Left light on for a couple days on low, will it damage the battery?

When i realized it i turned it off and checked the voltage, it was down to 3.55 volts (no load), and i forgot about it for a few days at that voltage, and tossed it on the charger today, its taken about 10 hours to fully charge at 600ma
Its a King Kong INR 26650

If you’re voltage measurement of 3.55V is correct, it shouldn’t be a problem for the battery.

Li-ions are considered depleted at 3.2V but may occasionally be discharged to 3.0V too.

Cheers!

+1, the NCR series can be discharged down to 2.5 volts though.

Yeah, but thats the voltage with load, not unloaded like he measured. 3.55 should still be safe.

Thanks everyone, apparently the bezel wasn’t tacticool enough to remind me i forgot to hit the off switch :cowboy_hat_face:

if the battery hasnt leaked no damage visible its just means u running it low and can be fully recharged again. mayb try do few cycles through your hobby charger see if the capacity is still good. ? let us know whats going on hey :slight_smile:

there was no leak, and i don’t have a hobby charger, just a 600ma plug in dowacky
it seems to run fine in the light since being recharged though

My GP LSD battery has died.
I have left in a flashlight, and that deep discharged the battery by accidental on.
I can not managed to charge it, it shows negative 0.40V on DMM. I mean it swapped positive to negative.

keeping cells that voltage (3.5V) extend its life

li-ion cells can discharged to 2.75V. but its not good to keep below 3V state long time.