge cycle. I am sure it has something to do with the programing, but I don't understand it at all.
> 
> Tom



Earlier in the thread, willcheuh wrote:

_I think I've a good explanation for you. During both charging and discharging, the voltage is read "offline" which means they are taken with the current off. 

Say your battery has a higher than usual resistance. When the current is on, it might cause the battery voltage to drop (treating the battery as a virtual resistor - this is really not the case it's best simulated by a resistor and capacitor in parallel). This voltage drop can cause the charger to unable to pull the set current as the voltage becomes too low (the circuit is only designed to reach set current when battery voltage is >0.9V). 

The Good news is capacity calculation is always made with the "real" current. The software does an integration of current with respect to time every two sceonds. So your capacity reading is still accurate. 

William_

I think this is the explanation.

Cheers


----------



## SilverFox

Hello Digitor,

Welcome to CPF.

Yes, I read that, however, I still don't completely understand the need for it...

Tom


----------



## digitor

SilverFox said:


> Hello Digitor,
> 
> Welcome to CPF.



Thanks! I've been reading hard since I ordered my C9000 just before Christmas, hopefully they'll be in Oz in a week or so.



SilverFox said:


> Yes, I read that, however, I still don't completely understand the need for it...
> 
> Tom



An unintended effect I guess, but that seems to be why the discharge current tapers off for some cells towards the end.

Cheers


----------



## jusko

Hello Tom,

I have done 2 tests per your request in post #237.

1. Two "Super 2000" AA with min. 1900mah. Always show "HIGH" with whatever modes of C9000. Charged in another charger at 500ma for some 5+ hours. Discharge capacities were 1530mah and 1562mah. This result was quite reasonable given the cells are 6 or 7 years old. I have 4 pieces of this cell that all show "HIGH" in C9000 but chargeable in other chargers.

2. Two "REX Ultra 700" AAA with min 650mah. One shows "HIGH" and the other causes the LCD on and off. Charged in another charger at 200ma for some 4+ hours. Discharge capacities were 506mah and 471mah. I have 8 pieces of this cell, 5 show "HIGH", 3 cause the LCD on and off. They are also 6 or 7 year old and I know they are of inferior quality.

I agree with another user that the impedance check should be relaxed or at least be neglected in the break-in mode, so that some old batteries can still be charged.

But the most bothersome problem is missed termination. I have experienced several times and more with a fan, that even new and good quality cells such as the Eneloop and Uniross Hybrio missed termination. I would say this C9000 is not performing consistent and stable enough.


jusko


----------



## SilverFox

Hello Jusko,

Thanks for checking that for me.

If cells are considered "dead" when they can only provide 80% of their original capacity, or less, your cells are very close to being "dead." It is interesting that the other charger will charge them...

I agree that the missed termination issues are more important, but find the impedance rejection issue "interesting."

Tom


----------



## TorchBoy

*Re: Maha MH-C9000 SUPPORT Thread*



willchueh said:


> *Using the CYCLE mode, why do I see a "0 mAh" capacity on the screen? What happened to the saved battery capacity?
> *
> A CYCLE is consisted of:
> Charge > 1 Hour Rest > Discharge > 1 Hour Rest (repeats for programmed number of times)
> The discharge capacity is saved into the memory at completion of discharge but cannot be reviewed until that cycle is completed (after the 1 hour rest). During the rest, a zero capacity is displayed.
> 
> During this period, all previously completed cycle data can be viewed, but not the most recent cycle. It will become available after that particular cycle is completed.
> 
> Cycle data can be accessed anytime after completion of the first cycle by using the "UP" and "DOWN" keys.


I've just tried using CYCLE mode for the first time and after the hour rest period (WHY???  ) I pushed the UP and DOWN keys to read the capacity of the cycle... and got "*5 5MAH*". Yes, that's a space in the middle. Where did the middle digit of the capacity figure go to? That digit normally displays just fine.

(Did a search for all sorts of things but I haven't seen this problem mentioned anywhere.)

I'm beginning to have issues with this thing's issues.


----------



## meeshu

Most likely a LCD and/or a LCD driver/decoding circuitry problem.  

Someone else in another thread is also having LCD display problem (faint characters).


----------



## TorchBoy

Thanks meeshu. I found that other thread, and maybe it's the same thing - perhaps it was a 1 and just a couple of segments weren't showing. If it happens again I'll take a photo like "too" too.


----------



## SilverFox

Hello Ian,

I have also seen one case of a dropped digit. I don't remember the exact circumstances, but it was not repeatable. I do remember it was on a 3 cycle run, and on cycle 2 one of the slots displayed dropping the second digit from the right.

I have not seen it since, but I also have not done that many cycle tests.

Tom


----------



## TorchBoy

Thanks Tom. Interestingly, mine is repeatable, as shown in the photo I took this time. https://www.candlepowerforums.com/posts/1820138&postcount=9

Any comments, William?


----------



## willchueh

Does the power up LCD test normal (i.e. all symbols show correctly and digit display cycle from 0000 to 9999)? 

William




TorchBoy said:


> Thanks Tom. Interestingly, mine is repeatable, as shown in the photo I took this time. https://www.candlepowerforums.com/posts/1820138&postcount=9
> 
> Any comments, William?


----------



## TorchBoy

The last time I powered up I didn't notice any problems at all. That slot has now finished cycle 2 and it shows the capacity for that cycle as 519mAh, with the centre digit perfectly clear, but the first cycle figure is still "5 5". How weird.

Edit: No problems with startup routine.


----------



## summerwind

Will,
i think it's fair to say we have put the demand on you, and in return you have answered practically every question and concern.
my question is now, will the C9000 be getting revamped in the near future?


----------



## summerwind

any news?


----------



## digitor

At last! My C9000 shipped today from the Australian distributor - it should arrive tomorrow.

It'll be getting a good workout for the next few weeks, first I plan to work through all my older cells, to see if I can sort out some reasonably well matched sets for use as backups for my flashguns.

Cheers


----------



## jusko

No way for old cells. I first also thought that the C9000 can revive my old cells, but it can't. It just can't charge old cells in whatever modes, including the BREAK IN mode . It just keeps showing HIGH or the LCD on and off. It is designed for good and healthy cells only.


----------



## verge

My MH-C9000 did great BREAKIN job on my old Kodak 1600mAh (4xAA) and 1700mAh (4xAA) batteries.


----------



## digitor

So far so good for me as well - I've just been through refresh & analyse on 16 of my 5 year old Mitsubishi 1600mAH AA's - about half of them are over 85% of their rated capacity, and that's at a 500mA discharge rate. Highest was 92% (1473 maH).

These must be pretty good cells, they recycle my flash guns quicker than the new 2500 mAH cells I've got.

I'll ty a break-in on the lowest four (around 70%) soon, to see if they improve.

Cheers


----------



## LuxLuthor

Whew...I just finished reading this whole thread...some of the posts are very detailed, especially SilverFox's Post #216. I learned so much that I didn't know that I didn't know. A big thanks to everyone posting.

I'm still not sure if I should have bought this C9000 model, since apparently the model I got in January *#OFAB02 *is already outdated by a better version. I still have to read at least two other mega threads I saw...and my eyes are already bleeding.


----------



## jusko

My C9000 version is 0FAB02. I found that the discharge capacity is the highest in slot 2, followed by slot 1, 4, 3. I had swapped the cells and charged in different slots, but the discharge capacity was still in that order. No big deal, the biggest difference is only about 2.4 percent.

jusko


----------



## wptski

jusko:

On the 0G0B01 version it seems to the highest discharge capacity on slots 3, 2, 1 and then 4.


----------



## jusko

Thanks Bill for your info.

Best Regards
jusko


----------



## clewis5431

I am new to this forum and I do not know what I am doing. So please forgive me if I sound ignorant or maybe a little bit stupid.

I need to know if I am wasting my time by using a work-around to save time in getting new batteries on line.



I have both a MH-C9000 and an Mh-C801D charger. When I get new batteries and use the break-in mode of the 9000 it takes me one week (for 16 new batteries) to form-in the new batteries using the brake-in mode.



There seems to be a intense, if not passionate, feeling that all new batteries should be completely discharged before subsequent charging for first use.



What I do, to save time, is to put the first four in the 9000 and set it to break-in mode. It will be thirty nine or forty hours before the process is complete. It would take me a week to break-in all the new batteries using this method. Instead I put in the first four in the 9000. I then put a fully charged battery into slot one of the 801D. I wait until the info bar changes to discharge I then put a new battery into slot two. They are now both in the discharge mode.



I then remove the previously fully charged battery from slot one, which is now being discharged, and replace it with one of the new batteries. I then place the remaining new batteries into slots three through eight. At this time all batteries are being discharged.



When this process is completed, I have saved many hours of conditioning time. Or, maybe it did not accomplish anything compared to the normal break-in procedure. 



Please advise,

Charles Lewis


----------



## TorchBoy

Charles, why don't you just start using them? They may perform a little better after a break-in but it's not like they'll immediately and permanently die if you don't do it. Who's promoting this feeling you talk of?


----------



## SilverFox

Hello Charles,

Welcome to CPF.

We are passionate about forming a new cell. The Break-In mode does this, along with a standard discharge to give you the capacity of the cell, and followed again by another standard charge.

The most important step in this is the first 16 hour charge.

I like to know the initial capacity, but you can get close by doing a 500 mA discharge sometime early in the cells life.

Let's suppose that you are just interested in getting the cells into service as fast as possible. I will take you through it step by step...

We will look at 2700 mAh cells for the example, but the same process would be used for all capacities.

1. Brand new cells will have some charge on them, but won't be fully charged. Your method of using the 801D will work fine, or you can set the C9000 to discharge at 1000 mA. Either way, you start with discharged cells.

2. Select Break-In on the C9000 and enter in the capacity of the cells you are breaking in.

3. Set a timer for 16 hours.

4. When the timer goes off, the cells should be fully charged and in a Rest mode. Pull the cells off the C9000 and use them.

That is the quickest way. To time this, you would put cells in the C9000 before you go to bed and discharge them. In the morning, say around 6:30, you would start the break in and the cells would be fully charged by around 10:30 that evening. You would then swap the cells out and begin the discharge on the next batch. 16 cells would take you 4 days. 

If you are interested in the standard discharge data, it takes a little longer. You now have to add a 1 hour rest plus a 5 hour discharge. The total time comes up to around 22 hours. If you start at 10:00 in the evening, they should have gone through the standard charge, rest, and standard discharge by 8:00 the next evening. Once again, it would take 4 days to do 16 cells. The only catch to this is that you have to read the discharge data before the end of the rest period at the end of the discharge. If you miss the reading, you have to wait another 16 hours until the charge has finished before you can view the data.

The full Break-In cycle involves a 16 hour charge, rest for 1 hour, a 5 hour discharge, rest for 1 hour, and ends with another 16 hour charge. As you can see, this works out to around 39+ hours, it usually takes a little longer, but is a great way to break in your cells. With this method, you start at 7:00 in the morning and two days later, they are done. 16 cells will take 8 days.

The Break-In is the best way, but there are other options you can use.

Once again let's look at 2700 mAh cells. 

