Eneloop AAA Losing Major Capacity - Any Ideas Why?

[45/70]

From what you guys are saying, it's clearer to me now, how the Sanyo Harmolattice cells would be a viable alternative to regular LSD cells. I don't run my newer cells in low drain devices. I just use older cells that they have replaced, or "crap cells". In these devices, they've always worked quite well.

Most devices that I use my newer cells in all draw enough current that, I suppose anyway, is why I've not run into the problems Ziemas and others here have experienced. Thinking more about how I use AAA cells, I run proportionately higher current from them than my AA's, eg. 2C+ at times, and I'm sure that has a lot to do with their seemingly short cycle life.

Justin Case, I see my attempt at a humorous post failed. Sorry about that. I'm sure you and many others here have more knowledge than I about cell chemistry, behavior and so on. I was just messin' wid ya!

Your snide remarks demonstrate a remarkable ignorance, fairly typical of UI people like yourself. I note that you seem incapable of discussing the factual aspects of the definitions of the terms you are using. The fact is that formation <> growth, and it is clearly grain growth that is the operative mechanism. Your "proof" that "crystalline formation" is correct terminology is an appeal to authority argument, which is fallacious. I can find plenty of references that refer to grain growth, not "crystalline formation", from DOD and academia. So what.

Not sure what endeavor you refer to. If you mean enlightening you, you are finally correct in something -- it is hopeless.

So anyway, thanks for the kind words, and lighten up man!

Dave

 

[Ziemas]

UPDATE:

After five rounds of a 800mah charge and discharge cycle there is no discernible difference in capacity. I've now got them on a 'break-in' cycle on the C-9000 to see what the rated capacity will be to compare apples to apples, but I have little hope of seeing any improvement.

I must say I'm rather disappointed that such expensive cells, which have been properly taken care of, should have such a short life.

 

[45/70]

Ziemas, I'm curious, do you have any idea what the voltage was of your cells, after discharge in your light and speakers? I ask because I'm wondering if it's possible that some were over discharged and thus, damaged a bit.

I know when using cells in series in low drain devices, my IR mouse for example, it's easy for one of the cells to go way to low, before you're aware of it. If this happened repeatedly, even just a little, this may explain why some of your cells are coming up short.

Dave

 

[Ziemas]

Ziemas, I'm curious, do you have any idea what the voltage was of your cells, after discharge in your light and speakers? I ask because I'm wondering if it's possible that some were over discharged and thus, damaged a bit.

I know when using cells in series in low drain devices, my IR mouse for example, it's easy for one of the cells to go way to low, before you're aware of it. If this happened repeatedly, even just a little, this may explain why some of your cells are coming up short.

Dave

Honestly I have no idea, but I charged them long before they ran out of juice, so I never ran them all the way down.

 

[Bones]

Honestly I have no idea, but I charged them long before they ran out of juice, so I never ran them all the way down.

Considering the discussion in this and other threads respecting the discharge cut-off point of the MH-C9000, perhaps you should consider some form of deeper discharge of the cells as suggested by Mr Happy in post 2.

If you've never let them fully discharge, and charger can't discharge the cell deep enough considering it's 0.9 volt cut-off, it may make a difference.

As well, it's my understanding that optimum crystal break-up is achieved through fast charging and slow, deep discharging, as set out in this post by SilverFox:

http://www.candlepowerforums.com ... post2391945

One way I've tried to achieve a deeper discharge is by repeatedly discharging a cell three or four times in row at the MH-C9000's lowest discharge rate. If the cells are allowed a rest period in between discharges, they seem to recover enough for another measurable discharge.

 

[alpg88]

i thought crystallization only happen in nicd.
in nicd i fix it quick and easy, flash circuit from disposable camera, and 2 nails, i zap each cell 2-3 times, than it becomes almost as good as new, never tried to fix nimh, or liion like that.

 

[45/70]

i thought crystallization only happen in nicd.
in nicd i fix it quick and easy, flash circuit from disposable camera, and 2 nails, i zap each cell 2-3 times, than it becomes almost as good as new, never tried to fix nimh, or liion like that.

Hey alpg88, you are confusing dendrites with crystallization, as I once did (checkout the thread in Bones link). Crystallization does however, occur in both NiCd and NiMH.

Dave

 

[45/70]

Honestly I have no idea, but I charged them long before they ran out of juice, so I never ran them all the way down.

Well, if you had run them all the way down, depending on the circuitry involved (I'm guessing simple DD in both instances), that certainly would have caused damage. I just thought maybe there may have been some instances where a "borderline" situation had occurred. Sounds like you have made sure that didn't happen though.

Dave

 

[Ziemas]

Well, I've tried all of the suggestions here and there is no change at all. I guess the batteries are ruined. Quite disappointing, really.

 

[TorchBoy]

I guess the batteries are ruined. Quite disappointing, really.

Yes, it's very sad but with only 674 mAh they're just no good. You'll have to send them to me.

No, seriously, thanks for this thread. I've got a plan of attack for some friends' cells.

 

[Ziemas]

Yes, it's very sad but with only 674 mAh they're just no good. You'll have to send them to me.

No, seriously, thanks for this thread. I've got a plan of attack for some friends' cells.

They'll be used in a clock or something, but they certianly didn't live up to my excitations of them.

Oddly it was just these three that are bad. I have other AAA that are just fine. Go figure.

 

[45/70]

Yes, it's very sad but with only 674 mAh they're just no good.

While I'm disappointed as well, I wouldn't go so far as to say that, Torch. All three cells are still delivering 80%+ of their original capacity. Even SilverFox wouldn't send them to the recycle bin yet!

Ziemas, what I'd do is run them in some higher current draw device for a while. If you have for example, an Extreme III, LiteFlux LF-2, or a high power LED light that uses a 3 AAA carrier, I'd run the cells in one of them for a month or two, then check and see how their doing. At any rate, I don't think it's time to assign them to second tier duty.

As I said earlier, it could just be that AAA cells have a proportionately shorter life than larger cells. Still, while it doesn't look good, it's not really time to give up on them yet!

Dave

 

[Black Rose]

As I said earlier, it could just be that AAA cells have a proportionately shorter life than larger cells.

I agree.

I've had a couple Rayovac Hybrid AAAs lose their LSD capability for no apparent reason.
Same thing recently happened to another brand of LSD AAAs I have.

All were used in low draw applications as well :thinking:

 

[TorchBoy]

While I'm disappointed as well, I wouldn't go so far as to say that, Torch.

I wouldn't either, and certainly not without the second half of my paragraph!

And FWIW my friends' Eneloop AA cells all test at over 80% (just).

 

[45/70]

I wouldn't either, and certainly not without the second half of my paragraph!

Well, I was kinda hoping maybe Ziemas would send them to me!

Dave