I've been the owner of many-a-battery which blew up, particularly inside of flashlights.
I've recently purchased a fairly-decent-quality flashlight, and I'd greatly like to prevent the battery from exploding/leaking inside of my expensive flashlight.
As a reference, here's the battery that I'm using:
(source: nitecorespecialist.com)
Why do batteries leak/explode, and what can be done to prevent this?
Best Answer
Cause
Thermal runaway is the main cause of lithium ion battery explosions. Once too much heat is generated, that causes the reaction to happen faster which generates more heat which causes the entire cell to start burning/exploding. This can be caused by poor manufacturing, an internal short caused by improper charging, or improper usage.
Leakage is caused by the same basic causes as stated before, but it's usually milder in effect and is due to heat or chemical reaction causing a boiling of the electrolyte or a chemical change which increases the pressure of cell. There's usually a safety valve that releases once a pressure is reached and out comes electrolyte and electrode materials. Once the safety valve goes usually the battery is toast.
Prevention