You can use the cycle mode and select 5 cycles, charging at 1500 mA, and discharging at 1000 mA. Each cycle would involve about 1.75 hours charging, rest for 1 hour, about 3 hours discharging, and once again rest for 1 hour. That comes to a total of 6.75 hours per cycle, or 33.75 hours for the whole 5 cycles. If you time things right, you could be finished with all 16 cells in 6 days.

With this method, you need to keep a close eye on the first couple of charges. New cells often give termination algorithms false signals. Sometimes the charge ends early, and other times the termination signal never appears. I don't recommend this method, because of these issues.

We are still looking at a long time, so here is a method that is a compromise. Put the cells in the C9000, discharge them at 1000 mA, then charge them at 200 mA. With 2700 mAh cells, this will take about 14 - 15 hours.

As you can see, all of the methods take some time to complete, but you will find that your cells will perform better and last longer because you took the time to break them in.

Tom


----------



## Codeman

Tom, that post belongs in a sticky thread all by itself! :bow:


----------



## dekelsey61

Hi Tom,
I have a question for you about th C9000 charger and the break-in mode.
If you put a battery in the charger to do a break-in mode and the battery is about 75 percent full will the 1st charge cycle in the break-in mode hurt the battery? 16 hours would seem to over charge a battery which already has some charge in it. Or is the charge cycle in that mode so low that it will not harm the battery?
Thank you for your reply.
Dan


----------



## TorchBoy

OK, Tom is passionate about forming cells and the rest of us (me at least) just do what he says. How much of a difference does it make, Tom?


----------



## SilverFox

Hello Dan,

The 0.1C charge rate is suppose to be low enough that 16 hours of it does not do any harm. 

There is some controversy surrounding this. Some people feel that there is a possibility of damage even at this low a charge rate, however some battery manufacturers state that their cells can be left on a 0.1C charge for a year without problems. 

If we use heat as a metric to measure overcharge, I have not seen much of a difference between charging a discharged cell for 16 hours at 0.1C or charging a fully charged cell for the same period at the same rate. 

The purpose of the standard charge is to redistribute the electrolyte within the cell. That is more effective when charging a discharged cell, but can be accomplished, although not as effectively, by charging a charged cell.

Tom


----------



## SilverFox

Hello Ian,

Yes, I am the passionate one...  

The benefits that I have observed include:

Strong termination signal and no missed terminations.
Cells remain cooler during charging.
Capacity of the cell is repeatable.
When cells are used in a battery pack, the pack stays in balance better.
The voltage under load is slightly higher.
And, when done every 20 - 50 cycles, it tends to ward off "crap-cell-itus," and keeps the performance of the cell high.

Tom


----------



## TorchBoy

Thanks Tom. Now, if only the MH-C9000 actually allowed us to use the break in mode on old NiMH cells.


----------



## Codeman

SilverFox said:


> "crap-cell-itus"



Now you're just showing off, using them $5 technical words... :nana:


----------



## Power Me Up

TorchBoy said:


> Thanks Tom. Now, if only the MH-C9000 actually allowed us to use the break in mode on old NiMH cells.


As long as you do a full discharge on the cells first, you should be able to do a break in mode on them.


----------



## Daniel_sk

Any pictures of the DC adapter supplied with the charger? Because the description mentions: "Worldwide 100-240V switching adapter". I would like to order it from the US, I live in Europe and we have 240V (60Hz) and different plugs. I guess the aren't european plugs on the adapter?


----------



## TorchBoy

Power Me Up said:


> As long as you do a full discharge on the cells first, you should be able to do a break in mode on them.


You know, I think that actually used to work before my first two MH-C9000s did all the Termination Roasting on the poor cells. Now other chargers reject them, and they used to work fine. :sigh: The overheating was the straw that broke the camel's back perhaps. It gives me an excuse to buy more Eneloops.


----------



## GCBStokes

I finally got a chance to use my new Maha C-9000 Charger after getting it week ago. I'm really impress, as I am with the MH-C801D as well. The MH-C801D is a great charger and I can charge 8 batteries at one time and this makes it indispensable for my needs. However, I wanted the C-9000 to Charge, Analyze and for the Break-In (Forming Charge) Mode.

My first task on the C-9000 was to use the Refresh Analyze Mode on three sets of Titanium 2700 NiMH AA's. I have one set that give me great runtime in my Apex Headlamps, about 3 hours. 52 minute average. However, the other two sets give me between 3 hours 10 minutes & 3 hours 20 minutes runtime. It's still good runtime, but not nearly as good as the one set. So, I was think I'd do the Refresh Analyze Mode on them and match up the batteries and this should give me more consistence performance.

I have now completed the Refresh Analyze Mode and now will see it what I've do will improve the performance of the two sets of batteries that were giving me the inconsistent performance/runtime. And I do have a question regarding the performance of the charger itself. When performing the Refresh Analyze function, after the batteries were don't charging and then before the discharge, it went into the Rest Mode that is suppose to be one (1) Hour. However, it last 128 minutes. After the discharge mode and before recharging the Rest Mode lasted just about 128 minutes again instead of the 1 hours. Is this normal, or should I be concerned? 

Now I'm in the process of Forming (Braking-IN) 4 new sets of Sanyo 1000 mAh NiMH AAA's. I selected the 1000 mAh battery capacity when prompted for the capacity, and I was off and running. However, I have noticed that after the initial charge the battery capacity was reading out as 1420 mAh on my 1000 mAh AAA batteries. Is this anything to be concerned about?

Hay Tom, if you get this, I thank you for all the help you have been. I do believe if I have to keep coming to you for your help, advice and for answers, and I see that many look to you for answers, we are going to have to start referring to you as the "Godfather Of The Candlepowerfourm!" 

But I'll take help, advice and input from all, and thanks to all who help. The people here on candlepowerforums.com are wonderful, and I'm glade I got involved. You are great bunch of people. If you ever have a question regarding Wild Birds and/or Nesting Boxes, Wildlife and Forestry please feel free to ask and I'll help you out or get you the answers from one of many other scientists know or work with.


----------



## LuxLuthor

GCBStokes said:


> Hay Tom, I you get this I thank you for all the help you have been. I do believe if I have to keep coming to you for your help, advice and for answers, and I see that many look to you for answers, we are going to have to start referring to you as the "*Godfather Of The Candlepowerfourm!*"



Certainly the *Godfather of CPF-Battery section* fits.


----------



## TorchBoy

GCB, Tom (SilverFox) found that the new version of the MH-C9000 has a two hour break after charging to allow for a top-up charge but after discharging the break is still only one hour. 128 minutes for each sounds strange.


----------



## SilverFox

Hello GCB,

As Ian has indicated, the rest period after charge is 2 hours, but after discharge it is supposed to still be 1 hour. Perhaps you could check this again.

When charging, you always put more in than you can get out.

Thanks for your generous comments. It is my pleasure to help out when I can.

Tom


----------



## GCBStokes

Tom,

You guys are 100% correct.:sweat: What I was seeing is was:

Slot# 1 was still discharging and was showing 128 minutes, Slot# 2 was done discharging and was in the rest mode. I saw the 128 minutes thinking all batteries were in the rest mode for 128 minutes. Also when I'm looking at each slot, I now also see that when some are charging, others are still in the rest mode after the discharge mode. This is what was throwing me off.

When I look at each slot individually the rest period is 1 hours after discharge, and two hours after charging. Sorry guys, it was just a rooky mistake on my part... 

I just hope coach Tom gives me the change to work through my rooky mistakes and doesn't send me back down to the minor leauge, putting me back on the Titanium LCD 8 bay charger that I used before. :eeksign: 

Also, I found the answer as to why I was seeing battery capacity readings higher then what the batteries were rated on the Maha Web Site. I also found some answers to other question I had. :rock: 

http://www.mahaenergy.com/store/mhc9000faq.asp

*MH-C9000 Frequently Asked Questions* 

Using the BREAK-IN mode, I am seeing a charging capacity much higher than the capacity I programmed. Why is the battery overcharged? 

When using the BREAK-IN mode, the charger puts in 1.6 times the capacity of the battery (entered at the start of the charge). This does not cause any harm to the battery as the charging rate is very low (only 10% of the battery capacity). The increased total charging capacity compensates for energy lost as heat. This is the charging scheme recommended by International Electrotechnical Commission (IEC). 

*I am charging some older batteries and see that the charging capacity is much higher than the capacity I programmed. Why doesn’t the charger terminate correctly? *

The charger terminates by voltage and by temperature simultaneously. For certain older (and low quality) batteries, they do not produce the proper negative delta V signal (a small voltage drop at the conclusion of the charge) needed for the charger to stop. At the same time, the battery temperature failed to reach the termination limit as the charging rate was probably too low.

To address this issue, you should attempt to perform a BREAK-IN mode on the batteries first. You should also use a higher charging rate. 

*After the charge begins, why do I see an abnormally high voltage (~ 1.6V to 2.0V) on the screen? *

In the first few seconds, the MH-C9000 performs a proprietary “high impedance” check to filter out batteries unsafe to charge including non-rechargeable batteries. During this time, a high current is applied and voltage measured to determine the impedance of the battery. 

The voltage will return to normal by the second time voltage data is displayed on the screen. 

*I am using the CHARGE mode. Why is the capacity different than my battery capacity? *

The capacity displayed in any charging process is called the “charging capacity.” This is the amount of energy put into the batteries. This number does not equal to the battery’s capacity as it is dependent on the amount of charge already in the battery as well as the battery’s internal resistance. 

For example, a half used 2000mAh battery may only show a charging capacity of 1000mAh since the battery is half full. 

It is normal for the charging capacity to exceed battery capacity by as much as 30% depending on battery brand and charging rate. 

To determine the battery’s useful capacity, you must look at a “discharge capacity.” Such information is available in the REFRESH & ANALYZE, BREAK-IN, DISCHARGE, and CYCLE modes. Note that the battery is not recharged in the DISCHARGE mode. 


*Is the MH-C9000 compatible with the new "low self-discharge" batteries (e.g. Sanyo Eneloop)? *

Yes. Follow the same charging rate recommendations for general NiMH batteries.


----------



## GCBStokes

Now I see that my new found information was at the beginning of the this thread all along! Good Grief!!!:hahaha:  

Another costly rooky mistake....:sigh:


----------



## wptski

Anybody "really" see the original C9000 or improved C9000 terminate for temperature? I mean for sure! I've had cells get over 150F and never shut down for high temperature. The temperature sensor is located at the negative end of the cell which is always cooler and the plastic area around the metal sensor is 15F less than the cell temperature too.

Tom(SilverFox) has had the wrapper melt at least one time and I believe that the cell would have to get above 160F for that.


----------



## Handlobraesing

willchueh said:


> EngrPaul,
> 
> I think I've a good explanation for you. During both charging and discharging, the voltage is read "offline" which means they are taken with the current off.
> 
> Say your battery has a higher than usual resistance. When the current is on, it might cause the battery voltage to drop (treating the battery as a virtual resistor - this is really not the case it's best simulated by a resistor and capacitor in parallel). This voltage drop can cause the charger to unable to pull the set current as the voltage becomes too low (the circuit is only designed to reach set current when battery voltage is >0.9V).
> 
> The Good news is capacity calculation is always made with the "real" current. The software does an integration of current with respect to time every two sceonds. So your capacity reading is still accurate.
> 
> William



615 min (6:48AM)

I have the latest version MH-C9000 and using the break-in mode, which starts in charge mode, I noticed a substantial discrepancy in cumulative capacity reading.

