Discharge curve for Eneloops AAA?

skyrider1 · December 4, 2013, 5:02am

Does anyone have a discharge curve for the triple A eneloops at different currents? I’m wondering what kind of current draws they can handle and the capacity/voltage drop from higher currents.

skyrider1 · February 9, 2014, 10:17am

bump

HKJ · February 9, 2014, 10:31am

I have it on my to do list, but it will probably be a couple of months before I get to it.

Lithium · February 9, 2014, 1:56pm

I can do some for you, what current do you want? I can do 0,1-2A (well 0,1A will be very long so…)
Keep in mind that I am NOT equipped like HKJ, and I only got one Eneloop AAA 800mAh (gen 2)…will be just indicative

skyrider1 · February 9, 2014, 8:10pm

Thanks HKJ!

Thanks for offering! I can wait for HKJ if it’s too much trouble but a test at 0.5 and 1.5 would be nice. I mainly want to know about where the max current would be before you get a major drop in performance (capacity/voltage) or something or that sort. Building a drop-in for an L2M and just wanted some data first.

pipifax · February 9, 2014, 8:41pm

maybe this is sufficient?

http://www.eneloop.info/home/technology/data-sheets.html

skyrider1 · February 10, 2014, 7:12am

Thanks, didn’t think about searching for the actual data sheet.

rojos · February 10, 2014, 8:40am

Thanks for the link pipifax. I didn’t know Eneloop data sheets existed either. Pretty cool.

Lithium · February 10, 2014, 9:38pm

Here is the curve @1,5A : http://tof.canardpc.com/view/27410d4a-a33c-401d-8c13-2b990536a7c8.jpg

(Eneloop 800mAh gen2, pretty new, I’d say 10-15 cycles).

Measured capacity @1,5A is 751mAh, quite good even is the voltage under load is low. Please note that I haven’t bothered to log the temperature, but the Eneloop became only slightly warm (~25°C max).

Edit: also note that the charger don’t log under 1V (don’t know why…crappy charger), but I set the discharge to stop at 0,8V (and it indeed stopped at 0,8V, just that I don’t have data under 1V)…humm now I see the curve is pretty useless, sorry
If you can wait another week, I’ll grab another charger.

skyrider1 · February 10, 2014, 9:35pm

If its too much trouble its ok. I doubt I’ll pull more than 1.4A from it and if it can hold 751mah with decent voltage at 1.5A then I am good. Thanks

Lithium · February 12, 2014, 2:58pm

That was faster than I thought.

Here is another test @1,5A, using an Hyperion Hobby charger (which I’ll trust much more than the charger on my previous test).

This time I got 746mAh from the Eneloop, cut off voltage 0,6V (yeah I know, I set it a little too low!). Max temp 24,4° (around 20° ambiant). Notice that the voltage sag is lower this time…either the Eneloop is now “accustomed” to such discharge rate, or the internal loss in the charger/contact is much lower :party: