Maha MH C808M Charger

[eav2k]

Hello Eav2k,

The shut off with the RayOVac cells should act as if you removed the cell and then re-inserted it. It should start the default charge again every time it trips. It happens quickly, and that may present a problem for the charger.

If the charger doesn't reset back to normal when you unplug it, leave it unplugged for a couple of minutes, then plug it back in, you should contact Maha and ask them what is going on.

The flashing Done indicates that the charge was terminated on high voltage, rather than the normal end of charge termination. This is often seen when charging NiCd cells. However, pulling the cell should eliminate the flashing Done signal.

Let us know what you find out from Maha.

Tom

The charger has been unplugged for days, when I plugged it in all the bays went to a flashing done, this is with no cells in any bay. If I put a cell in a bay the charger does not detect it, instead it continues to flash done.

I have not contacted Maha as Thomas Distributing has agreed to replace the charger.

ed

[dekelsey61]

eak 2k or Jeff Bagley,
When you were doing the condition on your AAA batteries with your C808M charger did you put the batteries in the charger side by side or did you leave empty slots between batteries in the charger?
Dan

My third Maha MH C808M charger just died. The first lasted about two months, the second about a month, and the third about 3 months. They all died the same way, after trying to condition AAA cells. I got this charger from Thomas Distributing; who have the best customer service I have every encountered. I would be willing to try a forth C808M, but if I do get one I will not try to condition AAA cells with it. Has anyone else encountered this problem? Note that prior to these failures the chargers worked great.

[Jeff_Bagley]

dekelsey61

My first 808 failed while conditioning two aaa's. These cells were side by side, on the right hand side of the charger. The failure was indicated by a very small amount of smoke comming from the 7th from the left cell bay. After this occured, the display would ramain lit any time there was power applied to the charger wether or not any cells were present.

My second 808 failed while conditioning eight aaa's. The failure was indicated by flashing cell icons displayed for cell bays 4, 5, 6, 7, & 8 from the left. After this occured, any time a cell of any size is installed into cell bay 4, flashing cell icons are displayed for cell bays 4, 5, 6, 7, & 8 from the left wether or not any cells are installed in them.

My third 808 continues to run correctly while charging and conditioning aa's and aaa's.

[Alin10123]

dekelsey61

My first 808 failed while conditioning two aaa's. These cells were side by side, on the right hand side of the charger. The failure was indicated by a very small amount of smoke comming from the 7th from the left cell bay. After this occured, the display would ramain lit any time there was power applied to the charger wether or not any cells were present.

My second 808 failed while conditioning eight aaa's. The failure was indicated by flashing cell icons displayed for cell bays 4, 5, 6, 7, & 8 from the left. After this occured, any time a cell of any size is installed into cell bay 4, flashing cell icons are displayed for cell bays 4, 5, 6, 7, & 8 from the left wether or not any cells are installed in them.

My third 808 continues to run correctly while charging and conditioning aa's and aaa's.

hmm, maybe a bad batch of chargers? How often do you condition AAA cells in your chargers? I'm anxious to get them and will primarily be doing D and C cells but the occasional AAA cell for my LOD CE.

[eav2k]

I received my fourth charger, it is working well. Have not tried AAA cells in it yet.

[eav2k]

My fourth Maha C808M charger continues to work well. It has been used often for the past month without any problems.

I have not conditioned any AAA cells to this point, but have conditioned several sets of AA cells. The conditioning cycle will not restore the Energizer 2500 mah cells that have gone into rapid discharge mode. I am unsure of the effect conditioning mode has on other cells but those cells I have conditioned do seem to be working well.

I generally use slow charge mode when charging, but even this mode seems to be quite fast.

I recommend this charger despite having 3 of them fail on me; with the understanding that you should not try to condition cells which feature the internal disconnect that is activated when the cells begin to reach full charge.

I will try to keep the status of the charger updated.

[cam94z28]

How does the conditioning mode of this charger compare to that of the C-9000? I don't really need 8 bays as much as I need properly maintained, fast charging, and long lasting cells. If the 8 bay units will condition as nicely, I might go that route, as the C-801D is about the same price as the C-9000, and the C-800S (longer charging time) is even cheaper.

