Maha MH-C9000 SUPPORT / FAQ Thread

[wptski]

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]

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]

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]

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]

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]

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]

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?

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.