I’ve seen all the posts about 18650 batteries catching fire in chargers …going bang etc notice that there is never a picture of these occurrences …ever ……as an experiment i put a charge of 5 amps into a 18650 battery it got warm as expected then hot after a very short time then began venting as designed to do….slight hiss could be heard……
Lots of fairy tales abound about 18650 batteries…….dont worry they do not explode or catch fire
Jim
Unfortunately, some of the cheap cells are lacking the safety mechanisms, such as proper vents, & the circuit disconnect.
The 'explosions' are due to the cell/s venting whilst being in a sealed enclosure aka a flashlight.
Most problems seem to arise from cells in series configuration, & of unequal charges.
Ask this guy about it;
They can explode. But haven't seen cases of good quality brand cells doing this (without being damaged).
See: http://www.candlepowerforums.com/vb/showthread.php?280909-Ultrafire-18650-3000mA-exploded
How could the torch explode when the battery was in the torch and not being charged or venting
jim
How do you know it wasn’t venting? The same O-rings that keep the water out keep the pressure in. I’m sure if a battery tries to vent and can’t…something bad is bound to happen.
There was pics on CPF of an exploded flashlight caused by L ion. How toxic is the vented gas? I know the fumes from a l ion fire are extremely bad for human health and can cause life long problems
Jim… welcome first of all. Second, no.
While it is typically very difficult to elicit a QUALITY cell to vent, or vent with flame, it is entirely possible. Much more likely with low quality, fake cells.
That is no reason to be careless or let ones guard down.
Cells that may be venting inside a sealed light (torch) will build pressure as the gas is produced and released… with nowhere to go, it becomes a pipe bomb. Consider all of the e-cigarette explosions that are discussed on the internet… same thing.
Even still, assume no explosion, the gases released are INCREDIBLY dangerous and even a few seconds exposure will permanently damage your lungs in ways you would never believe until it happened. Inhalation of the gases produced could cause death.
Cells don’t vent or fail only when charging, but also while discharging, and sometimes for no good reason at all. If the cell becomes shorted, internally or externally, you’re in for a bad time.
Here’s one, with pictures: http://www.candlepowerforums.com/vb/showthread.php?262234-TK-Monster-Explosion
Another incident: http://www.candlepowerforums.com/vb/showthread.php?340028-Flashlight-Explosion
Heck… just head over to CPF and read the ENTIRE sub-forum dedicated to this type of event.
Okay to be on the very safe side i have just drilled a small vent hole in my ULTRAFIRE XML-T6 torch
jim g4rek
Don't forget to remove the battery before making a vent hole. ;) wink2x
Of course and de-burred inside torch
jim
You couldn’t have searched very hard, at all. Or your google-fu is pretty poor.
If you have trouble believing the risks then I recommend you do not use li-ions at all. Stick to AA ni-mh rechargeables.
Yep, hydrogen fluoride gas. Plus a few other nasty chemicals. Hydrogen fluoride transforms in hydrofluoric acid as soon as it touches skin, eyes or the inside of your lungs.
Just when I’d got to the point of being able to sleep at night with 18650s in the house this thread happens! |( 
lol… yeah… when you really get down into the dangers of lithium-ion… it makes my wife ask WTH we have them in boxes next to my side of the bed, or in the house at all.
I use a lot of old laptop batteries in my 18650 lights and store them in drawers when not in use. Is it a good idea to keep them in a metal fireproof container or should I not worry about it? I’ve got a couple small fireproof safes I’m not using.
I have about 40 laptop pulls I keep on hand. I just store them in various plastic containers. I found some crayon cases on clearance at Wal-Mart that work well if you strap a rubberband around them… or the two-cell colored plastic cases with snap latches on Amazon work great (I use those to keep in my travel cases with the actual lights as spares).
While I certainly would never argue that they aren’t at least a little dangerous, I do wonder if maybe it’s a little over hyped.
I always remind myself that hundreds of thousands of people are using laptops every day, with 6 or more 18650s sitting directly on top of their baby makers without giving it a second thought
Original laptop packs only use high quality cells with intelligent protection. And even then there has been fires and massive recalls. Can’t compare them to all the random cells people use.