[Sub_Umbra]

How does the conditioning mode of this charger compare to that of the C-9000?....

AFAIK there is actually no way to force the Maha C808M to condition any cell of any type -- only an undocumented work-around that will fool it into a conditioning mode...if you have the time to watch it and fiddle with it.

To condition cells in the 808:

• Load cells into the bays and press 'condition'. The unit will first fully charge all cells.
• Many cells will trip out their bays and fail to condition. Keep pulling the cells that error off and put them aside, replacing them with more cells in the empty bays.
• Eventually (sometimes after a great many 'error-cells') one bay will actually go into condition mode. Then it's time to pull all other cells and replace them with the previously charged 'error-cells,' while the 808 is still in the mood.
• The 808 will not go back into charge-mode until cells in all bays are discharged so if you have more cells to condition you must keep swapping cells for discharge while the 808 is cooperating. If you fail to notice that cells in all bays have finished discharging, or if the power blinks out for half a second you will lose the condition mode and have to begin the process anew to get the 808 back into this work around conditioning mode.
• When the 808 has drained all of the cells in all of the bays (once you stop hot-swapping them) it will begin charging them. As each cell finishes charging pull it and replace it from your stack that you've already run through the machine to charge and discharge.

I think that pretty much sums up the steps to condition cells on the 808. If I've missed any steps I appologise for any omissions, while noting that the above instructions for the advertized conditioning feature are not even briefly mentioned in the instruction page that ships with the charger. I'm sure that Maha could do a better job than I of explaining it to their customers who buy the C808M if the issue was of any importance to them.

I have no experience with the condition modes of any other Maha models.

[cam94z28]

Sounds like a good enough reason to go with the c-9000. I just want to put the cells in, spend a few seconds on settings and walk away. Dont want to spend all day watching batteries. It seems the C-9000 would be more appropriate for me. Thanks for the info, I'm sure it will help out in this thread.

[SilverFox]

Hello Cam,

Welcome to CPF.

It is not quite as difficult as Sub Umbra makes it out to be. He, myself, and others are just put off by the inadequate instructions that came with this charger. It would have been nice to have this "undocumented" procedure "documented."

First, the problem.

Aged NiMh cells, and NiCd cells can end up with a higher voltage at the end of the charge. The 808 signals this termination on high voltage with a flashing "Done." So far, so good, but, the 808 will not go into conditioning mode from a flashing "Done" termination.

The solution.

The solution is to put a cell that the charge terminates with "Done" instead of a flashing "Done" in slot 1 and select the conditioning mode. The charger will charge that cell, then go into the discharge/conditioning mode. Once the charger goes into conditioning mode, you can add other cells as needed, and once other cells have been added, you can replace the cell in slot 1.

The C9000 allows you to set both the charging and discharging rates, so it is more versatile, but both chargers get the job done.

Tom

[Sub_Umbra]

Hello Cam,

Welcome to CPF.

It is not quite as difficult as Sub Umbra makes it out to be. He, myself, and others are just put off by the inadequate instructions that came with this charger. It would have been nice to have this "undocumented" procedure "documented."...

SilverFox,

As usual, you sum things up pretty well. I use the AP 2020 and the C808M and for my needs those two chargers work together very well. Contrary to my ravings I like the C808M well enough that I would buy the exact same charger again, even if it was accurately discribed in the ads. It does what it does for me so well that I have no qualms about it's functionality. It is only Maha's advertizing distortions and the lack of a comprehensive owners manual that really leave a bad taste in my mouth.

This page contains a copy of the AP 2020's manual which seems pretty complete and lacks (many of) the distortions and omissions of the one page instruction sheet that comes with the Maha C808M. AccuPower thoughtfuly provides a manual that attempts to make all of the features of their product accessable to the buyer even though the ticket price is less than 60% of the Maha. If I run across the instruction sheet that came with my Maha I'll scan it and put up a link to it.

