Maha MH-C9000 SUPPORT / FAQ - continuation

[teacher]

Thanks for the feedback guys!

After much homework, the Maha Powerex Wizard One MH C9000 is what I am going with.

Good for you!!! :thumbsup: :goodjob:

I have feeling I will not be disappointed.

You won't....

 

[roadwarrior]

Pulled the trigger today on the Maha Powerex Wizard One MH C9000!

Looking forward to asking many more questions once I get it and realize I have no idea what I am doing.....

Thanks for all the feedback, I could not have made such an informed decision if it were not for the many folks on here who shared with me their time and knowledge . :thanks:

 

[roadwarrior]

So, I ran a refresh/analyze on a set of 2300mAh Energizers that have been in constant use for 2 months, but recharged with a dumb charger up until now.

These are the mAh numbers I got at the end:

Slot 1-2222mAh
Slot 2-2159mAh
Slot 3-2212mAh
Slot 4-2172mAh

Thoughts?

Is that good or bad? Do I need to do something else to get up to their rated capacity? Or is that the best I can expect?

 

[MidnightDistortions]

Try a break-in though you may need to cycle them first to get rid of any overcharge. Those capacities are not bad either way.

 

[roadwarrior]

Cycle as in.....run a discharge first....then run a break in....correct?

 

[MidnightDistortions]

Cycle as in.....run a discharge first....then run a break in....correct?

There's a cycle function that will charge, discharge as many times as you want. I would do the cycle 3x and then if needed run a discharge before doing the break-in.

 

[roadwarrior]

There's a cycle function that will charge, discharge as many times as you want. I would do the cycle 3x and then if needed run a discharge before doing the break-in.

I try that. Thanks!

 

[BATTY]

So after reading this entire thread, there is no top off charge after the break in mode.

What modes do top off and what would be the best way to top off batteries that have just finished the BI mode?

Seems like a bit of an oversight to omit this on the BI mode, unless it would skew the final capacity numbers?

 

[Rosoku Chikara]

So after reading this entire thread, there is no top off charge after the break in mode.

What modes do top off and what would be the best way to top off batteries that have just finished the BI mode?

Seems like a bit of an oversight to omit this on the BI mode, unless it would skew the final capacity numbers?

I believe you can assume that your cells are completely "topped off" after the Break-In mode. As I recall, it charges at 0.1 C (or 10% of cell capacity) for 16 hours. I believe in most situations, your cell would be fully charged under these conditions in about 10 hours (!0% x 10 = 100%). So, I am fairly certainly that after 16 hours, the cells will be up to their maximum capacity.

In any case, I usually want to know the cell capacity as accurately as possible, after running an Break-In. So, I usually run a Discharge, and then a Refresh & Analyze after every Break-in. But, if you have know interest in knowing the accurate cell capacity, I am pretty certain you can use cells that have just been "Broken In" without any fear that they might not be fully charged. (PS: In my experience, the capacity shown after a Break-In, or any other mode -- except Analyze" -- for that matter, is not very accurate; they are only approximate.)

 

[Yamabushi]

As I recall, it charges at 0.1 C (or 10% of cell capacity) for 16 hours. I believe in most situations, your cell would be fully charged under these conditions in about 10 hours (!0% x 10 = 100%).

Although charge efficiency of NiMH varies with the state of charge, the overall efficiency is approx. 66% at 0.1C so you need approx. 15 hours.

 

[Rosoku Chikara]

Although charge efficiency of NiMH varies with the state of charge, the overall efficiency is approx. 66% at 0.1C so you need approx. 15 hours.

Thanks for explaining this! I finally understand why it charges for 16 hours. (This may be explained somewhere else in this thread, or on this forum... I cant say that I recall ever reading it before. If I ever did it was a long time ago.)

In any case, what you say makes great sense to me now. So, 16 hours should deliver 100% charge, plus a little extra for good measure. Right?

 

[ComputerTime]

Hi,

I did not manage to read through the whole thread; too many posts.

Anyway, I have been using this Maha charger since it is launched, did not explore much into this C9000 charger.

I just realised that that I have some Imedions and 1 Eneloop (Sanyo) battery is only around one-third of the capacity. I always do a "refresh/analyse" when charging the batteries. These batteries capacity are reduced because I seldom charge them.

Is it possible to restore the capacity by doing some cycling? How many cycles are required? For charging, the rate that I will use is 700mAH and 300mAh for discharging, since they are all slow discharging battery.

In addition, I have some Imedions that the charger reflects as "HIGH". Is there anyway to revive the battery, or I will have to make way for new battery?

Regards.

 

[SilverFox]

Hello ComputerTime,

Welcome to CPF.

Cycling through charge/discharge can sometimes help revive a cell, but at other times it doesn't do anything at all. You take your chances and live with your results.

HIGH cells mean that the internal resistance of the cell is high. High resistance means that the cell will heat up during charging, especially at higher current charging. To avoid high cell temperature the charger flags high internal resistance as HIGH and refuses to charge them.

High internal resistance also means that the cell will drop in voltage under load and it's performance will be sub par. I recommend recycling the cells and starting with new cells, but others try to find low current draw applications and also find a stupid charger that doesn't check for the resistance of the cells prior to charging and also doesn't have the capability of charging at higher rates.

If you "love" your particular cells and have an attraction to them you can try a deep discharge followed by a Break-In function. Discharge the cells in the C-9000 at 100mA, then put the cell into a single cell light that has a low current draw. Turn the light on and let it run until it shuts off. Then put the cell in for a Break-In. After the Break-In do a discharge and see if the capacity is within 80% of the cells initial capacity. If it is, charge it back up and use it. If it is not, recycle it and move on knowing that you tried.

Tom

 

[ComputerTime]

Thanks Tom.

I tried once to use the stupid charger to charge for 2 hours on my "High" Imedion, after that, go through the "Refresh/Analyse" option. It only restored around 10% of the capacity. With the "high" battery, you will not be able to charge/discharge the battery. The C9000 do not allow you to proceed further.

I guess time for me to get new eneloop batteries. :twothumbs

 

[ChrisGarrett]

Thanks Tom.

I tried once to use the stupid charger to charge for 2 hours on my "High" Imedion, after that, go through the "Refresh/Analyse" option. It only restored around 10% of the capacity. With the "high" battery, you will not be able to charge/discharge the battery. The C9000 do not allow you to proceed further.

I guess time for me to get new eneloop batteries. :twothumbs

I've been able to trick my Maha C9000 into charging some Sanyo 2700 HSDs that are reading HIGH...like 2.6x volts high.

You just have to insert them, hit the 1A (or 2A) charge rate and start, HIGH will show, remove battery, reinsert battery, rinse and repeat, until the resistance drops to about 2.11v, where my C9000 will begin charging. It was taking me 5-6 times to get them to charge, before I finally ditched them and sent them to the recycling bag.

But a HIGH battery can sometimes be tricked into charging again. That or just use a dumb charger. Eventually, they'll have little left.

Chris

 

[MidnightDistortions]

Some of my high resistance cells gets charged in the Last Crosse charger, really old ones gets charged in the dumb chargers. I notice most older cells will work in this LED string lights. But I won't bother with cells that will discharge within a day or less. Thats generally when you know all the cycles in the cell has been exhausted.

 

[kreisl]

Did NE1 say something about broken pins, cracked posts, broken screw posts or alike? Oh no, that was in the other charger thread, early production units ; regarding the screw posts, there it was a matter of Chinese plastic material quality, not of the construction. The screw posts had the standard engineering construction and had thick wall thickness, even though the construction was revised in June '16 to sport even thicker wall thickness.

So I was curious how Maha's plastic material quality would hold up in comparison or the construction for that matter. Since there are no moving parts and no mechanical strain, nothing could break or crack, right? Or at least, one would not feel the need or motivation to open up the MH-C9000 for the sake of opening up.

I own a neat collection of c9k's sku244908, they are reliable for testing Eneloops (…) and recognize fully charged batteries super fast. I went ahead and first checked my reference unit from 2014. The disassembly (and reassembly) is straight-forward, one can find few youtube clips (in poor video quality) on this topic. The upper plastic case half has a total of 7 screw posts: 4 for the external screws plus 3 for the internal screws.

I was surprised that 6 out of the 7 screw posts, i.e. 85% of them, were damaged. Cracked, but still in place and serving.

After examination it was clear why they had cracks. Two reasons.
Reason no.1: thin wall thickness.
Reason no.2: non-centric borings by the drill or tap.

I don't know if the borings were made by drilling machines or tapping machines; probably they come to existence by the roboter-automated screwing of the self-tapping screws. Either way, the borings were non-centric and due to the thin wall thickness this leads to the cracked threaded walls of the plastic posts.

