From my understanding on this, the gasses developed in a venting 18650 are created so rapidly that you’d need some huge holes to prevent pressure build-up within the light body. Many small holes might help or might not, this kind of gas production nears a low-velocity explosion and any kind of restriction will have a notable effect no matter how small that restriction is.
Having said that, the actual chances of you experiencing this kind of an issue are minuscule if you use good cells wisely. The real danger of LiIon venting is the hydrogen flouride in the vented gas itself- you must know when not to breathe as even a small amount of that stuff in your lungs can make the rest of your life permanently miserable. Large quantities will make your remaining miserable life short.
Cells will heat up before venting. If you have a light in your hand and it heats up suddenly you will likely notice and be able to toss it safely out of range or remove the cell before it vents and/or causes the body to explode. If you’re not holding it you still get the HF gasses and flames. So really, I can’t see where drilling a flashlight body for this reason would be of much use at all. Just my $0.02 and YMMV but remember that I have watched my C8 with an 18650 in it go boom in a car fire so I’m not just speculating here
@sawmaster: I was thinking that to, that the light would heat up so hard you’d just throw it away. That’s why I didn’t understand all the accidents with vaporizers blowing up in peoples faces. But apparently the space between the battery and the body of the flashlight/vaporizer is enough to act as insulation so that the battery heats up significantly faster (and more) than the body of the FL/Vaporizer. This could be the reason that people still use their vaporizer and have it blown up in their face before they even realize somethings wrong with the battery.
Whilst not meaning to play it down to much - using/charging li-ion cells should always be treated with care and respect,especially if more than one in series - but to put it in perspective using a well respected torch like the s2 with a single quality 18650 cell that you know the history off, is probably up there with putting on a pair of trousers in terms of user safety/risk for especially someone who’s taken the time to join blf and enquire about safty
So personally I’d take the normal precautions you would/should with something powered by li-ion and not worry about it to much
I am uploading a video we did last year during that test day, only this one is a close up of an 18650 cell venting from over heating. ( will post the link as soon as it uploads.
That’s the one, thanks Barkuti. It’s probably a thermal fuse. HJK didn’t seem all that surprised by it opening, just noted that it did its job properly.
It would probably be best to devise a way that the lense o-ring blows out but not allow the glass to move forward and block the venting path. That stuff needs to be directed away from your hands and face. The hardest part would be getting a big enough venting path through the driver board and pill.
The few modded lights that I have run pretty hot on turbo and the cell would be shorting out inside the battery wrapper. I don’t know if I would detect a problem in time, chances are the thermal fuse would open up and I’d be trying to figure out why the light stopped working as it started to vent.
At least you would have some warning, the battery tube would be warm with the light off.
I’m not that worried about my flashlight going nuclear, its possible but its more likely a battery in something else fails first. There’s lithium batteries in everything these days from shavers to laptops. My work truck has about 120 18650 cells in various battery packs. If one of them goes rogue and causes the other cells to vent at night on the highway its going to look spectacular. My Samsung S7 phone had a faulty mainboard. Turn the phone off at night and plug it in to charge it would crash and max out the CPU all night. Scary hot in the morning, went back to Samsung four times before they decided reflashing the firmware wouldn’t fix it. They never opened the phone to check on the condition of the battery even though the repair tag had overheated, check battery among other things on it. It seems that if you buy something from a reputable manufacturer they feel pretty comfortable with all the built in safeguards. Given the number of batteries out there and the small failure rate they are probably right.
I had a imedion nihm vent in my ea41 on low just above moonlight. I heard a hiss and the light went off it pushed the switch cover up. I was able to get it back in place. I’d say the switch boot will go first. Just from experience. Havnt purchased imedion cells since the other 7 or fine. I will add it was my fault. After about 20 cycles the cell wouldn’t register in my opus nihm charger or the 3100, liito 100, 202, and xstar. So I used a dumb charger after 5 mins the opus would recognize it. About 30 cycles of forcing it to charge is when it finally vented at very low amp draw. So the cell did give me ample warning I just ignored it. These new chargers are pretty good at dectecting if a cell is bad or not. Now if a charger won’t recognize a battery I trust it and dispose of it
My vape unit has holes in the bottom of the battery tube.
A small hole anywhere in the battery tube with a rubber grommet or any similiar would work. Can be a tiny hole. Its going to take the path of least resistance. In my case was the switch since the o rings did their job