While the feature sets of the two chargers are like apples and oranges, at least Accupower makes an effort to explain its product's capabilities to the purchaser. IMO Maha does a disservice to it's product and it's customer base by making generalized claims for this high quality product that are not accurately supported in the documentation it ships with.

I would love to be able to do a search for all of my posts about the C808M instruction sheet and edit each of them to reflect that this issue has been resolved.

[Ares]

The operators manual also states that you should not leave an empty slot when putting your cells in for charging. Maha does not know why that statement is in there… Anticipating some problems, I did a number of tests starting from right to left, filling the middle slots, and skipping every other slot. The C808M took it all in stride and performed flawlessly. It truly is an independent 8 channel charger – with no restrictions.

Here's what I found from the review linked on Maha's product page for the C808M:

Maha states in the MH-C808M manual sheet the largest capacity battery needs to be placed in the left-most side of a charger slot, followed by the next lowest capacity battery, and so on. Also, there should be no empty slots in between batteries in the charger. The reason for this advisory is because of the nature of larger capacity batteries and smaller capacity batteries being attached to the same electrical connection. If a smaller battery is placed first in line, then followed by a larger capacity battery, the larger capacity battery has the potential to draw more power from the smaller capacity battery, resulting in a false reading.

Based on this review, it seems SilverFox's tests should have worked fine, but some of the batteries may not be charged completely (or possibly overcharged?). SilverFox, can you try again and test the battery, in light of this new information? It might explain this post:

My feeling on this charger is that it doesn't seem to charge to as high a capacity as my MH-C204W, but it comes off cooler. I think I'm going to spend some time in the next few weeks to do a controlled experiment to see which of my chargers produces what charge results on my batteries.

A thing I find a little concerning is that it seems slot 3 and 4 seem to charge to a higher capacity than slot 1 and 2. I can only say this is true when charging 4 batteries at once as that is my only test scenario right now. I thought it was the batteries at first, but I swapped the positions and it happened again, so then I mixed the batteries up, and it still came out the same way. Slots 3 and 4 came out with higher capacity than slot 1 and 2. They were about 50mah apart. I have to do more testing to verify, and try out the other slots as well.

Tom, when you tested to make sure all the slots in your unit charged evenly, was that charging with all of them at the same time, or did you use one slot at a time and test the capacity after each charge? I've seen a couple of slots go from charging to complete at the exact same time which seems odd. I notice this with a few other independent cell chargers too. I wonder if the signal from one battery completing causes the other ones to trigger finished even if they're not. This needs some more investigation.

So, bcwang, try putting the batteries in left to right order by mAh capacity. So throw your 2500 mAh's in first, followed by 2,300 mAh's, 2000 mAh's and so on. See if that solves your problem.

Side story:
I've been the proud owner of the MH-C401FS for about a year. Unfortunately the darn thing got hit by lighting yesterday, evidently. It was plugged up but the LED's were off. I unplugged and plugged it back in, same thing. I also noticed that when plugging it back up, tiny sparks would fly out of the jack.

Crazy part is, I woke up this morning and tried it again.. and it works again! Although the sparks (just about 2mm long) zip out as I plug it in. Is this normal or not? I never really paid close attention before it started acting up. I know sometimes when you plug a power cord in, it can spark a little teeny bit. I'm not sure if mine is busted or not, and I'm afraid to leave it plugged up while I'm not at my house.

Basically, that's why I'm looking into this charger now. I was looking for reviews when low and behold I stumbled upon this review on CPF. Must say I love this forum!

Also, does anybody know of a Eneloop / Rayovac Hybrid type C or D battery? I was looking to use 8D's in my Maglite, but I don't want the batteries to leak all their energy before I get around to using the flashlight!

[SangYuP]

I heard the Maha C800s is exactly the same except the charge time is double. Does this mean that the 800s does trickle charge automatically after the charge is complete? So it goes into trickle once the display says "DONE"? Or does trickle charge only work when conditioning?

[SilverFox]

Hello Ares,

Welcome to CPF.

I missed your post when you posted it, so sorry for the delayed reply.

