Maha MH-C9000 SUPPORT / FAQ - continuation

[hagbard]

Got another question. If the brake-in is interpreted by a power outrage, what then? I got about 31 hours into it, and the power went out and it switched to "Charge". Do I start the brake-in again or just go ahead and charge them?

 

[45/70]

hagbard, that far along, the C9000 was interupted during the second, and final charge. I would just charge them up and use them. The big drawback is that you don't probably know what the final capacity was, unless you happened to notice. To get that, you'd have to start all over again.

Dave

 

[hagbard]

hagbard, that far along, the C9000 was interupted during the second, and final charge. I would just charge them up and use them. The big drawback is that you don't probably know what the final capacity was, unless you happened to notice. To get that, you'd have to start all over again.

Dave

Okay, I guess this brings me to yet another question, what is the "charge rate"? Haven't charged any batteries yet. Is it the rating on the battery or the "discharge rate"? They're eneloops rated at 2000mAh.

 

[fishinfool]

Okay, I guess this brings me to yet another question, what is the "charge rate"? Haven't charged any batteries yet. Is it the rating on the battery or the "discharge rate"? They're eneloops rated at 2000mAh.

I normally go with a charge rate of 500ma or 1000ma depending on how quickly I need the batteries.

 

[hagbard]

I normally go with a charge rate of 500ma or 1000ma depending on how quickly I need the batteries.

Okay, so the charge rate doesn't really relate to the capacity of the battery, its how much juice is being delivered at a time. I'll still get the full charge, correct?

 

[fishinfool]

Okay, so the charge rate doesn't really relate to the capacity of the battery, its how much juice is being delivered at a time. I'll still get the full charge, correct?

It does, it just takes longer to charge when at lower rates.

 

[TakeTheActive]

Okay, I guess this brings me to yet another question, what is the "charge rate"? Haven't charged any batteries yet. Is it the rating on the battery or the "discharge rate"? They're eneloops rated at 2000mAh.

Both Anders and pae77 already answered that question.

What part of their answers didn't you understand?

Are you interested in investing some personal time and learning about the theory and proper maintenance for your cells?

(No 'touting' this time!)

Hello Hagbard.

Welcome to CPF:wave:

1. Set it at the rated capacity, 2000 mA with your cells.

2. Thats normal.

3.When you are not in a hurry, set the charge rate at somewhere between 0,5-1,0 C. With your type of cells (2000mAh) I would have choosen 0,5-0,7 C which is with your cells 1A- 1,4A per cell.

If you dont touch any buttoms, the charger charge your cells with 1A which is ok with your cells.

Anders

Originally Posted by hagbard View Post
Just bought this charger, and I'm a total newbie and find the instructions a bit confusing, so I'll blast off a few questions:

1. When using Burn-in, it asks for "Set Battery Capacity". Would I be right in assuming I set it to the stated capacity on the battery, which if 2000mAh I'd set it to 2000mAh. Asked in another forum and they said set it to 1000mAh, which is the discharge rate?
You set it to the actual stated capacity on the battery label, assuming it is more or less accurate, which in the case of quality batteries is usually the case. The value is used by the charger to calculate the rate at which it is going to charge during the break-in cycle.

2. When completed my batteries have reported voltage of 1.46v not 1.2v, is that normal? It's normal for the batteries to come off the charger a little "hot" (as in high voltage, not temperature). Once a load is applied, the voltage will sag to expected levels.

3. When using "Charge" do I manually set the "CHG Rate" to the rate printed on the battery, use the settings it sets up automatically, or the "discharge rate"? The general consensus, I believe is that it is optimal to charge at about 1/2 C or 1/2 the actual capacity of the battery. So in the case of a 2,000 mah Eneloop, you would charge at 1,000 ma which is the default the C9000 is set up to charge at if you don't enter anything. If you are in a hurry, it's acceptable to charge at a higher rate, but it's best for the battery to charge at .5 C. Too low a rate and you risk the charger missing termination. Too high a rate and you risk damaging the battery or shortening its useful life. So .5 to 1C is the usual accepted appropriate range, for NiMH and NiCad, imo.

thanks.

