Batteries dropping to less than 0.7 Volts in torch

matyr · 2019-11-23T13:49:31.000Z

Hey so i have an energizer 2 x AA torch and eneloop AA batteries. I recently decided to do a test because i was curious how long the run time would be with the eneloops.
I left it on overnight and woke up and it was completely dead. I was surprised because energizer saiys the torch lasts 60 hours with regular alkalines and mine lasted less than 8 with eneloops.
But the weirdest thing is i put the batteries in my charger and both were showing .69 Volts but after just a couple seconds jumped to 1.3 volts.

I’m worried because i heard you shouldn’t discharge Nimh batteries to less than .9 Volts because it can damage them but i’m not sure if they’re actually getting that low.

So does anyone know why the run time is so low? Why they’re showing up less than .7 Volts but rapidly going back to 1.3 +? If it’s safe to keep using this torch?

Btw the batteries are made in Japan white eneloops and the charger is a nitecore D4 so i don’t think they’re the problem.

Cheers

BlueSwordM · 2019-11-23T16:10:41.000Z

Hmm, that’s strange

The reason the light will last “60” hours with alkaline is that their internal resistance is so high that brightness will not only drop linearly over their discharge(since that’s what alkaline cells do), but also drop a lot. So that figure is only valid for alkalines, not NiMH cells that will keep a high constant brightness.

Anyway, do you have a multimeter to check their voltage out?

I have a feeling the light discharges that lower to get maximum capacity out of alkalines, and not caring about anything else.

Barkuti · 2019-11-23T17:35:18.000Z

matyr:

…

But the weirdest thing is i put the batteries in my charger and both were showing .69 Volts but after just a couple seconds jumped to 1.3 volts.

…

A couple seconds may be a little bit exaggerated but that is pretty normal. Ni-MH has a very sharp drop in voltage when it is out of energy. As an example:

Eneloop AA BK-3MCCE 1900mAh (White) 2019 @ lygte-info.dk

On the other hand your cells will be fine.