Is overdischarging an 18650 dangerous?

Batteries and Chargers Rechargeable Batteries
1

I know that overdischarging a Li-Ion cell reduces the life or can totally kill it, but is there any danger with overdischarging? I read in another thread that it was dangerous but I always thought the only danger was overcharging???

2

No just don't charge it after. I assume you mean a single cell and at a controlled discharge at reasonable current drain?

3

Yes it could become dangerous when you charged it again

4

Today my charger and a pair of Trustfire protected 18650s came in the mail. I have no idea how long it takes to charge a bettery from about 3.86 V to the 4.1-4.2 Volts for a full charge. I do not want to leave it on after I go to bed so will disconnect the charger.

If the batteries have not reached the charged voltage which shuts off the charger, can I plug it in again tomorrow without danger of either ruining the battery or it exploding?

Thanks,

Jerry

5

You can do that. Topping up is not an issue

6

Thanks, edc.

Jerry

7

I have noticed that a foil-packed Li-Po, when it gets overdischarged, puffs up (which means there's internal pressure build-up). As that's not evident in 18650 form factor (due to hard metal casing), you may be thinking that overdischarged battery is completely safe, while in reality it may be not (if internal pressure build-up gets too high, it literally turns into a pipe-bomb).