Set capacity = 2700mAh
Charge current defined = 270mAh
Charge current displayed =268mA, hovering around very close to 270mAh.

exactly 600 minutes later accordingly to the dispaly, it was reading 2410mAh, more than 10% off from the product of displayed current times elapsed time.

Why did 270mAh go unaccounted? Where is the error? Timebase, current readout or integration? How do I know the data can be trusted?


----------



## wptski

Handlobraesing said:


> 615 min (6:48AM)
> 
> I have the latest version MH-C9000 and using the break-in mode, which starts in charge mode, I noticed a substantial discrepancy in cumulative capacity reading.
> 
> Set capacity = 2700mAh
> Charge current defined = 270mAh
> Charge current displayed =268mA, hovering around very close to 270mAh.
> 
> exactly 600 minutes later accordingly to the dispaly, it was reading 2410mAh, more than 10% off from the product of displayed current times elapsed time.
> 
> Why did 270mAh go unaccounted? Where is the error? Timebase, current readout or integration? How do I know the data can be trusted?


If you look at the waveforms on a scope you'd see that actual maximum current isn't 2A to begin with and the duty cycled isn't what it's supposed to be either! I imagine that "somewhere" in these threads I have posted waveforms showing that.


----------



## SilverFox

Hello Handlobraesing,

When comparing constant current charging and pulse charging at the same charge rate, the constant current charger will always put more into the cell because the pulse charger is off part of the time.

Tom


----------



## wptski

SilverFox said:


> Hello Handlobraesing,
> 
> When comparing constant current charging and pulse charging at the same charge rate, the constant current charger will always put more into the cell because the pulse charger is off part of the time.
> 
> Tom


Tom:

What about the average current? On my scope the numeric value shown was a average reading but the catch is that it's affected by what timebase your using! A bit confusing.


----------



## N162E

Handlobraesing said:


> 615 min (6:48AM)
> 
> I have the latest version MH-C9000 and using the break-in mode, which starts in charge mode, I noticed a substantial discrepancy in cumulative capacity reading.
> 
> Set capacity = 2700mAh
> Charge current defined = 270mAh
> Charge current displayed =268mA, hovering around very close to 270mAh.
> 
> exactly 600 minutes later accordingly to the dispaly, it was reading 2410mAh, more than 10% off from the product of displayed current times elapsed time.
> 
> Why did 270mAh go unaccounted? Where is the error? Timebase, current readout or integration? How do I know the data can be trusted?



And this is based on the average how many tests?


----------



## TorchBoy

N162E said:


> And this is based on the average how many tests?


:huh2:

What does it matter how many tests it was based on, especially if he wants to know where the extra went to on that particular run? I say 90% duty cycle. It's a subject that has come up before.


----------



## wptski

TorchBoy said:


> :huh2:
> 
> What does it matter how many tests it was based on, especially if he wants to know where the extra went to on that particular run? I say 90% duty cycle. It's a subject that has come up before.


You can very well have cell to cell differences. I have sixteen PowerEx 2.7Ah cells that have been cycled a few times now. Charged in sets of four at 2A in three of the four sets, Slot#1 has always had the lowest input capacity! Discharge tests confirm this too!

EDIT: I looked at the wrong column which I had written down! All four sets, Slot#1 has always had the lowest input capacity.

This is what N162E is asking for.


----------



## N162E

TorchBoy said:


> :huh2:
> 
> What does it matter how many tests it was based on, especially if he wants to know where the extra went to on that particular run? I say 90% duty cycle. It's a subject that has come up before.


A burp in line voltage, bumping the charger, a short in a cell or any one of several occurrances could cause a variation. You can base an assumption on a single test but, conclusion must be repeatable. In actuality I would never base capacity on whaT I put into a cell, only on discharge.


----------



## Handlobraesing

The cumulative capacity displayed is *consistently lower* on all four slots on discharge cycle as well.

Discharge current dialed in: 540mA (as part of 2700mAh break-in cycle) 
Discharge current displayed: 520-530mA

Time elapsed: 315min

cumulative capacity displayed on one of the slots 2485 (and the remaining slots were 2500 +/- 30mAh)

Ideal cumulative discharge at 315min: 2835mAh
Expected reading based on display at 315min: 2730 to 2783mAh
real reading ~2500mAh 

2500mAh/(315min/60min/hr) = 476mA(5.25 hour average) 
11.9% error in discharge rate relative to programmed value, but I don't know where the error is.

Current reading, or maintained current, or integration? 

If the read current x elapsed time doesn't approximately account for the displayed mAh, what is the current used for internal mAh calculation?


----------



## willchueh

Handlobraesing,

Please read my reply earlier in the thread as well as this thread:
https://www.candlepowerforums.com/threads/162441

Both charging and discharging current shown are the actual current. However, it does not include a ~10% off-time in the duty cycle. The "effective" charging current is approximately 90% of the current shown (this value is known exactly - but I don't recall the exact number).

Capacity is calculated by integrating the the current over the time which is current is on. There is no error associated with the integration process.

William


----------



## TorchBoy

OK Bill, Fred, some guy comes along and says "Why am I only seeing 90% of what I expect" and anyone who has seen enough of this thread (and can remember that far back) immediately thinks, well, pretty much what Will Chueh wrote above. How many times does someone need to see only 90% of what they expect before they ask the question "why?" And IMHO I think it's quite acceptable to _conclude_ that a particular run only gave 90%. It's what the figures show, after all.


----------



## Handlobraesing

willchueh said:


> Handlobraesing,
> 
> Please read my reply earlier in the thread as well as this thread:
> https://www.candlepowerforums.com/threads/162441
> 
> Both charging and discharging current shown are the actual current. However, it does not include a ~10% off-time in the duty cycle. The "effective" charging current is approximately 90% of the current shown (this value is known exactly - but I don't recall the exact number).
> 
> Capacity is calculated by integrating the the current over the time which is current is on. There is no error associated with the integration process.
> 
> William


Could you update us with the eaxct value?

If the displayed current is 600mA, you're saying that the current during the on-cycle is 600mA, but comes out to be 540mA avg over the cycle? 

Would the electrochemical process see this as if being charged at 540mA, or 600mA? 

What is the integration period used for the display current?

I also don't understand the reasonfor any kind of pause period during the discharge cycle. I believe the IEC standards calls to record data until cell voltage drops to 0.9 or 1.0v under C/5 load.


----------



## Power Me Up

Handlobraesing said:


> Could you update us with the eaxct value?
> 
> If the displayed current is 600mA, you're saying that the current during the on-cycle is 600mA, but comes out to be 540mA avg over the cycle?


Yep - that would be correct.



> Would the electrochemical process see this as if being charged at 540mA, or 600mA?


As far as charging efficiency goes, I don't think there's all that much difference between the 2, so it'd be pretty much the same as charging at a constant current of 540mA.



> What is the integration period used for the display current?


Not sure exactly what you're asking here?



> I also don't understand the reasonfor any kind of pause period during the discharge cycle. I believe the IEC standards calls to record data until cell voltage drops to 0.9 or 1.0v under C/5 load.


The original C9000 measured the terminal voltage during the rest period, but the newer version reads the voltage under load.

I can't see much reason for the pause with the new version - I'd guess that it's probably just a leftover from the original design...


----------



## Handlobraesing

willchueh said:


> Handlobraesing,
> 
> Please read my reply earlier in the thread as well as this thread:
> https://www.candlepowerforums.com/threads/162441
> 
> Both charging and discharging current shown are the actual current. However, it does not include a ~10% off-time in the duty cycle. The "effective" charging current is approximately 90% of the current shown (this value is known exactly - but I don't recall the exact number).
> 
> Capacity is calculated by integrating the the current over the time which is current is on. There is no error associated with the integration process.
> 
> William





willchueh said:


> Concerning the questions above on MH-C9000:
> 
> 1) The displayed charging/discharging rate does not include a ~10% off-time. For example, when you set current to 2.0A, it will charge at 2.0A for 90% of the time and rest for 10%. Of course, the capacity reported includes this effect.
> 
> 2) Time base is quartz based and is not a significant source of error (for comparison, BC900 uses RC circuit which has a substantial errror).
> 
> 3) Capacity is calculated by integrating current over time.
> 
> BTW you can find these answers on the other C9000 threads.
> 
> William



As shown in page 13 of the Sanyo Twicell manual, it is documented fact that true current and time average current don't behave the same. The document says that you can't charge a battery at C/500 rate to replenish the battery,however it is possible if you were to use higher current pulse that would yield a time weighed average fo C/500

http://us.sanyo.com/batteries/pdfs/twicellT_E.pdf

So, if 200mA constant current x 16 hrs yields acceptable charge on a 2,000mAh, I would suspect that ~2,000mA x 10% duty cycle (200mAh 2 sec TWA) would result in an increase in charging efficiency, therefore overcharging far more than you would charging at true 200mA. 

A good experimental test would be to 

charge a drained 2,000mAh cell at 200mA for one hour from a bench supply

Take another discharged cell of the same kind, charge on MH-C9000 at 200mA setting until cumulative display reads 200mAh. 

Discharge both batteries at 200mA or so and compare the available capacity. If the latter shows significantly more available capacity, it would support my hypothesis of increase in charge efficiency.

I finally figured out figured out how to measure the duty cycle using a Fluke 87-5 (you need the 87-5, 189 might not do it) non-intrusively. You could also use an oscilloscope and compare the ratio of high and low part of the voltage as well. 

Figure out a way to hook up your DMM to the battery under charge, it's not hard. Make sure red goes to +, black to -. 

1. Turn 87-5 to AC mode, manually force range to 600mV.

2. Push the yellow button to activate low-pass. 
This will keep the high-freq PWM regulator noise from interfering with the result and it's not available on anything but 87-5

3. Push the Hz % button twice until it reads percent.

4. Set the trigger to + using the sound symbol button. the symbol is on lower left of the screen and it's EXTREMELY tiny.

5. Set the charger to 500mA. Give about 20 seconds. You should get ~22.7%. You'll notice that the ratio of whining sound vs off sound approximately corresponds to it.

Set the current to 200mA. You should get 9%.
Set to 2000mA, you should get 91.3% 

In all cases, the rhythm in audible whine vs silence is consistent with the instrument values. 

So, it appears the MH-C9000 controls the time weighed average current using maximum current and 0.5Hz PWM... 

You can check the duty cycle of discharge cycle the same way, but to get the 87-5 to display the duty cycle of discharge-load on, set the trigger to "-" since you're trying to capture the ratio of the "low" state. 500mA ~45%, 1000mA ~ 91%. 100mA didn't produce enough change in voltage level to trigger the counter.


----------



## Handlobraesing

Use + for charging, use - for discharging.
the upper right indicates low pass filter enable, which makes the meter ignore any input above 1KHz. 

Don't even try without the low-pass enabled or a meter without the filter as a Fluke 189(unless you're using an analog meter that's inherently deaf in high freq range) because it will pick up the ~15Khz used for the PWM and throw the reading all over the place.

