Breaking-in AAA eneloops.

Cheers everyone.
First of all I would like to thank the members of this board for the incredible amount of usefull information, especially regarding battery testing.

I've just bought a Maha MH-C9000 WizardOne charger and 2 sets of 4x AAA eneloops to start. I'll be waiting a few more days before my ebay seller starts carrying the new 2400 mAh LSD Imedions to build my AA stock.

I've immediately done a break-in on 4 of those AAAs. The charger reported 1 battery around 700 mAh but the other 3 were in the close vicinity of 670 mAh.

• a) Is this normal?

After reading a few posts, I've taken those same 4 cells and I'm discharging them at 200 mAh before I do another break-in.

• b) Should I expect a capacity increase after this?
• c) Would a Refresh&Analyze be nearly as effective as the second break-in?

TIA

Hi, :welcome:

First, see what capacity is reported when you finish your 200 mA discharges. If this has risen above 700 mAh you might try another break-in cycle. For future reference it is always worth doing a complete discharge before starting a break-in cycle since the discharge step contributes to the value of this process.

If the capacity remains below 700 mAh it may be that you have old stock cells or possibly even counterfeit cells. New Eneloop AAA cells should be able to measure about 800 mAh on a break-in cycle.

Many people here will advise you to avoid Ebay when buying batteries. Unless you know the seller, it is very hard to be sure of what you are getting.

Not that I want to make this a downer, but remember please that the Maha 9000 charger is a "consumer device", not a high tech, carefully calibrated, professional measuring device. As such, manufacturing tolerances will allow for some variance in the performance of such a device. My Maha charger does NOT charge cells to their maximum capacity, which I have confirmed by having the same cells charged in a Titanium 8 cell smart charger. Batteries charged in the Titanium charger, will measure at least 75mAh or even higher than when charged in the Maha.

As others have stated, run the cells through another break in cycle, if the numbers improve significantly, you might wish to run another break in cycle to see if you get some more capacity...... if you didn't get more, the second time around, consider that your individual Maha unit may be reading on the low side, within specs but low, and that your batteries are fine.

I never run my rechargeable batteries until they are dry, only to the point of where I can tell it's starting to fade, at that point I swap the batteries out for fresh ones and recharge the depleted ones and will continue to do so until they fail to provide a reasonable service range.

We tend to get a little retentive on this board..... We keep forgetting that manufacturing tolerances are exactly that...... tolerances. Try not to get too hung up on YOUR specific numbers as they MAY NOT correspond to the numbers achieved by someone else. $400 Digital Multi Meters often do not agree on a measurement but they are each close enough to the truth, for their intended purpose. Your and my charger are NOT built to the same standard as a $400 multi meter so we have no right to expect the same tolerances.

Resolution and Accuracy are two different things..... just because we can resolve the capacity of a battery down to 0.001mAh does not mean that we are accurate down to the same level. The *realitive* accuracy is there, but not the absolute accuracy.

So... run whatcha brung, your 750mAh may well read 850mAh on another Maha, but in reality.... the battery remains charged to exactly the same level... it's only the meter that reads off, one way or the other.


Regards

Christian

kaptain_zero said:

Not that I want to make this a downer, but remember please that the Maha 9000 charger is a "consumer device", not a high tech, carefully calibrated, professional measuring device. As such, manufacturing tolerances will allow for some variance in the performance of such a device. My Maha charger does NOT charge cells to their maximum capacity, which I have confirmed by having the same cells charged in a Titanium 8 cell smart charger. Batteries charged in the Titanium charger, will measure at least 75mAh or even higher than when charged in the Maha.

Click to expand...

If I understand you correctly, you are asserting that one "consumer" device fails to charge cells to the theoretical maximum capacity by measuring charged cell capacity with another "consumer" device?

This assertion leaves me with a question: Is the second device a "high tech, carefully calibrated, professional measuring device"?

I'm assuming the answer to that question is no, which leaves open the question: which device is reporting more (or less) accurately?

If your ultimate point is that it really doesn't matter, I agree.

tandem said:

I'm assuming the answer to that question is no, which leaves open the question: which device is reporting more (or less) accurately?

If your ultimate point is that it really doesn't matter, I agree.

Click to expand...

No, neither device is a carefully calibrated device, and thus, in the great scheme of things, it really doesn't matter. What does matter is if there is continued improvement through several cycles of the "break in " charging algorithm. As long as a significant improvement is achieved, one should continue doing the recycle/discharge thing... BUT, if no improvement is shown, one has reached the maximum charge level. The problem is with this charge level being quantified as x mAh when the device doing the measuring, has not been certified to be "dead nuts" accurate.

I've noted in the past that eni time (Yuasa) AAA cells have been reported as *only* 750 mAh cells. If one reads the actual label on the battery, it states "Minimum 750mAh" which is actually the same rating as Eneloop AAA cells if I recall correctly. Sanyo does state that their AAA cells are nominal 800 mAh but they are specified to be 750mAh minimum.