The above is just my opinion based on the reading I have done here and elsewhere.

 

[hagbard]

It does, it just takes longer to charge when at lower rates.

Thanks, that was helpful .

 

[TakeTheActive]

Thanks, that was helpful .

(I read your ORIGINAL, unedited post too.)

AFAICT, you're a Newbie (just joined CPF, low post count), you're asking basic questions, 2 members gave you detailed answers and you repeated one of your original questions. IMHO, you sound confused and I'm offering to help clear up some of that confusion.

Now, you can continue asking 'Asked-and-Answered' questions, and getting sometimes complete / sometimes incomplete answers. Or, you can invest some of your personal time and read some basic theory - information originally posted by many CPF Gurus.

I'm not looking to insult anyone - I'm just pointing out that reading FAQs are more efficient than posting a Frequently Asked Question and waiting for a random complete / incomplete / right / wrong answer.

 

[hagbard]

I just want to charge my batteries with a minimum of hassle, not be be an expert. I just tired doing the Charge mode, and put in three batteries, every time I do, it sends me back to Mode. Its not accepting more than one battery.

Here's what I'm doing:

1. I put an AAA in slot one, Select Charge mode, press Enter, select 400mAh, press Enter.
2. I then put an AAA in slot two, Select Charge mode, press Enter, select 400mAh, press Enter.

--> it now goes back to slot one and asks me to select the Mode again?! If I put all the batteries in, go from slot to slot doing the above, it looses all the settings. I think its not working.

 

[pae77]

I just want to charge my batteries with a minimum of hassle, not be be an expert. I just tired doing the Charge mode, and put in three batteries, every time I do, it sends me back to Mode. Its not accepting more than one battery.

Then just insert them in the C9000, give it about 4 or 5 hours and your batteries will be charged. Then simply remove your batteries and use them. Despite your statement above, this will work unless your C9000 is defective. But I believe your C9000 is fine and you are simply misinterpreting how it works and what the display is doing and the timings involved.

Simply don't pay any attention to the the confusing (to you) display as it requires some mental effort and knowledge to understand what it is doing and telling you. An effort that you obviously are not interested in making. Just trust that the C9000 will charge your AA and AAA batteries more or less properly with no intervention or input needed from you beyond simply properly inserting the batteries into the charger. Everything else will be taken care of automatically and the charger will use its default charge rate of 1000 ma for AA batteries, and whatever the default is for AAA batteries (probably 400 ma) and that will be fine for most NiMH batteries you are likely to be using.

 

[tandem]

whatever the default is for AAA batteries (probably 400 ma)

Nope. 1000 mAh default regardless of battery type for the C9000.

Some reading or intuition is required if you want to get the most out of the C9000 and devices like it. If one doesn't want to learn how to use the device to the optimum, just pretend it has no display, pop your cells in and walk away. They'll get charged.

 

[hagbard]

pae77 Actually, it won't let me do that. When it asks for Mode again, it brings up 1000mAh then goes back and asks for Mode again. Endless loop.

I think I might have found the problem. Eric at Maha said it doesn't handle older batteries well. I tried four new ones and it works. I then tried the older ones and when I left out one of the batteries it started working, seems to be a bad battery screwing things up. Thought this charger issued a warning (HIGH) if a battery were defective?

I need to get batteries going and have to jump in...I'm sure the more I use it, the more I'll pick up. I just don't have the time to study the fine art of battery maintenance all in one go. I have a handicapped five year old who depends on her batteries.

 

[bbb74]

You might not be fully inserting the aaa bettery into the c9000. Sometimes with the aa's it seems like its in, but its not really. Usually the top isn't quite in, give the top of the battery a good solid push, you might find it clicks in further.