By 90% on 10% off, I think william meant 90% of the on cycle... so for 1,000mA charge, it would be (1A/2A) x 0.9 =0.45

Because of the high peak current, when you try to do a discharge test on relatively depleted alkaline, it would instantly crash to "done" and give 0mAh available even on 100mA setting. The pulse current is high, so it would cause the voltage to collapse enough to set shut off the discharge process.


----------



## wptski

Handlo:

The C9000 has been out for some time, so there's lots of reading you can do. Duty cycle, pulse width, etc., all has been posted here. The Fluke 87V isn't the only Fluke DMM with the low pass filter, it's included in the Fluke 1587 too.


----------



## NightBandit

I just finished reading this entire thread (my popcorn ran out an hour ago) and I have so many numbers running through my head that I want to clarify one thing.

What is the best way to charge my cells for both performance and longevity (and yes, I have performed a proper break-in on my cells)?
From what I've gathered in this thread (if I've understood everything correctly), it would be:

1. Charge my cells at .5C (charges my cells to 90%).
2. Let my cells sit on the charger for two hours (to top my cells off the final 10%).
3. Immediately pull the cells off the charger (so that they don't overcharge).

Does this sound right or have I completely misunderstood everything that I've read over the past couple of hours?

Also, would there be any need (or benefit) to discharge my cells before I charge them?

Thank you,

NightBandit


----------



## Handlobraesing

wptski said:


> Handlo:
> 
> The C9000 has been out for some time, so there's lots of reading you can do. Duty cycle, pulse width, etc., all has been posted here. The Fluke 87V isn't the only Fluke DMM with the low pass filter, it's included in the Fluke 1587 too.



Ummm... ok.. but 1587 can't measure duty cycle. You're correct, albeit irrelevant.


----------



## wptski

Handlobraesing said:


> Ummm... ok.. but 1587 can't measure duty cycle. You're correct, albeit irrelevant.


The 87V can't test wiring insulation! They all target a certain segment of buyers.


----------



## Handlobraesing

wptski said:


> The 87V can't test wiring insulation! They all target a certain segment of buyers.



Because we were talking about wiring insulation?


----------



## wptski

Handlobraesing said:


> Because we were talking about wiring insulation?


No, I mean that they don't put every feature in one super DMM, I guess because nobody really wants to pay for a "full" featured DMM. Like 189, 87V and 1507 in one meter. Maybe more since there features like low impedance that some want, add the 117 to the list too.

Oh yeah, the 87V has frequency, duty cycle but no pulse width. You can calculate it though.


----------



## JasonCC

Just recieved this charger last week, and have one question which I've not been able to clarify despite reading these forums all week.
What is the purpose of having the "refresh and analyze" mode, as well as a "cycle" mode?
From what I can see, the "refresh and analyze" performs exactly the same function as the cycle mode set to 1 cycle. Or have I misunderstood the functions of each somehow?
If the above is true, why not just get rid of the refresh and analyze mode and simply do a single cycle?

Jason.


----------



## Anders

Hello Jason.

Read this thread to learn more about c9000.
(Silverfox greate review)


Anders


----------



## JasonCC

Hi

Thanks, but I already read that thread, and there's no clarification of my question in there (unless I missed it).

Jason.


----------



## SilverFox

Hello Jason,

Welcome to CPF.

On the original C9000, Refresh and Analyze did not include the top off charge, but Cycle did. In the improved C9000, I don't believe there is any difference between Refresh and Analyze and doing Cycle for 1 cycle.

Tom


----------



## Handlobraesing

Mine seems to have issues with AAAs. While discharging Duracell 1,000mAh AAs at 300mA, one slot suddenly read 3.99v, then the entire thing rebooted


----------



## TorchBoy

I've heard that there is a new version, 0G0D01. I'd like to know if the Cycle memory problem has been fixed.


----------



## crislight01

i've got the 0G0C01, when i put AAA choose the mode but then the charger shuts down..???

i try the AAA cells on another charger looks like they are dammaged(maybe the mh9000 rejects them automatically)


----------



## Gazoo

After pulling half of my hair out deciding on a new charger, last night I ordered a C-9000 from TD. I was thinking about ordering a charger that could charge C and D cells, but then I remembered the C-9000 can. I don't have a huge need right now for C and D cell charging but might in the future. But I do have a remote control that takes 4 C batteries so I also ordered four of the AA to C cell adapters. 

For batteries I did order a set of the Sanyo 2700ma's. I also placed a large order for Eneloops from Battery Bob to replace my aging GP 2300ma cells.

I am really looking forward to the C-9000. It will be interesting to see how well it can recover my GP batteries. Currently I am using a Rayovac 1 hour charger. It has served me well, but lately I don't think it has always been terminating properly. One of my cells has developed a ring and the top and another one has expanded slightly.

Anyway, I want to take a moment to thank Silverfox and everyone else that has provided input which helped me make a decision. I know the C-9000 isn't perfect, but it is a heck of a lot better than what I have now.


----------



## Codeman

Over the past few weeks, I've noticed that slot 1 sometimes doesn't recognize a AA cell. I don't have any troubles with it when charging AAA's, and the AA cells that do have troubles in slot 1 do just fine in the other 3 slots. With repeated insertions into slot 1, they will usually be detected eventually and charge without incident, so I suspect that something's wrong with slot 1.

Has anyone else seen this happen? I've got one of the earlier models from TD back in January.


----------



## wptski

Gazoo said:


> After pulling half of my hair out deciding on a new charger, last night I ordered a C-9000 from TD. I was thinking about ordering a charger that could charge C and D cells, but then I remembered the C-9000 can. I don't have a huge need right now for C and D cell charging but might in the future. But I do have a remote control that takes 4 C batteries so I also ordered four of the AA to C cell adapters.
> 
> For batteries I did order a set of the Sanyo 2700ma's. I also placed a large order for Eneloops from Battery Bob to replace my aging GP 2300ma cells.
> 
> I am really looking forward to the C-9000. It will be interesting to see how well it can recover my GP batteries. Currently I am using a Rayovac 1 hour charger. It has served me well, but lately I don't think it has always been terminating properly. One of my cells has developed a ring and the top and another one has expanded slightly.
> 
> Anyway, I want to take a moment to thank Silverfox and everyone else that has provided input which helped me make a decision. I know the C-9000 isn't perfect, but it is a heck of a lot better than what I have now.


Is that a typo? The only way a C9000 can charge a C/D is if you "somehow" connect it externally with wires, clips, etc. and you'll be limited to 4Ah maximum charge input. You'd have to remove/reinsert several times, depending on the cell's capacity rating.


----------



## Bones

Codeman said:


> Has anyone else seen this happen? I've got one of the earlier models from TD back in January.



I too have the first release, but haven't encountered the problem you've described.

I'm just wondering if it's mechanical rather than electrical.

Do your cells seem to fit as snugly in the problem slot as the others?

If not, do you have a slightly longer cell you could use to test whether the charger has a problem detecting it as well?

I've noticed, for example, that my Energizer 2500 cells are almost 1/8" longer than my trusty old Twicells.


----------



## Gazoo

wptski said:


> Is that a typo? The only way a C9000 can charge a C/D is if you "somehow" connect it externally with wires, clips, etc. and you'll be limited to 4Ah maximum charge input. You'd have to remove/reinsert several times, depending on the cell's capacity rating.



Yes I know. However I thought the supported capacity with the first version was 20AH, and with the second version it was reduced to 10AH?

Edit: Never mind. You are correct, the maximum charge input is 4AH. It will still serve my need so I can't complain.


----------



## Anders

I think it is also possible to do a break in cycle with any single 1,2 volts NI-MH cell up to 20A, connected with wires if using other sizes than AA and AAA. 

Anders


----------



## TorchBoy

Bones said:


> I've noticed, for example, that my Energizer 2500 cells are almost 1/8" longer than my trusty old Twicells.


Is that a typo? According to the Duracell and Energizer datasheets an AA cell can be from 49.2mm to 50.5mm long. I make that about 1/20" acceptable variation. Anything outside that wouldn't be an AA.


----------



## Codeman

Not everyone strictly follows the AA standard. I've seen cells vary by 1/8". Unfortunately, neither that nor a bent connector nor a dirty connector are the issue for slot 1 in my 9000. The failure to detect happens erratically with various cells, from Energizer 2500's to Duracell 2650's to Eneloops.

I've sent email to Maha, so we'll see what they say about it.


----------



## Codeman

Woo-hoo! Maha is sending me a replacement, so I won't even be without my 9000. That's customer service! :thumbsup:


----------



## barkingmad

Does Maha or anyone do an adapter so you can charge / analyse other NiMH cells in the C9000 (ideally not just magnets etc.)?


----------



## ronk1030

Just received my C9000 today. (0G0D01). I'm charging 2 AA's and I'm doing a Refresh / Analyze with one 850 mAh AAA Energizer. 

Let me know if this sounds right. I'm charging the AAA at 300, and I'm discharging at 600..

850 TIMES .33 equals 280.5 or 300

Discharge (300 times 2 equals 600)

Temp started at 83 degrees and went to 100 and now it is resting

AND a BIG THANK U for all of this info.


----------



## SilverFox

Hello Ronk,

Welcome to CPF.

Energizer recommends a 1C charge for fast charging in order to obtain a strong end of charge termination signal. 

The C-9000 will terminate at lower charge rates, but you run the risk of a slight overcharge. These slight overcharges will degrade the performance of the cell over time.

The other option is a 0.1C timed charge for 16 hours...

Tom


----------



## PegAir

So one question I've got, and haven't had an opportunity to test yet as my charger is very busy doing real work ... 

If I was to run the refresh/analyize at 0.1C would the Maha detect a termination signal, or time out at 16 hours .. or would it just get stuck in the charge state until it exceeded the default of like 8 amps I think?


----------



## Power Me Up

PegAir said:


> If I was to run the refresh/analyize at 0.1C would the Maha detect a termination signal, or time out at 16 hours .. or would it just get stuck in the charge state until it exceeded the default of like 8 amps I think?


It may or may not detect the end of charge.

If you want to charge at 0.1 C, you should use the Break-In function which runs the charge for a fixed period of 16 hours. (Followed by a 0.2 C discharge and then another 16 hour 0.1 C charge)


----------



## wptski

PegAir said:


> So one question I've got, and haven't had an opportunity to test yet as my charger is very busy doing real work ...
> 
> If I was to run the refresh/analyize at 0.1C would the Maha detect a termination signal, or time out at 16 hours .. or would it just get stuck in the charge state until it exceeded the default of like 8 amps I think?


I think that the max default is 4A. Even the original manual stated not to charge at a rate lower than .3C which proved to be too low. At .1C, it'll never terminate as it's sure to miss it. I can't remember if it ever had or has a max time limit for R/A!


----------



## SilverFox

Hello Bill,

A point of clairification...

I believe the maximum is given in Ah.

Tom


----------



## wptski

SilverFox said:


> Hello Bill,
> 
> A point of clairification...
> 
> I believe the maximum is given in Ah.
> 
> Tom


Tom:

Right, Amp hours!


----------



## N162E

PegAir said:


> If I was to run the refresh/analyize at 0.1C would the Maha detect a termination signal


Never Happen. I have tested several different AAs and not had reliable termination on charge under 700ma.