With the tolerances in manufacturing of consumer equipment and the fact that the measuring side may vary from the charging side in the same device, 100mAh one way or the other should not give rise to any great concern (although a raised eyebrow might be warranted). On the other hand, if a person has 12 older AAA cells that report 750mAh after testing but a new batch of the same brand is only reporting 500mAh after repeated cycling in the exact same device.... there may indeed be a problem with the new batch. But the only reason we have for suspecting this is because we have calibrated the two lots of batteries against each other in the SAME DEVICE, not against other chargers and lots readings, which may be off from actual in either direction.

I guess I'm just getting my knickers in a twist over these reports of a charger being out of spec because of, for example, a LiIon was measured to be 4.21v instead of 4.20 v with a $20 Chinese multi meter.... I've done my homework, had my meters tested, and I KNOW where they actually read and can add or subtract to get the *actual * reading I need. And the best of my Cheapo Chinese meters reads a full 0.01v off... the other is 0.04v off in the opposite direction. I got a third meter, this one is a used, older but certified Beckman Industrial multi meter and I know it reads accurately in the range I'm looking at and I have confidence in that meter and it's capability of repeatedly giving the correct reading. I can't say the same for my cheapo Maha charger... yes, it's way better than most, but it's still not a professional grade device... it's made for the masses and to a price point... thus, components will only be spec'ed to a given tolerance and that WILL lead to one device reporting readings differing from the next.

That is my opinion based on my 54 years of living on this planet and playing around with electronics.... I am NOT an expert, but I did stay in a chain hotel last night which apparently has some effect on me, according an ad on TV that I saw. !


Regards

Christian

Aloha and wecome to CPF duartix! What is the date code on your eneloop aaa's? It should be stamped on the side of the cells and kind of hard to see. It would look something like 09-0610(June 2009) or 09-10HE(Oct 2009). I have 36 aaa eneloops/duraloops and their average break-in numbers are 792. I did do a full discharge first though before their first break-in cycle.

fishinfool said:

Aloha and wecome to CPF duartix! What is the date code on your eneloop aaa's?

Click to expand...

Thanks!
They're coded 10-03 YE so I guess they are around 5 months old...

Mr Happy said:

Hi, :welcome:

First, see what capacity is reported when you finish your 200 mA discharges. If this has risen above 700 mAh you might try another break-in cycle.

Many people here will advise you to avoid Ebay when buying batteries. Unless you know the seller, it is very hard to be sure of what you are getting.

Click to expand...

They're reporting around 760 mAh (and I had started the discharge cycle at 100 mAh for around 30m before I guessed they wouldn't be ready this morning - that's when I switched to 200 mAh) so I guess they should be close their nominal capacity (if not over!) as that first discharge try should add another 50 mAh...

About the eBay seller, this is someone in Europe with 100% positive feeedback, his eneloops are HR-4UTGA , he also sells Imedions and this is someone whose Maha chargers are tagged newest version: 0J0DA so I guess the chances of fakes are all so slim.

My last question and since all numbers point in the general direction of a second break-in:
Would a refresh-analyze do the same job? If so what charge/discharge rates would you recommend?

Thank you all! Great advices in this thread!:twothumbs

duartix said:

My last question and since all numbers point in the general direction of a second break-in:
Would a refresh-analyze do the same job? If so what charge/discharge rates would you recommend?

Click to expand...

Anyone?
TIA.

duartix, chances are that a second break-in will be more beneficial than a refresh-analyse if you are trying to stretch the cell's working capacity just a little further. Having tried various combos of discharge/charge current on refresh-analyse vs a full break-in cycle it's been my observation that a discharge and break-in run for new batteries works best so I'll assume that will hold true for a second break-in of new(ish) cells.

But works "best" for Eneloops (and Imedions) might not be that much different than an alternative, faster, approach to getting on with using them.

My recent experience with Duracell labelled Eneloop AAA's (date code Dec 09) has been that, when in a hurry, if I just use them (or run discharge) and then perform a refresh analyse rather than break-in the reported capacity tends to be within 20-40ma of 800ma. More often than not when performing a break-in I get 800ma +/- 10ma.

A recent purchase of 16 Imedion AAA 800ma cells saw every single cell report > 800ma capacity during the initial break-in process. I was pretty impressed; the AA versions of those same cells are not typically so consistent (but good just the same after break-in).

I think if I were in your shoes I'd just use the cells you've already broken in and then when they need recharging put them through the break-in process again. Label them so you can keep track of what needs doing later.

Thanks!
I'll put them through another break-in then. Even though I'm in a bit of a urge to put them to use, I haven't paired them and that's a priority.

duartix said:

They're reporting around 760 mAh (and I had started the discharge cycle at 100 mAh for around 30m before I guessed they wouldn't be ready this morning - that's when I switched to 200 mAh) so I guess they should be close their nominal capacity (if not over!) as that first discharge try should add another 50 mAh...

My last question and since all numbers point in the general direction of a second break-in:
Would a refresh-analyze do the same job? If so what charge/discharge rates would you recommend?

Click to expand...

If your cells are reporting a nominal capacity of abut 800 mAh as you say here, then your job is done. You may as well start using them. Further conditioning or cycling will be of little benefit.