dropping NIMH batteries

I heard that you should not drop the NIMH cells, this will damage them; I am not sure what that means, what happens, capacity or lifetime (number of cycles) suffers (or both?). Does anyone know of any guidelines about this, what height, what kind of impact, etc. I just dropped a brand new set of AA Eneloops on the carpet from a height of almost two feet. I hope they're not dead... Thanks

dropping them from 2 feet on a carpet most probably won't cause any damage to the cells. Heavy impact, however, may cause damage to the separator. This causes higher self-discharge and increased internal resistance.

the ones i destroyed were from the height of the human hand to the concrete. but how where and what got hit , i dont know.
i dropped a few in the garage when changing them around, and 2 of the ones i droped started having high self discharge.
so IMO 4 feet on a hard surface can do it, but mabey its more than that, i am not taking the chance.
same thing happened with a camera battery at least once (li-ion) passing them from person to person, the thing slammed to the ground, and it still worked, but then it quit working so well. because its a SERIES pack a minor inbalalance caused it to last less time and fail prematurely.


Mr.Nimble fingers

So I dropped an AA Eneloop on a hard surface floor, sucks!

i drop batteries almost eveytime i handles them. that sucks it is something about their round shape maybe or just my luck. :sigh:

Absolutely don't drop rechargeable batteries.

I'm sure I've read something about this on the Eneloop FAQ:

Q: Can Eneloops be damaged by dropping onto a hard surface?
A: Yes. Don't do that.

Or words to that effect...

rizky_p said:

i drop batteries almost eveytime i handles them. that sucks it is something about their round shape maybe or just my luck. :sigh:

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I've got rheumatoid arthritis, so when I'm having one of my bad days, I make sure I am sitting down and over a carpeted surface when I handle the batteries....if they do fall, they don't drop as far and have a slightly softer landing.

Now I have to worry about this too :ironic: I never knew such a drop could hurt nimh batts. And I don't have enough patience to put batteries away and test them for high self discharge. What about all the times I drop my flashlights? I must have a lot of bad batteries.

mighty82 said:

What about all the times I drop my flashlights? I must have a lot of bad batteries.

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Exactly what I was thinking! I have bats with large dents in the bottom from being dropped!

Any fall onto a surface hard, is definitely enough to cause some problems (i.e. accelerated self discharge, capacity problems, etc.), especially if it is hard enough to actually dent the cell. Denting the sides would most likely be the worst place too, when compared to the ends.

Falling onto a soft surface like carpet, etc. no problem.

I've had them roll off the counter onto a slate tiled floor almost routinely, and have yet to see what I would deem aberrant behavior in any of my cells.

Except, of course, for the infamous Energizer 2500s.

As long as there are no external signs of damage to the container or displacement of the positive post, I agree with Turak that the odds are the cells survived the fall intact, and that this is especially so with the sturdy Eneloop.