----------



## ronk1030

I bought a set of 350mAh AAA batteries from Harbor Freight for a buck to play with.

Now for the numbers...

Refresh and Analyze

I set the charge for 200 and the discharge to 100
Numbers while charging
2575mAh
199ma
1.4 volt

I don't understand how I could get 2575mAh out of a 350mAh Nickel Cadmium. 

Numbers when finish charging
338mAh
1.38 Volt


----------



## N162E

ronk1030 said:


> I bought a set of 350mAh AAA batteries from Harbor Freight for a buck to play with.
> I don't understand how I could get 2575mAh out of a 350mAh Nickel Cadmium.
> 
> Numbers when finish charging
> 338mAh
> 1.38 Volt


Sounds to me like missed termination.


----------



## PJbatman

I recently received my C9000 from ThomasDist and absolutely love it!!
I thought I would share my idea for a "best of both worlds" charging technique... I start with discharged cells (~2yr old 2000 mah AA for my first test), charge them @ 1C (2 A) with a cooling fan, let them sit for ~30 minutes for topoff charge, cool for a few minutes, then charge them again at 0.2C (400 ma). The reason I like this method is that it can be fairly quick, but also gets them very full. I tested this first charge test by letting them cool a few minutes and then discharging them at 400 ma and 3 of the cells discharged ~97% rated capacity! The last one just isnt done yet and I needed to use the charger for my next set, so I took it out, but it looked like it was tracking towards the same good result. I have always seen the drawback to fast (1C) charging was that the cells would just not get full, even if the peak detection work perfectly. So, that is why I like the 1C, followed by 0.2C approach. If I recall correctly, the 1C charges input ~1900 mah and the 0.2C charges put in another 350 mah...
My background is in RC cars for several years. My general thoughts on nimh charging are that peak detection charging is definitely a precision business and having trustworthy equipment is a must, like this unit. I think slow (0.1C) non-peak detectection will generally lead to longer runtime and overall life, but, it is no where near as fun as precise peak detection... The higher the charge rate in peak detection, the higher the voltage will be under load, and the charging process will be faster, but properly detecting the peak is more important. When charging my 2000 mah cells in this unit at both 1C and 0.2C, I feel like it was doing a great job detecting the peak, and not significantly overcharging...
I now, have 4 of my new 2850 mah Ansmann cells in for a break in cycle at 270 ma and I plan to pull them out after ~16 hrs. I discharged them 1A and then again at 0.4A to get them totally empty. 

I am very passionate about my batteries...now, I just need to create some plastic dowel adapters, so I can charge my 4200mah subC monster truck cells, too bad it has 14 cells and I could really use (3) more C9000s...

Take care guys and thanks for the great thread on this machine.


----------



## Turak

Can anyone tell me FOR SURE..... Silverfox maybe?

What changed between the 0G0B01 and the 0G0D01 or 0G0E01 (latest?)firmware revisions.

No guessing or I thinks....please. FOR SURE ANSWERS ONLY!

Will MAHA exchange one with older firmware for one with the latest firmware?

Also, what number/person have people been speaking to at MAHA to get their MH-C9000 exchanged?


----------



## SilverFox

Hello Pjbatman,

Welcome to CPF.

If you have time, you can just leave the cells on the charger and let the top off charge finish charging them. At the end of the charge there is a 2 hour 100 mA top off charge done before it drops down to a very low maintenance trickle charge.

Tom


----------



## SilverFox

Hello Turak,

The early units had termination issues when charging "crap" cells at low charge rates. It also had a few missed terminations when charging good cells at normal rates. 

The "improved" version, modified the end of charge termination algorithm and reduced the total mAh clock. It is now very difficult (but not impossible) to get the unit to miss a termination, but the downside is that the cells are charged to a slightly less state of charge.

You can check out the Maha web site at www.mahaenergy.com to find out contact information. When the "improved" version was introduced, they offered to exchange the older versions for the improved version, but you had to pay for postage shipping your unit to them. I don't know if this offer still stands.

Tom


----------



## BillP2R

If this has already been asked and answered, please excuse me.

Let's say we have a cell that is rated at 2000mAH that now tests out with a 1000mAH rating.

The next time the C9000 asks for the rating of this cell, what should the input be - 1000 or 2000? (I would think 1000, but I'm not sure.)

----------------------- Bill


----------



## SilverFox

Hello Bill,

Welcome to CPF.

If you have a 2000 mAh cell and it is testing out at 1000 mAh, you have a CRAP cell and need to recycle it...

NiMh cells go to CRAP when they drop below 80% of their initial capacity.

Now, if you have a 2000 mAh cell, and it is testing around 1600 mAh and you want to try to revive it with the Break-In mode, you would still set the capacity as 2000 mA.

Tom


----------



## TorchBoy

SilverFox said:


> NiMh cells go to CRAP when they drop below 80% of their initial capacity.


I'm sure I've seen tests where new cells got less than 80% of their rated capacity.


----------



## NiOOH

TorchBoy said:


> I'm sure I've seen tests where new cells got less than 80% of their rated capacity.


 
It is normal for brand new cells or cels that haven't been used fo a long time to show reduced capacity on the forst couple of charges.
Mind also, that the rated capacity is measured as a standard at 0.2C discharge current (this is 400 mA for 2000 mAh cell). At higher discharge currents the capacity decreases.

I assume that we are talking about good quality cells. Some cheap Chinese cells never even come close to their rated capacity.


----------



## Anders

Hello.

I don't know if it has been reported yet, but if you wan't to charge your cells with the default values you don't have to push any buttom.

Just press in the cells and leave them there, you can also feed the charger with cells then connect the cable.


Anders


----------



## jkraus

I purchased four Energizer 2500 mAh cells and applied the break-in mode to all four simultaneously. After the intial 16h 0.1C charge, their [charging] capacities during the rest period were were between 3601 and 3614 mAh. After that, they discharged at 0.2C, rested for an hour, and then started their final 16h charge.

I had a look at the charger just when that final charging had started and noticed that the battery in bay 1 had charged for 17 mins while the one in bay 4 had charged for 38 mins (despite the fact that I started the break-in mode for all simultaneously). Why this discrepancy in time? Can these small differences in apparent capacity make such a difference in timing?


----------



## Power Me Up

jkraus said:


> I purchased four Energizer 2500 mAh cells and applied the break-in mode to all four simultaneously. After the intial 16h 0.1C charge, their [charging] capacities during the rest period were were between 3601 and 3614 mAh. After that, they discharged at 0.2C, rested for an hour, and then started their final 16h charge.
> 
> I had a look at the charger just when that final charging had started and noticed that the battery in bay 1 had charged for 17 mins while the one in bay 4 had charged for 38 mins (despite the fact that I started the break-in mode for all simultaneously). Why this discrepancy in time? Can these small differences in apparent capacity make such a difference in timing?



The amount of charge put into the cells has absolutely no relevance to the time taken (when doing a forming charge) or the actual capacity of the cells - it's the discharge capacity that counts.

In this case, the discharge capacity of the cell that was in bay 1 was probably about 160 mAh less than the one in bay 4, so it would have taken less time to complete the discharge.


----------



## jkraus

Power Me Up said:


> The amount of charge put into the cells has absolutely no relevance to the time taken (when doing a forming charge) or the actual capacity of the cells - it's the discharge capacity that counts.
> 
> In this case, the discharge capacity of the cell that was in bay 1 was probably about 160 mAh less than the one in bay 4, so it would have taken less time to complete the discharge.



That indeed was the case. That lower capacity battery only delivered 2212 mAh. Pretty poor for a brand new 2500 mAh cell.

The 2212 reading related to the discharge as part of the break-in mode. This is followed by another 16h charge. I then discharged again and the capacity had increased to 2292 mAh. 

What does this tell us? The capacity of a new battery indicated on the display after running the break-in mode is pretty useless as it gives you the capactiy after half the forming procedure (i.e. the first of two slow charges).

I wonder whether I can increase the capacity further by running another break-in mode. Or should I try the cycling method?


----------



## wptski

Power Me Up said:


> The amount of charge put into the cells has absolutely no relevance to the time taken (when doing a forming charge) or the actual capacity of the cells - it's the discharge capacity that counts.
> 
> In this case, the discharge capacity of the cell that was in bay 1 was probably about 160 mAh less than the one in bay 4, so it would have taken less time to complete the discharge.


"no relevance to the time taken"?????

What time taken?? Break-in is a 16 hour charge at .1C and that's it!


----------



## TorchBoy

Power Me Up said:


> The amount of charge put into the cells has absolutely no relevance to the time taken (when doing a forming charge) or the actual capacity of the cells - it's the discharge capacity that counts.


I too thought that was weird. Perhaps you meant the amount of charge put into a cell during a forming charge has no relevance to the actual capacity... but even then... yes it does. It should end up about 1.6 times the capacity.


----------



## wptski

TorchBoy said:


> I too thought that was weird. Perhaps you meant the amount of charge put into a cell during a forming charge has no relevance to the actual capacity... but even then... yes it does. It should end up about 1.6 times the capacity.


I'm with you on the even then part too!


----------



## Power Me Up

jkraus said:


> That indeed was the case. That lower capacity battery only delivered 2212 mAh. Pretty poor for a brand new 2500 mAh cell.



It's quite normal for "new" NiMH cells to require a few cycles to reach maximum capacity. (I say "new' because they may have been sitting on the store shelf for quite a while before you bought them)



> The 2212 reading related to the discharge as part of the break-in mode. This is followed by another 16h charge. I then discharged again and the capacity had increased to 2292 mAh.
> 
> What does this tell us? The capacity of a new battery indicated on the display after running the break-in mode is pretty useless as it gives you the capactiy after half the forming procedure (i.e. the first of two slow charges).


It's still handy to know since you can see how much of an improvement the second break in charge gave if you do a discharge afterwards as you have done.



> I wonder whether I can increase the capacity further by running another break-in mode. Or should I try the cycling method?


I'd say to try another break in charge followed by another discharge if you've got time and just see how that goes. If you're in a rush, you could put the cells through a few cycles, or even just start using them once you've recharged them. If you decide to put them straight into service, you can always do a refresh and analyze after they've been used a few times to see if they've improved any further.

Keep in mind that Energizer 2500 cells have a very bad reputation for developing high self discharge after only a relatively low number of cycles. I'd recommend taking them back for a refund, but the store probably won't take them back now that they've been opened...


----------



## Power Me Up

wptski said:


> "no relevance to the time taken"?????



In the context of the question, yes.



> What time taken?? Break-in is a 16 hour charge at .1C and that's it!


Exactly - I probably should have been a bit more specific with what I said, but it looks like jkraus understood what I meant anyway...


----------



## Power Me Up

TorchBoy said:


> I too thought that was weird. Perhaps you meant the amount of charge put into a cell during a forming charge has no relevance to the actual capacity... but even then... yes it does. It should end up about 1.6 times the capacity.


The amount of charge put into the cell during a break in charge does indeed tell you nothing about the actual capacity of the cell under test.

You could put in a 2000 mAh AA cell alongside a 2500 mAh AA cell, set the charger for a break in with a capacity of 2500 mAh for both cells and it would put the same amount of charge into both cells.