 

[Mr Happy]

Here's what I'm doing:

1. I put an AAA in slot one, Select Charge mode, press Enter, select 400mAh, press Enter.
2. I then put an AAA in slot two, Select Charge mode, press Enter, select 400mAh, press Enter.

--> it now goes back to slot one and asks me to select the Mode again?! If I put all the batteries in, go from slot to slot doing the above, it looses all the settings. I think its not working.

What Eric told you is correct, but it might not be the only problem.

If the C9000 thinks you have inserted an alkaline battery it will simply refuse to charge it and will keep going back to the mode display again. Very old and bad rechargeable batteries can behave like this. If they do, you really need to recycle them and replace them with new ones.

However: this is not the only possible problem. Some AAA batteries have a wrapping that curves around the end of the negative end of the battery, and this can prevent the C9000 making proper electrical contact. (Only happens with AAA cells, not AA cells.) This problem has happened to me before now. If your batteries look like this, you should carefully trim back the wrapping with a sharp pair of scissors to expose more metal. Then try again. You will notice that many new AAA cells have a wrapping that does not curve around the negative end and these should be good to go from the outset.

 

[45/70]

Okay, I guess this brings me to yet another question, what is the "charge rate"? Haven't charged any batteries yet. Is it the rating on the battery or the "discharge rate"? They're eneloops rated at 2000mAh.

I use a charge rate of 0.5C for most of my cells, unless I need them charged in a hurry, then I'll go as high as 1C. "C" = the capacity of the cell in mAh, but is expressed in mA, as this is charge current, not capacity. For example, if you have a 1000mAh cell, 0.5C = 500 mA current rate and a 1C rate would be 1000mA. So a 0.5C charge rate for a 2000mAh eneloop AA would be 1000mA which, as already mentioned, is the default rate of the C9000, ie. you don't need to input data, unless you want a different charge rate.

As for the problem you are having with your cells not being recognized by the C9000, it sounds indeed, like you may have some old, or damaged cells suffering from high internal resistance, as Eric said. It could be, as Mr Happy suggested, that the bottoms of the cells are not making proper contact. If I place the negative end of the cell in first, I've had little problems with this. There are apparently, two or three versions of negative contacts used in the C9000, yours may be different than mine.

I would avoid trimming the shrink wrap, if possible, if you run into this problem in the future, as I've had cells short out that didn't have the wrap go around the negative end of the cell a bit. This has only ever happened with Sanyo 900 and 1000's which don't have the wraparound shrink wrap, when used in 3 AAA lights that use a battery carrier. The carrier can shift slightly in the light body and short the end of one of the cells against the body, if the wrap does not go around the end of the cells.

Sounds like you have things under control, now. Enjoy your C9000, it's a great charger/analyzer.

Dave

 

[TakeTheActive]

It's *REALLY* Up to You...

I just want to charge my batteries with a minimum of hassle, not be be an expert. I just tired doing the Charge mode, and put in three batteries, every time I do, it sends me back to Mode...

Basic, NO FRILLS / NON-TECHNICAL answer:

When the Maha MH-C9000 'blinks' and goes back to MODE, it believes that the cell has an EXTREMELY high Internal Resistance and cannot be recharged. RECYCLE (aka properly TRASH) it and move on.​

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More Technical / Informative answer:

CLICK on my Sig Line LINK and read about "Maha MH-C9000 Impedance Check Voltage".​

__________________________________________________​

Then just insert them in the C9000, give it about 4 or 5 hours and your batteries will be charged...

This is not true. If the MH-C9000 'blinks' and continuously returns to MODE, it will *NEVER*, AFAICT, attempt to charge that cell.

Well, to be perfectly honest, the TEST voltage that the MH-C9000 applies to the cell each time it 'recycles / Tests it', *WILL* impart some MINOR charge to the 'soon-to-be-departed', 'worn out / neglected / abused' cell. But, in the BIG PICTURE, does it really matter? :thinking:
(Oops! I'm again going off on one of my EXCESSIVE FORMATTING tangents! )

...Just trust that the C9000 will charge your AA and AAA batteries more or less properly with no intervention or input needed from you beyond simply properly inserting the batteries into the charger. Everything else will be taken care of automatically and the charger will use its default charge rate of 1000 ma for AA batteries, and whatever the default is for AAA batteries (probably 400 ma) and that will be fine for most NiMH batteries you are likely to be using.