The reason to put high capacity cells toward the left of the charger has to do with the heat from the discharge circuit. If you discharge C and D cells you will notice that the right side of the charger warms up. This is where the discharge circuit is located. By keeping the higher capacity cells away from the heat, the whole charger runs cooler. Each slot is independent, so there is no advantage in charging regarding placement of the cells.

Since each slot is independent you can also skip slots, or load from right to left, or any other combination you care to use. Just keep in mind that the right side of the charger gets warm.

Lightning tends to over voltage things... I would toss your old charger and get a new one. The 808 would be an excellent choice.

The low self discharge battery manufacturers will start producing C and D cells with the new chemistry when there are as many C and D cells sold as there are AA and AAA cells. In other words, don't hold your breath...

Tom

[SilverFox]

Hello SangYuP,

Welcome to CPF.

The 8xx series of chargers all go into a very small trickle charge after charging. This happens regardless of the charge rate. The trickle charge is really a maintenance charge. While it is not recommended to leave batteries on a charger after the charge is complete, this charger would be easier on cells left in it than most other chargers.

Tom

[SangYuP]

Silverfox,

Thank you for the information! That really helps out since I am expecting mine to arrive tomorrow. So the 800s is exactly the same as the 801D except for the slower charge rate, right? Thanks again!

[john2551]

Tom,

The funny thing is in the promo pic it show the big cells on the right: http://www.thomas-distributing.com/m...8m-pic-win.htm

Someone at MAHA should have read the instructions before taking the pic!

John

[GarageBoy]

Also, fan is on the left

[SilverFox]

Hello GarageBoy,

I wasn't aware that any of the Maha 8xx chargers had fans...

Tom

[LEDAdd1ct]

Now that low self-discharge C and D cells have finally arrived, has anyone had the chance to play with either this

http://thomasdistributing.com/shop/p...d49e29ed2e9968

or this

http://thomasdistributing.com/shop/p...789f59dd2b604d

in the C808M?

I am thinking of picking up a bunch of the LSD D size and a pair of the C to use, and was wondering how they do/how they do in this charger.


LEDAdd1ct

[Anders]

Hello LEDAdd1ct.

A good choise, they should perform as good as C808M perform on AA and AAA LSD cells, flawless

Anders

[ChuckD]

What a great discussion! This is my first post here and I'm not sure this is the correct place for this question so I'll start a new thread if desired. My question is about the C808M tho.

I have around 30 of those solar lights you stick in the ground to illuminate walkways, etc. I did some research on them and found the Westinghouse Europas to be the best, and they are great. Each has two LEDS and two rechargeable AA NiCds. The batteries are labeled IDC brand 900 mAh.

I've been using Powerex NiMHs for my digital camera needs for several years now, 2000 and 2100, and I decided to try them in the solar lights as I retired them from photo use. They work fine.

My question is as follows. Now I have a boatload of rechargeable AA's of various ages and capacities. I'm finding my solar lights are showing uneven charging and suspect many of these well used batteries are failing.
But since the lights each take two batteries, I can't be sure which is the weak one. So, can this charger be used as an indicator of battery health? Obviously if a battery won't charge, that's a clue right there. But is there something about how the charger reacts to a given battery that I can use to weed out the depleted ones?

Also, given that these batteries are charged on a solar charger during the day (possibly not to capacity) and depleted overnight, what's the best strategy for prolonging their life? Would they benefit from periodic conditioning?

Thanks all for your participation, it's been very 'enlightening' (sorry!).

ChuckD

[Sub_Umbra]

Now that low self-discharge C and D cells have finally arrived, has anyone had the chance to play with either this

http://thomasdistributing.com/shop/p...d49e29ed2e9968

or this

http://thomasdistributing.com/shop/p...789f59dd2b604d

in the C808M?

Thanks much for the links. I've been out of touch for a couple months and I've been hoping someone would come out with lsd Cs and Ds for some time now. This is great news to me.

Thanks again for the links.

I love this place.

[Canuke]

Ditto here. Somebody had said in passing elsewhere that C and D LSD's were out, and I was just about to post asking where they were.

Thanks LEDAdd1ct for the links!

Now I just need to figure out what application I need these for, instead of AA Eneloops in adapters...