What it should do is put in 1.6 times the capacity that you tell the charger the cell is capable of holding.

In actual fact, the C9000 puts in 1.44 times the entered capacity due the fact that actual average charge and discharge rates are 90% of the selected rate:

2500 x 1.6 x 0.9 = 3600


----------



## wptski

Power Me Up said:


> In the context of the question, yes.
> 
> Exactly - I probably should have been a bit more specific with what I said, but it looks like jkraus understood what I meant anyway...


Nothing non-specific, just incorrect.


----------



## Power Me Up

wptski said:


> Nothing non-specific, just incorrect.


How so?


----------



## wptski

Power Me Up said:


> How so?


Reread from Post #346 on again. Your statement is questioned twice.


----------



## Power Me Up

wptski said:


> Reread from Post #346 on again. Your statement is questioned twice.



Yes...

But in what way is my statement actually wrong?


----------



## wptski

Power Me Up said:


> Yes...
> 
> But in what way is my statement actually wrong?


"Time taken" when refering to break-in charge! It's a 16 hr timed .1C charge. Your phrasing it as "time" is variable and that's incorrect.


----------



## Power Me Up

wptski said:


> "Time taken" when refering to break-in charge! It's a 16 hr timed .1C charge. Your phrasing it as "time" is variable and that's incorrect.



Ah... Now I see what you're getting at.

I don't believe that my statement was actually wrong - even if you read more into it than I intended. I do apologise for any misunderstanding for not being totally clear.

Would you have been happy with the following statement:

The amount of charge put into the cells has absolutely no relevance to the time taken when doing a forming charge *(because a forming charge is for a fixed period of 16 hours at 0.1C)* or the actual capacity of the cells - it's the discharge capacity that counts.


When I originally wrote the statement, I was actually referring to the amount of time taken that jkraus was asking about, but I added the bit in brackets to try to prevent any possible confusion in case someone read it and thought that I was also referring to normal charging. Again, my apologies for any confusion caused by not being totally clear.


----------



## Mitch470

*LaCrosse BC-900 Better?*



Mike abcd said:


> I still understand that as not being able to view the result of the LAST discharge cycle until 1 hour after the LAST discharge cycle completes.
> 
> That's just wrong. You have the capacity measured in the dischage test. Why wait an hour to provide it to the user? The rest period isn't going to change the result.
> 
> Mike


 
Mike,

The LaCrosse BC-900 shows the Discharge Capacity as soon as its calculated after the Discharge and keeps it available until the end of the 2nd Charge phase when the battery is removed.


----------



## TorchBoy

Power Me Up said:


> Would you have been happy with the following statement:
> 
> The amount of charge put into the cells has absolutely no relevance to the time taken when doing a forming charge *(because a forming charge is for a fixed period of 16 hours at 0.1C)* or the actual capacity of the cells - it's the discharge capacity that counts.


Don't know about Bill but I wouldn't be.

The amount of charge put into the cells *is* related to the time taken when doing a forming charge *because* a forming charge is for a fixed period of *16 hours* at *0.1C*. 

I agree that it doesn't necessarily have anything to do with the actual (discharge) capacity, since on an MH-C9000 it's the expected capacity that's entered by the user that the C9000 calculated the 0.1C charge rate at.


----------



## Power Me Up

TorchBoy said:


> Don't know about Bill but I wouldn't be.
> 
> The amount of charge put into the cells *is* related to the time taken when doing a forming charge *because* a forming charge is for a fixed period of *16 hours* at *0.1C*.



OK. Perhaps, what I should have said was:

The amount of charge put into the cells has absolutely no relevance to *determining* the time taken when doing a forming charge (because a forming charge is for a fixed period of 16 hours at 0.1C) or the actual capacity of the cells - it's the discharge capacity that counts.

My original statement should have been taken within the context of the question that it was originally answering. 



> I agree that it doesn't necessarily have anything to do with the actual (discharge) capacity, since on an MH-C9000 it's the expected capacity that's entered by the user that the C9000 calculated the 0.1C charge rate at.


Good - at least we agree on that!


----------



## meeshu

So. When is the C9000 going to have its LCD changed and firmware modified so that battery charge/discharge status is displayed for *all* slots *simultaneously* (similar to La Crosse BC-900 display)?:candle:


----------



## Power Me Up

meeshu said:


> So. When is the C9000 going to have its LCD changed and firmware modified so that battery charge/discharge status is displayed for *all* slots *simultaneously* (similar to La Crosse BC-900 display)?:candle:



I wouldn't be holding my breath if I wer you - I'd be surprised if it ever happened, but you never know...

Probably more likely that someone else will come out with something better that has all of the best feature of the C9000 and the BC900 in one unit (or maybe even better)

MrAl is working on a chip that can be used in a DIY project to build a computer controlled charger:
https://www.candlepowerforums.com/threads/175281


----------



## WDG

powergnome said:


> ...wont charge a couple of "Kaito" 1300 mAh battery that came with Kaito radios...


 
I have these, and they charge fine for me. I bought my radio within the last month, so I'm guessing the button is different on mine. These cells only came up to about 1050 after a couple break-ins and five cycles. What the eck... They were included, so I'll use them 'til I can't stand them.

(OT) BTW, I'm still not understanding what the charge timer should be set at on this radio (KA1102). The manual leaves far too much to guesstimation for my tastes. Is it a simple timed charger, or does it have some termination ability?



powergnome said:


> The recessed slots on the positive terminals is suppose to be a "safety design", but it looks like they may be a tad "too recessed" for some batteries.


 
When I tried my ancient Energizer 1200 cells, they would not make contact. These cells have a button with a large "shoulder" that keeps them from extending into the recessed slots. They were crap cells, so I just tossed them.



powergnome said:


> ...I can barely get AAA batteries to "click into" and to hold and stay within their slots.


 
The slightly rounded bottom of the AAA's I've had seems to be the culprit. I've noticed the Eneloop AAA's are not exactly what I would call a solid fit, but I've not had any of them pop out, yet.


UPDATE ON THE KAITO KA-1102 CHARGING: I did some testing to discover how much charge was being put into the cells using this radio's internal charging. I first did a 100mA discharge on the supplied batteries in one of the C9000's, then set the radio's charger for one hour (it's minimum charge time.) Then I did a second discharge in the same C9000 to see how much juice was actually being put in. 

Two of the batteries came in at about 280mAh, and the third was about 290mAh. So it looks like a five hour charge will be just about right for the supplied 1300mAh batteries, and a seven hour charge for Eneloops, assuming exhausted batteries. Currently, I'm charging in the radio for normal use, but cycling them monthly in the C9000's to try to keep them in good condition. 

I plan to do a bit more testing to learn how much charge is left when the various segments of the 1102's battery meter change, but I suspect it's going to end up being guesstimation at best, dependent upon what cells are in it. Safest will be to charge when the radio shuts down, or remove the cells and charge them in a proper charger.


----------



## wildfire305

Has anyone tried connecting c and d batteries externally with wires and successfully charged them? Or am I just Crazy for thinking that it's possible?


----------



## GaryF

wildfire305 said:


> Has anyone tried connecting c and d batteries externally with wires and successfully charged them? Or am I just Crazy for thinking that it's possible?



It should be possible, but the C9000 is limited to 4000 mAh total charge, so you may have to remove and reinsert the battery several times to get a full charge. Also, you are bypassing some of the chargers thermal protection by moving the battery away from it. It might be better to get a charger made to handle the bigger cells.


----------



## wildfire305

The protection! Doing what i proposed would make the product completely unsafe. That's a good point. I think i'll just drop the D-cells and buy AA adapters.


----------



## fourbeer

I charged three sets of batteries in Break-in Mode. Each time I started the break-in mode, the charging voltage of one of the cells was very low (0.14V). 

I pulled out all the batteries and started over. All charge voltages were now 1.34V.

Is this expected or is there something wrong with my charger?

-Thanks.


----------



## Power Me Up

fourbeer said:


> I charged three sets of batteries in Break-in Mode. Each time I started the break-in mode, the charging voltage of one of the cells was very low (0.14V).
> 
> I pulled out all the batteries and started over. All charge voltages were now 1.34V.
> 
> Is this expected or is there something wrong with my charger?



0.14 Volts is very low for NiMH cells.

You say that you had this each time you started the break in mode - was it always the same slot that showed 0.14 Volts? If so, there might be something wrong with that slot...


----------



## fourbeer

Unfortunately, I can't remember if it was the same slot.

I thought the charging voltage was strangely low. How is that determined? Does the charger do some sort of impudence check to determine the charging voltage or is it based on the capacity you enter?


----------



## Power Me Up

fourbeer said:


> Unfortunately, I can't remember if it was the same slot.



Pity... Perhaps try putting a set of cells in and try again and see what happens - at least at the start to see if any report the low voltage again, then pull them out once you've done the check.



> I thought the charging voltage was strangely low. How is that determined?


Do you remember how long it showed such a low voltage for? Even during a break-in charge, the voltage should have come up from there pretty quickly.



> Does the charger do some sort of impudence check to determine the charging voltage or is it based on the capacity you enter?


When doing a break in charge, the amount of charge it puts in is based on the cell capacity that you enter into it.

It does do an impedance check at the start of all the charge modes, but that is only used as an attempt to prevent charging of non rechargeable cells such as alkalines...


----------



## fourbeer

I did put in 1200ma, so I would not expect a low voltage. It looks like I will have to continue to experiment.

--


----------



## radellaf

Question regarding the Top Off Charge...

Is this terminated only by a 1 hour timer?

The manual says the top off is a fixed 100mA regardless of programmed capacity or charge current and I'm just wondering as regards cells (AAA) with capacities substantially smaller than 1000mAh, like my 250mAh NiCds, is this top-off going to do real damage?

If it is 1 hour overcharge at C/2.5 I would think so, unless there is another cut-off for it (voltage?) other than a 1 hour timer.

I'd also love to know why a 50 or 100mA charge current can't be selected, when the thing is fully able to deliver it. (except, of course, in Break In mode with the batteries removed before the 16 hour mark)

BTW, if you're wondering, yes, I did get 250mAh cells to run my MP3 player at work. The intent was to get a solar charger, even a cheapie, and charge them off the overhead lights. I was sure I wasn't going to get 80-100mA for NiMH, but thought I might just get 25mA. Never did buy, or build, the charger though. Normally do them in a Sony 160mA "5-6 hour" NiMH charger. But sometimes at home in the MH-9000 at 200mA.


----------



## SilverFox

Hello Radellaf,

I believe the actual top off charge runs for 2 hours now that the unit has been "improved." It has been set to terminate the charge earlier, so the top off charge was extended to make sure things ended up full charged.

This is going to be a problem for 250 mAh cells. It would probably be best to pull the cells as soon as they are done. You should run some timed tests to see how long it takes to charge a cell. You may be able to charge at 2C to drive the voltage up enough to undercharge the cell. Then the cell would be charged with the top off charge.

Keep an eye on your cell temperatures and play around a little.

I believe the C-9000 was designed around 800 - 1000 mAh AAA cells. 

Tom


----------



## radellaf

Argh, well, I think you're wholly correct there. It is annoying that the ultimate consumer charger that was supposed to be future-proof, and has all these variable charge rates.... still has fixed parameters that nail it down to cells of the capacities current at the time of its release (800-1000, 2000-2500). Worse that it has 2 sets of contacts, but uses all the same constants for AAA and AA.

