Curious_character
Flashlight Enthusiast
- Joined
- Nov 10, 2006
- Messages
- 1,211
Suppose I have a light that uses two CR123 cells, put it in my household emergency kit or (worse yet) automobile glove box, and forget it for a couple of years or more. It seems to me that even if the cells start out pretty well matched, they might end up deteriorating and self-discharging at slightly different rates. If so, when I finally go to use the light, the cells will have mismatched capacities and one will run dry before the other. Isn't that a setup for an explosion or other violent event?
A flashlight designed to use only two CR123 cells might also be designed to turn off when one cell gets very low and before either can go completely flat, so the strong cell wouldn't be able to reverse charge the other. But a light designed to also work with a single 18650 cell wouldn't shut down even after the weak cell was completely drained.
So my thinking is that flashlights designed for and using two lithium cells shouldn't be used for long term storage, unless designed only for two cells and tested to make sure they shut down at a high enough voltage to insure that neither cell can be completely discharged. And if my conjecture about uneven self-discharge is true, a three or more cell light shouldn't be used at all. (Unless the batteries are rotated regularly to keep fresh.)
Protected rechargeable cells or ones with safe chemistry should be ok, but I'm thinking specifically of lights using CR123 primary cells or unprotected standard rechargeable cells.
Could any of the unfortunate explosion/fire events have been caused by this? Or is this a non-problem?
c_c
A flashlight designed to use only two CR123 cells might also be designed to turn off when one cell gets very low and before either can go completely flat, so the strong cell wouldn't be able to reverse charge the other. But a light designed to also work with a single 18650 cell wouldn't shut down even after the weak cell was completely drained.
So my thinking is that flashlights designed for and using two lithium cells shouldn't be used for long term storage, unless designed only for two cells and tested to make sure they shut down at a high enough voltage to insure that neither cell can be completely discharged. And if my conjecture about uneven self-discharge is true, a three or more cell light shouldn't be used at all. (Unless the batteries are rotated regularly to keep fresh.)
Protected rechargeable cells or ones with safe chemistry should be ok, but I'm thinking specifically of lights using CR123 primary cells or unprotected standard rechargeable cells.
Could any of the unfortunate explosion/fire events have been caused by this? Or is this a non-problem?
c_c