How many amps can a AA Nimh cell put out?

[aaronski]

I asked myself this question earlier today as I had recieved 70 of them from my old office. They might make for a cool booster pack, or some other foolishness. But how many amps can they handle? turns out, no one knows. Or at least I can't find it on the net anywhere, so, I tested them out results are as follows:

Energizer: 10 amps
Sony, Panasonic: 8 amps
eneloop: 7 amps
Duracell: 5 amps
generics: 2 and .2 amps
they are around 2.4 ah, but not nearly that good when pulling so many amps, but in theory, you could... who am i kidding, I'm going to toss them in a tube and try to make a 70s pack out of them. anyone want some *lightly* used NiMh's?

 

[texaspyro]

I've pulled 10+ amps out of them before... they don't like it at all. Melted the battery holder. Spewed battery barf too... whistled while they did it.

 

[liveforphysics]

I've pulled 10+ amps out of them before... they don't like it at all. Melted the battery holder. Spewed battery barf too... whistled while they did it.

That's just a batteries way of saying "thank you, I like this.".


candlepowerforums has a member silverfox. Nice guy. And he has done testing and posted data on pretty much every single AA cell on the planet.

 

[liveforphysics]

I suppose I'm entitled to advise you on the success your proposed pack will have.

Zero.

Putting unmatched NiMH cells in a series string = fail.

Charging NiMH in parallel = fail.

Mega cell reversals will happen in discharge.

Mega over-charge into venting will happen during charge.


If they were all lithium, you would have a shot at getting lucky. NiMH is actually a pretty damn tricky chemistry to deal with in a lot of aspects.

 

[Toorbough ULL-Zeveigh]

g'head, prove him rong.
if the cells be free it won't cost u anything cept time.

it appears u don't have the requisite experience to appreciate the steep learning curve ur confronting.
so altho ur chance for success is slim & not necessarily zero, yule definitely know more than at the start of ur journey.

one tip from the engineers of the Prius battery pak, only extract the middle 80% of a NiMH's capacity.
that way u avoid the problems associated with overcharge & overdischarge & the pack will last indefinitely.

the aforementioned CPF thread.

 

[aaronski]

I also have 20 4 battery chargers, I could, in theory, charge them individually and try and monitor the pack, but is there any reason to? Are there any advantages to Nimh over HK lipo?

 

[number1cruncher]

Are there any advantages to Nimh over HK lipo?

YES!!!!!!!!

 

[aaronski]

Are there any advantages to Nimh over HK lipo?

YES!!!!!!!!

says the guy running lipo and LiFePo...

 

[number1cruncher]

Are there any advantages to Nimh over HK lipo?

YES!!!!!!!!

says the guy running lipo and LiFePo...

Haha, fair enough. :wink:

BUT, I would go NiCad before NiMH. Luke is right, NiMH is a nasty chemistry and very picky. Usually very high self-discharge unless you get LSD(not blotter, haha) units.