The main thing it lacks, that I think causes this, is any nonvolatile memory. There are no options or settings past the one (capacity) or two (rates) entered for each cell. With configurable settings, though, would probably come a dot-matrix (128x64 ?)LCD. Those go for about $12-$15 in 1000pc qty. Probably on the order of twice what the display they're using costs. If they had to upgrade the micro, though, there's more $$.

Only way around I can think of is, instead of having us set any absolute current levels, have us set capacity and "C-rate". That would take care of both of the unfortunate fixed parameters, maximum charge or time, and top-off and trickle rates. Would mean 3 instead of 2 numbers to enter for modes like Cycle, though.

----

The 250mAh AAA charged cool-ly up to the "done" mark. Was just perceptibly above ambient at that point. I was impressed as I wasn't sure that regular NiCds are all "fast charge" capable these days. Used to be only special cells could accept more than C/5, IIRC.

It got a little warmer over the next half hour, at which point I pulled it, looked up the top off rate. Oops. Still, it was barely warm. I'm not sure, but again, if you pounded a 1980s NiCd AA with C/2.5 for an extra half hour of overcharge, I think you would have had one very unhappy cell.

I think the 160mA sony charger I have is the only one that really, safely, can handle this small cell. The 401FS, still my favorite (8xx is too big, dunno about RipVan), has a 300mA rate and a top off of 50ma, still a bit much.


----------



## sync99

Hi all,

I just purchased a MH-C9000, and I suspect the LCD in the unit may be faulty. I thought I'd check on here to see if anyone else has seen this sort of thing before.

I ran a break-in on 3 of my different old AAA's to check; one failed the impedance test but the other two ran successfully for about 30-40 hours. During this time the LCD readout was fine, crisp and clear.

Then I plugged in two more AAA's and set them to discharge first; that was when I first noticed problems with the LCD. It would show several of the words in a half-bright mode, often with the words which were half-bright not related to the current operation.
For instance, DONE started showing lit for slots 3 and 4, although I was only using slots 1 and 4 at the time. And when cycling the information several of the MAH/VOLT/CYC words were all lit at once.
When it first started a discharge operation the LCD was clear but within a minute or two I would notice certain parts of the LCD begin to flicker softly, then this would increase until many parts of it were half-bright.

Here's a few pictures to help illustrate:

Note the MODE, MIN and CYL here




See MODE, VOLT CYL and DONE here; although it's not done.




Note MAH and CYL here, and DONE on slot 3, although slot 3 was not in use.




After a while it can become impossible to see which slot is being referred to (they all appear to not have an arrow), and to see which operation it being referred to (although you can guess from the figure displayed). Plus I have noticed other oddities with the display like the decimal point appearing, and certain elements of the numbers also fading until they are invisible so that numbers aren't drawn correctly.

Has anyone seen anything like this? Does this (as I'm thinking) indicate a faulty unit?

Thanks,
Ben.


----------



## Anders

Hello sync99 and Welcome to CPF.

In my opinion your C-9000 is faulty.

Usually there is no problem with MAHA, if your C-9000 is bad, to get a new unit.
C-9000 has 3 year guarantee.

Anders


----------



## sync99

Anders said:


> Hello sync99 and Welcome to CPF.
> 
> In my opinion your C-9000 is faulty.
> 
> Usually there is no problem with MAHA, if your C-9000 is bad, to get a new unit.
> C-9000 has 3 year guarantee.
> 
> Anders



Hi Anders,

Thanks for the welcome! I've read lots of threads on torches here before but never joined until yesterday 

Thanks for the information - I've contacted MAHA and hopefully they can arrange a replacement for me. The Australian distributor I purchased the charger from (I contacted them first, before MAHA) asked that I pay for postage on the faulty item, which I'm not keen to do.

I guess I've just had bad luck, I'd read so many good reviews on this charger! :|

Cheers,
Ben.


----------



## Codeman

I agree that this looks faulty. Under some circumstances (lighting and view angle), it's possible to see everything, but that's obviously not the case here. Maha has very good support, so I'm sure they will take care of it for you.


----------



## Zot

*Maha MH-C9000 with Powerex 2700mAh*

I need some help please.

I have a bunch of new Powerex 2700mAh AA batteries. I charged 8 batteries with a C9000 in breakin mode and got mAh values 2673 and 2719...good.

I had a problem changing older powerex batteries and I got a replacement C9000 (version # ? on back sticker of both untis 0G0E01).

The new changer has yet to charge any of the 2700 powerex batteries to the lowest level reached with the first charger, 2673mAh, even after breakin mode x3. 

I have recharged the same batteries used with the first charger and the mAh values are in the 2500-2600 range. I have also charged 12 additional new Powerex 2700mAh batteries and they also consistently measure between 2500 and 2600 mAh at the end of the cycle, according to the c9000 readout.

I know that the powerex 2700 batteries say "minimum capacity 2500 mAh" but after my initial results around 2700, I am wondering if there is a problem withthe replacement c9000 charger I have.

Thanks.


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## Mr Happy

If you watch closely during charging, does the C-9000 say Done as soon as the voltage reaches 1.47 V? If so, it may be that the charge is terminating slightly early. There seems to be a high voltage safety cut-off in the C-9000 and some cells with recent formulations reach higher voltages on charge and discharge and hit this limit before the negative delta-V charge termination signal is seen.

If this happens you need to leave the cells in the charger for another two hours where they will continue to receive a lower top-off charge.

The advantage is that such early termination is kind to the cells and reduces the possibility of overcharging and overheating damage.

(Also, you hint in your post that you might be looking at the mAh readings reported at the end of a charge cycle. If you are, do bear in mind that this is only an approximate indication of the level of charge and will usually be a smaller number than you get on discharge, break-in or refresh.)


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## Zot

The mAh readings I posted were displayed at the end of the break in cycle. I ususlly leave the cells in the charger for a few hours after the display says "done." 

My main issue is that the same batteries that charged very close to 2700 mAh on one charger have never reached that same level of charge again on my replacement C9000 and neither have any of the other 12 batteries I have tried. They charge in the 2500 mAh range.





Mr Happy said:


> If you watch closely during charging, does the C-9000 say Done as soon as the voltage reaches 1.47 V? If so, it may be that the charge is terminating slightly early. There seems to be a high voltage safety cut-off in the C-9000 and some cells with recent formulations reach higher voltages on charge and discharge and hit this limit before the negative delta-V charge termination signal is seen.
> 
> If this happens you need to leave the cells in the charger for another two hours where they will continue to receive a lower top-off charge.
> 
> The advantage is that such early termination is kind to the cells and reduces the possibility of overcharging and overheating damage.
> 
> (Also, you hint in your post that you might be looking at the mAh readings reported at the end of a charge cycle. If you are, do bear in mind that this is only an approximate indication of the level of charge and will usually be a smaller number than you get on discharge, break-in or refresh.)


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## Mr Happy

Zot said:


> The mAh readings I posted were displayed at the end of the break in cycle. I ususlly leave the cells in the charger for a few hours after the display says "done."
> 
> My main issue is that the same batteries that charged very close to 2700 mAh on one charger have never reached that same level of charge again on my replacement C9000 and neither have any of the other 12 batteries I have tried. They charge in the 2500 mAh range.


Since the break-in mode supplies a constant charging current for a period of time equal to 160% of nominal capacity, I don't think there is any way the break-in mode can fail to fully charge the batteries. Therefore I suggest that one or other of your C9000's is failing to give an accurate reading on the discharge.

I don't own any Powerex 2700's myself, but maybe we can wait and see if anyone else here can report the typical capacity readings they obtain?


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## alfablue

I did a break-in charge of 4 Powerex 2700's on my MH-C9000, I got the following:

2583, 2540, 2536, 2535mah, so between 94% and 96% of the "headline" capacity.

I was satisfied with this as it was above the stated minimum of 2500mah. They were almost identical results to what I got from 4 Vapextech "2900's".


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## ridgerunner

I too, am in the process of breaking in 8 brand new Powerex 2700mAh AAs in my new MH-C9000 (version 0G0E01). I first performed a discharge, then the forming break in. The break in discharge mAh readings for the first four cells were:

2590, 2587, 2575, 2606

Thus, I got very similar (lower than expected) numbers (for the first 4 of 8 new cells - the other 4 are "currently" in break in mode). So the question is... 1.) is the MH-C9000 not filling them up to capacity? or 2.) is it not measuring the cell capacity accurately? or 3.) are these cells really just 2600mAh and not 2700mAh? or 4.) After the initial break in forming charge, the cells have simply not yet achieved their rated capacity (which will require a few more charge/discharge cycles).

I'm guessing #4, but we'll see. While cycling these new cells a few times to break them in, I think I will do a multi-cell, multi-run comparison test between the discharge capacity measured by the MH-C9000 and the discharge capacity measured by the La Crosse BC-900 (version 38,37,,33). I am curious if these two charger/analyzers will provide similar numbers... Will report back later.


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## alfablue

My suspicion is 3 - I think cells generally miss the stated capacity, would welcome other opinions.


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## Codeman

ridgerunner said:


> ...
> So the question is... 1.) is the MH-C9000 not filling them up to capacity? or 2.) is it not measuring the cell capacity accurately? or 3.) are these cells really just 2600mAh and not 2700mAh? or 4.) After the initial break in forming charge, the cells have simply not yet achieved their rated capacity (which will require a few more charge/discharge cycles).
> 
> I'm guessing #4, but we'll see. While cycling these new cells a few times to break them in, I think I will do a multi-cell, multi-run comparison test between the discharge capacity measured by the MH-C9000 and the discharge capacity measured by the La Crosse BC-900 (version 38,37,,33). I am curious if these two charger/analyzers will provide similar numbers... Will report back later.



As with most traditional NiMH cells, several cycles are needed to reach peak performance. See Maha NiMH FAQ. I wonder if Maha's nominal rating is lower than 2700, though. I couldn't find a data sheet for them. I suspect you'll see those cells all go over 2600 after a few cycles. You really should wait until they are "broken in" before you spend time on charger comparisons. Otherwise, you won't really know if any differences are due to the chargers or due to the batteries settling in.


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## TorchBoy

ridgerunner said:


> I am curious if these two charger/analyzers will provide similar numbers.


I believe the BC-900 reports slightly higher numbers, apparently because it doesn't rest the cells after charging. The MH-C9000 regime is closer to the IEC spec/standard.

And I go for #3 also. It seems very rare for non-Eneloop cells to actually achieve their rated capacity.


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## raggie33

i wonder if any of you fine cpfers would think about doing a youtube video of the features of this charger?i know i dont get a clear picture of what this thing does buy reading but a video would help me and a lot of others i think


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## raggie33

hey ok im doing the break in it went thru a charge and dishacharge now its at rest is the reading i see now the capcity of the batts?because its only like 2532mah i was hoping for at least 2700


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## Codeman

raggie33 said:


> hey ok im doing the break in it went thru a charge and dishacharge now its at rest is the reading i see now the capcity of the batts?because its only like 2532mah i was hoping for at least 2700



Hi raggie!:wave:

Yes, that is the capacity. If these are brand new cells, though, it may take a few cycles to get full capacity. You could use them a few times, then try a Refresh/Analyze and check the capacity again. If they're labelled 2700, I'd be happy with 2600.