This is also not true. The MH-C9000 will default to a Charge Rate of 1000mA for *ANY* cell inserted into *ANY* channel that the USER has not changed / programmed before the timeout period expires. IMHO, based on the knowledge I've gained from reading the CPF 'Batteries Included' Archives, 1000mA (aka 1.25C) is TOO HIGH of a Charge Rate for 800mAH AAA cells.

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Disclaimer: I've NEVER experienced the MODE response from not properly inserting an AAA cell. I *HAVE* experienced it when attempting to charge a *CRAP* cell (AA or AAA).

Note: I may be a BLUNT, STUBBORN, "OLD FART", but, if you're willing to invest some personal effort, I'm 'ready, willing and able' to share the knowledge I've acquired from my hundreds of hours of reading the CPF 'Batteries Included' Archives. :wave:

(Note 2: To the 'regular readers' of 'Batteries Included', please note that I've acknowledged your post(s) regarding my EXCESSIVE use of FORMATTING and, IMHO, have appropriately cut back (ESPECIALLY in the recent Hybrid thread with the medical graduate). Currently, I've been up ~33 hours, trying once again to cure my insomnia and restore my circadian rhythm to the norm of ASLEEP when it's dark, AWAKE when it's light )​

 

[pae77]

Thanks for the corrections and I'm sorry for any incorrect information I posted.

It's been a while since I charged any AAA's in my C9000 so I forgot about the default charge rate on those. At least I did indicate I wasn't certain what the C9000's default charge rate was for AAAs.

However, 1.25 C while, obviously, not an ideal charge rate, and not one I personally would use, is not going to destroy AAA's in a hurry. For someone who has indicated they don't want to be bothered learning about the finer points of charging with the C9000, I still think it is reasonable under those circumstances to tell them to just insert the cells and let the charger charge at the default rate, especially after the proper charge rate range (.5 to 1 C) was explained several times first, and apparently was not sinking in.

 

[tandem]

Some AAA batteries have a wrapping that curves around the end of the negative end of the battery, and this can prevent the C9000 making proper electrical contact. (Only happens with AAA cells, not AA cells.)

Interesting, I'd not noted that before but in AAA size I only have Imedions, Eneloops and "Duraloops".

Of these three only Powerex/MAHA's own Imedion 800 AAA cells have a little (miniscule) amount of wrapping extension beyond the negative end - must be less than a millimetre - and it barely covers the radius of the outside bottom edge of the cell. I've not noted any problems from these, but certainly can remember not inserting AAA cells quite right the first time 'round.

 

[InHisName]

Re: It's *REALLY* Up to You...

Basic, NO FRILLS / NON-TECHNICAL answer:

When the
. . . . . .
More Technical / Informative answer:

CLICK
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Its good to see this two stage type of answer. The direct 'bottom-line' quick answer. AND the link to the very detailed full explanation.

For some with so little time to spare the sparse answer is good enough. Having a multi colored answer on a formatted platter can still be too time consuming. Now people can do both or just the fast answer as their time fits.

Keep on doing the dual-answer style with formatting.
hagbard: those are likely to be junk cells and c9000 wont charge them. If had tired to charge them they would get very warm or hot! Since you're just getting started you may not have enough eneloops / new cells, so you may need to use these junkers until more replacements are purchased according to your family budget. The ONLY use for mode 'cyclers' is remotes or clocks. If you have a charger that charges AAA & AA in 16 hours, then they can be charged slow enough to not get too hot.

If an eneloop runs down one of your clocks in 4 months, then a junker might last a month or two at most. A cell that registers HIGH might last 2 or maybe even 3 months in the same clock.
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