[SilverFox]

Hello ChuckD,

Welcome to CPF.

While the 808M is a great charger, it lacks analytical capabilities.

If you are in the market for another charger... check out the C-9000. It has the analytical capabilities you are looking for.

You may be able to check voltages and weed out some of your cells. Also, you can measure the voltage of the cell under a load. You can use a resistor as a load and sort your batteries by voltage under load after they are fully charged.

The next step is to check the cells for matching capacity. Your lights use 2 cells in series. If one cell has less capacity than the other, the light will prematurely dim. If you get up early in the morning, you can pull cells from the lights and immediately measure their voltages. If one cell in a set is a lot lower in voltage, or has gone to negative voltage, it was the one that had lower capacity. It takes some time to go through your batteries this way, but it usually works. You can mark the low voltage cells and begin using them together in sets. Or you can set aside the low voltage cells and use the stronger cells.

You can also do this testing with a flashlight.

Tom

[ChuckD]

Thanks for that SF, wasn't aware of this analyzer. I was hoping there would be something about a battery's behavior in the C808 that would be a give-away to it's health.

Thanks again.

C.

[Ares]

Hello Ares,

Welcome to CPF.

I missed your post when you posted it, so sorry for the delayed reply.

The reason to put high capacity cells toward the left of the charger has to do with the heat from the discharge circuit. If you discharge C and D cells you will notice that the right side of the charger warms up. This is where the discharge circuit is located. By keeping the higher capacity cells away from the heat, the whole charger runs cooler. Each slot is independent, so there is no advantage in charging regarding placement of the cells.

Since each slot is independent you can also skip slots, or load from right to left, or any other combination you care to use. Just keep in mind that the right side of the charger gets warm.

Lightning tends to over voltage things... I would toss your old charger and get a new one. The 808 would be an excellent choice.

The low self discharge battery manufacturers will start producing C and D cells with the new chemistry when there are as many C and D cells sold as there are AA and AAA cells. In other words, don't hold your breath...

Tom

Thanks for the welcome! It seems I missed your post as well, though. I had subscribed to this thread but never received any notification - although other threads notify just fine. But anyway...

Thanks for the info about the heat and battery placement. That makes a lot more sense. The way other sites / people had been explaining it, it sounded like it didn't have independent slots. I've read several places that you should not skip slots, etc. Slightly confusing. I emailed Maha about this, and my charger that was acting screwy. The guy from Maha frankly told me he had no idea why their website stated to do that, and to disregard it haha. I'd post the email, but it's been so long that I've deleted it.

Seems I didn't have to hold my breath for too long for those low self-discharge D batteries, eh? Haha. Thing is, I still have my old charger actually. The Maha guy said that short little "spark" when I first plug it in, is normal. And that if you plug the charger in with the batteries already inside, sometimes it will not do anything at all (e.g. appear to be broken due to a lightning strike, I suppose). So my charger is just fine. Was just a fluke, evidently. I'm still considering this other charger though - but I'm thinking some AA to D battery converters would be just as good, and way less expensive. Those Powerex D batteries are expensive! Thing is, I can't figure out where to buy any 3 or 4 AA to 1 D converters (I'd want them as parallel, not in a series). I found where Warren was selling a few on here, but he doesn't seem to be around anymore...

Any clue where to get those? Perhaps you could PM me, as to not get this thread too horribly off-topic

Thanks!

[SilverFox]

Hello Ares,

You will have to do some searching on CPF. I believe there are some AA to D adapters available, or in the process of being made.

It would be interesting to see how well AA cells stay in balance if they are paralleled in a D holder and charged in the 808...

Tom

[john2551]

Ares,

Eastgear & aventrade used to sell 4AA to D parallel adapters.

[Ares]

Yeah, they are both sold out. Believe me, I did my homework. I scoured this site like crazy before posting, but I can't find any available.

http://www.eastgear.com/shop/index.php?cPath=29_50
http://www.aventrade.com/baad.html

I see where SilverFox mentioned someone might be in the process of making them here - but after looking, I have no idea whom. Except that Warren guy that hasn't posted in a month.