Hi all,
just this quick question becauese it might be very important.
When buying the dry i also purchased my first set of unprotected cells (http://www.cnqualitygoods.com/goods.php?id=1184)
But when going outdoors you can't expect someone so know the voltage all the time..
So my question is simple: what happens when you put a bunch of unprotected batteries in a flashlight and leave it on (not discussing heat)?
Thanks in advance! Just don't want to damage my cells or blow my hands off :d
I think you mean overdischarging rather than undercharging?
If i got it right you mean overdischarging as mentioned above. Well it's a bad thing to do. When the cells reach around 2.5V they start to damage itself by a chemical reaction. You can discharge them even lower if you wish tho. Trouble is they will probably vent when charged back again if left under 2.5V for some time. You may be able to dicharge them to 2,6V safely all the time and recharge them quickly after reaching that voltage. It is highly unreccomended. If you use 3 such cells in serial config chance are that some will discharge even lower. For multiple li-ion application go protected. I wouldn't dare to go unprotected for such application for the fact that you cannot possibly know in an easy way how those batteries have degraded in term of capacity with time. Immagine a scenario when you run 3x 18650 same type and brand in a flashlight and with time one has 2200mAh capacity left, the second 2150mAh left and the last 1800mAh left. See where is this going? When you discharge them in the flashlight and the output drops noticeably enough that you know its recharge time, one of the cells can be in the 1,9V already. I would suggest a house insurance and evacuating the room before attempting to charge it again.
Use quality proven protected batteries for such a task, preferably matched capacities (thats why quality brands).