Yes the charger construction as a whole feels sturdy and well-made, I must agree. The tolerances between the physicals parts (upper case half, bottom calf half, PCB, display, etc) are professionally tight, everything clicks in place with no air gaps or play. And if the borings were 100% centric, i could marvel at the precision of manufacturing and the then amazing build quality. But after my critical examination and fair assessment i feel disheartened: the plastic material quality is cheap after all and, in fact, inferior to other ABS plastic chargers i own, the wall thicknesses are thin (at the 7 screw posts and also in the battery slots, i.e. wherever the 'concept of wall thickness' becomes apparent), and, as documented in this post, the non-centric tappings lead to cracked walls.
:sigh:

All 7 photos are in 1088p, feel free to view in full resolution:

I've checked other years c9k units from my collection (i entered the flashlight scene in 2011) and all of them had 6/7, with varying degrees of crack severity. And that same number is exactly why i feel disheartened. Maybe your pre-2011 unit has only 3/7 cracked (walls in the) posts but i am herewith claiming (for good reasons kept to myself) that nobody will have 0/7, until i am proven wrong. The above 7 photos are taken with my phone, i've uploaded the pics to abloadDOTde which is FREE for anybody, i.e. anybody with a phone and internet browser could easily share proof that he has 0/7 or only 3/7.

I am guessing that the Maha production/QC/QA dpt must have been fine with this number, since the fit'n finish tolerances are so tight and cracked posts don't compromise the function and feel of the product, and "nobody" would open the charger for modding or repairs (since there are no moving parts) and opening the charger would invalidate the warranty anyway. Or "nobody" would care when seeing this number.

I must admit that broken posts on the other charger were an issue and that cracked posts on this charger are not an issue. Then what's the point of this post of mine? Nothing but documentation and sharing information, knowledge. You were probably not aware, didn't know, or were wondering. At the end of the week I still love my fleet of c9k's but this piece of knowledge has opened my eyes and raised my awareness.

The product is not built as well as i had pictured it from its appearance/feel.
kreisl aka "nobody". Disheartened. Desilusionado. :ironic:

 

[TinderBox (UK)]

The C9000 design is over 10 years old, Apart from the channels dying usually after many years of good service, I have not see any other hardware problems, If the screw posts were cracking that must have been the limit as i have not found any loose plastic rattling around any of my charger`s

Self Tapping plastic pillars have always been a cheap was of getting the job done and i have seen many device with posts split or broken off completely, machined brass inserts is the quality way to go but it`s all down to money in the end.

John.

 

[kpatz]

I just picked up my 2nd MH-C9000 today. I figure, with Refresh/Analyze taking ~10 hours and Break-in taking nearly 40, I can do twice as many batteries per day/week with 2.

This is interesting though: the first one I got (from an Amazon seller), has a serial code of 0Q0GA. Based on an earlier post I found indicating that "K" in the 2nd position signified a 2011 manufacture date, that would make this unit made in 2017, so pretty much a brand-new one. The 2nd one, which I got today, I picked up at a local Batteries+Bulbs store, since I didn't want to wait for shipping, has a serial code of 0J0CA. 2010!? It sat on a shelf or a warehouse for 7-8 years? Wow... it seems to work fine though. The LCD on the 2nd (older) unit is slightly darker and doesn't have as much of a blue cast to the backlight. I don't know if any other notable differences there are, in firmware or whatever, between 2011 and 2017. The guy at the store also said the MH-C9000 was discontinued, though I don't seem to see this indicated anywhere on the internet... maybe he meant the store was going to stop carrying them.

Thoughts?

 

[SweD]

I just picked up my 2nd MH-C9000 today. I figure, with Refresh/Analyze taking ~10 hours and Break-in taking nearly 40, I can do twice as many batteries per day/week with 2.

This is interesting though: the first one I got (from an Amazon seller), has a serial code of 0Q0GA. Based on an earlier post I found indicating that "K" in the 2nd position signified a 2011 manufacture date, that would make this unit made in 2017, so pretty much a brand-new one. The 2nd one, which I got today, I picked up at a local Batteries+Bulbs store, since I didn't want to wait for shipping, has a serial code of 0J0CA. 2010!? It sat on a shelf or a warehouse for 7-8 years? Wow... it seems to work fine though. The LCD on the 2nd (older) unit is slightly darker and doesn't have as much of a blue cast to the backlight. I don't know if any other notable differences there are, in firmware or whatever, between 2011 and 2017. The guy at the store also said the MH-C9000 was discontinued, though I don't seem to see this indicated anywhere on the internet... maybe he meant the store was going to stop carrying them.

Thoughts?

I've had my C9000 since I don't know when, it's a 0H0BB version, and it's still working great, and as far as I know at least, nothing much has happened with it since the initial problems were ironed out.
As for it being discontinued, that seems unlikely, unless Maha has something new up their sleeves, at least it's readily available on the Maha-webshop page, as of now. Only thing they don't have and haven't had for some time is the MH-C808M, listing it as "out of stock", which is a tad strange with Maha being the manufacturer.