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## raggie33

i almost want to cry. well i was doing a break in and it takes like 72 hours well i had 3 hours to go and i knocked the power adapter off the wall and the charger reset its self.lol i mean wth .any of ya do stuff this idiotoic


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## Dantor

we had a power failure in the middle of the 1st break-in cycle of my last set of AAAs (I do two break-ins), what can you do?! just contunue!


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## WDG

That's why I have the chargers on a UPS. It would certainly be a pain to kill a break-in session accidentally.

Regarding the 2700's: I have a set of these and it depends on which MH-C9000 I use as to how the capacity comes out. I have two each of 0G0C01 and 0G0D01 versions. There was clearly a firmware change made between these two groups. The "D" models rate cells more conservatively, say around 100mAh lower, and also the display backlight is a bit less bright. So my Powerex 2700's typically come out reading either around 2650-2750mAh on the "C" units, or around 2550-2650mAh on the "D" units. I'm assuming most all the later units would be pretty close to how the "D" reads the battery. Wish I'd bought all four at the same time so they'd all be the same version. That would simplify cell matching.

BTW, somewhere there's a thread that compares single vs. multiple break-in cycles, and SOME brands seem to benefit from two break-in cycles. The results were also NOT the same as simply cycling the cells.


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## Luxbright

After reading all the comments about the Maha MH-C9000 and being curious, I bought one unit with the model *0G0KA*. According to the supplier, its the latest model.

Wonder if anyone have this model.

Thanks.

Cheers,
Terry


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## ridgerunner

Luxbright said:


> After reading all the comments about the Maha MH-C9000 and being curious, I bought one unit with the model *0G0KA*. According to the supplier, its the latest model.
> 
> Wonder if anyone have this model.
> 
> Thanks.
> 
> Cheers,
> Terry


That number doesn't look quite right. I just bought one this month (Jan '08) from Thomas Distributing and its version 0G0E01.


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## Rzr800

Edit: answered my own question with more research


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## Mr Happy

Rzr800 said:


> or is the discharge number really the only _true_ measure of capacity?



Yes, though there is no single _true_ measure. For example if you discharge at different rates, or after charging in different ways, you will find slightly different discharge numbers.

The most useful thing you can do with capacity numbers is to charge up two or more cells in exactly the same way, and then discharge them in exactly the same way, and compare numbers. This will allow you to match up similar cells of similar capacities to use together in packs.


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## jusko

I have got one with no. 0G0E02. The discharged capacity of Powerex 2700 AA battery is around 23xxmah. The reading is much lower than the earlier model.

Anyone has got the same result ?


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## Mr Happy

jusko said:


> I have got one with no. 0G0E02. The discharged capacity of Powerex 2700 AA battery is around 23xxmah. The reading is much lower than the earlier model.


I have wondered about this myself, though I have not got any 2700 mAh cells to test with.

I have mentioned a few times before how the C9000 stops charging when the voltage reaches 1.47 V. This is before the -dV signal is reached, which is at about 1.51 V for many cells I have looked at, both LSD and traditional.

So I'd guess that your 2700 cells may not be fully charged by the C9000 on a standard charge cycle. To get the fullest charge into them, leave them on the charger for 2 hours after Done appears so they get the maximum top-up charge, or charge them with the break-in cycle which is on a timer and doesn't stop whatever the voltage does. Measure the discharge capacity with that and see how it compares.

Or...charge them with another charger. I have found the Duracell Power Gauge charger puts a full charge into Eneloops, but as I said, I don't have any 2700 cells to test and see how it does with those.


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## jusko

Hi, Mr. Happy, I used the cycle mode to charge the cells, so there was a two-hour rest period for topping up charge. But the final discharge capacity was around 23xxmah.:shrug:


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## Mr Happy

jusko said:


> Hi, Mr. Happy, I used the cycle mode to charge the cells, so there was a two-hour rest period for topping up charge.


I don't believe there is a top up charge in cycle mode. You would have to use the regular charging mode.

To get a true idea of your cells' maximum capacity you should run them through a break-in cycle.


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## Codeman

Even using a mode that uses top off, I don't think the reported charge numbers include top off, do they? At least, I've never seen numbers go up after "Done" appears.


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## alfablue

Codeman said:


> Even using a mode that uses top off, I don't think the reported charge numbers include top off, do they? At least, I've never seen numbers go up after "Done" appears.


Yes, that's right. Also, in Break-in mode the reported capacity is from the discharge phase.


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## Mr Happy

Codeman said:


> Even using a mode that uses top off, I don't think the reported charge numbers include top off, do they? At least, I've never seen numbers go up after "Done" appears.


It's true, the charge numbers freeze when Done appears. However the voltage readings do remain live and if you watch them you may see them increase for an hour or two after Done, especially with LSD cells. The difference in charge may be seen in the discharge readings if you do a manual discharge test after waiting for the top off to complete.


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## jusko

My Powerex 2700 cells have been used for a few times, so now break-in is necessary. I bought the 1st version of C9000 when it came out. The reading from the 1st version was around 28xxmah charging capacity and around 26xxmah discharged capacity. But the 1st version sometimes failed to cut off, the dealer was very kind and replaced it with the latest version. The charging and discharging readings are lower with this newer version no matter which mode I use.

Best Regards
jusko


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## BabyDoc

According to the specifications for the C9000, the charger should stop discharging once the voltage has gotten down to 1.00 volts. My charger, one of the newer versions, consistently ends discharge cycle when the cell reaches 0.90 volts. Is this normal? Maha service says not to worry about it, but I thought that over discharging a cell could shorten a cell's life.


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## Mr Happy

It's normal. That is 0.9 V under load though -- you will see the voltage jump back up to about 1.2 V after the discharge cycle finishes. Also when you watch the numbers, it only seems to take a matter of seconds for the voltage to go down from 1.0 to 0.9. At that point there is really no energy left in the cell.

Don't worry about it. It's reverse charging in battery sets that does the damage. Draining a single cell to 0.9 V is harmless.


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## Power Me Up

BabyDoc said:


> According to the specifications for the C9000, the charger should stop discharging once the voltage has gotten down to 1.00 volts. My charger, one of the newer versions, consistently ends discharge cycle when the cell reaches 0.90 volts. Is this normal? Maha service says not to worry about it, but I thought that over discharging a cell could shorten a cell's life.



Yes, that's quite normal - I got an older unit which stops the discharge at 1.0 volts (with the load removed) and a couple of newer units which stop the discharge at 0.9 volts whilst the cell is loaded.

I don't think that the difference is significant enough to cause a problem...


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## hydrazoon

I've just bought a c9000 version 0G0KA. It's been running 24 hours a day for the last week and I am happy with it, but I have noticed on Refresh and Analyse, that as it completes it's final charge, the time display increases by a couple of hours. For example: slot 3 completes charging, time 129 mins. "DONE" appears and time jumps to 244 mins.
What's this all about?


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## Mr Happy

I believe that when Done appears after charging, the display switches to the information measured and stored from the discharge cycle. So you see the discharge capacity and the time it took. The instructions don't specifically say this about the displayed time, but I'm guessing that's what it is.


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## Codeman

That's correct. 129 minutes is how long the final charge took, while 244 minutes is how long the discharge took. Since the purpose of R&A mode is to determine available capacity, it shows the discharge amount and discharge time once the mode is complete (DONE).


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## hydrazoon

I assume that the refresh and analyse mode is the same as the cycle mode but only cycling once.

If this is the case, wouldn't it be a good idea for later versions to have a mode where you could choose to terminate on time. You choose the charging current and the length of charge.

I'd feel a lot happier leaving the charger unattended in this mode than relying on -deltaV


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## SilverFox

Hello Hydrazoon,

Welcome to CPF.

Terminating on time isn't a good way to go either. Often, you want to just charge up your cells when they are partially used. There isn't a good way to tell what state of charge they are at, so you run the risk of overcharging them if you set your timer wrong. The way around this is to first do a complete discharge every time you charge, but that will cause your cells to wear out faster.

Also, as your cells age, the time to charge them changes.

If you want to play around with timed charges, get yourself a kitchen timer and pull the cells when your time period has ended. This will give you a back up of -dV in case you guess wrong on your time estimate.

Tom


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## sstmax

*Re: Maha MH-C9000 - reviving old cells*

Recently picked up one of these and trying to revive some Jessops (UK camera shop) brand Nimh 2300 AA's.

The instructions recommend:

1: Refresh and Analyze for 1-3 times

2: If capacity is still low, use Break-in Mode

3: If >10% improvement, repeat break-in mode for 1-3 times.

I'm onto stage 3 now in the above process, should I be using the discharge function in between the break-in cycles to avoid overcharge or just apply each charge on top of the last?

I have been discharging between break-ins as it feels like the Right Thing To Do rather than give each cell 3.2xcapacity between discharges which is essentially what running a break-in after a break-in does?

[edit: to tidy formatting]


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## Mr Happy

*Re: Maha MH-C9000 - reviving old cells*



sstmax said:


> The instructions recommend:
> 
> 1: Refresh and Analyze for 1-3 times
> 
> 2: If capacity is still low, use Break-in Mode
> 
> 3: If >10% improvement, repeat break-in mode for 1-3 times.
> 
> I'm onto stage 3 now in the above process, should I be using the discharge function in between the break-in cycles to avoid overcharge or just apply each charge on top of the last?
> 
> I have been discharging between break-ins as it feels like the Right Thing To Do rather than give each cell 3.2xcapacity between discharges which is essentially what running a break-in after a break-in does?



Hello sstmax, 

Welcome to CPF! :welcome:

There was some discussion on the topic towards the end of this thread. I don't think you will find anything more illuminating on the subject than what was previously said there.


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## sstmax

*Re: Maha MH-C9000 - reviving old cells*



Mr Happy said:


> Hello sstmax,
> 
> Welcome to CPF! :welcome:
> 
> There was some discussion on the topic towards the end of this thread. I don't think you will find anything more illuminating on the subject than what was previously said there.



Thanks Mr Happy,

Great information in that thread. I think I'll carry on discharging between cycles.

Incidentally, I also contacted Maha and was told the same thing, just apply the previous charge on top of the last.

Impressed with this charger. The cells were well down on their 2300 rating, perhaps due to the abuse the 30 min charger dished out to them.

They're still in a sorry state though, having only climbed from 959mAh to 1335 so far.


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## webfors

Hello All,

following up on this thread after almost a year. I was one of the original firmware owners that had termination issues. I got both my c9000 replaced with the 0G0B01 model and they have worked quite well, other then a few quirks with fugly old batteries. I would love to spend an hour reading all the pages to see if there were subsequent issues with this firmware, but no can do with two kids in diapers climbing and yelling at me 

I see there have been a few firmware updates since the B01. Anyone know off hand a list of changes? Thanks!


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## Mr Happy

We are told there has only been one revision to the firmware since the original release. The changing numbers on the back of the C9000 are just batch numbers and don't signify any change to the operating software.

I have never seen a list of exactly what was changed in that one revision that was made.


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## Unforgiven

Continued


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