:person_facepalming: 
these four i tested wee older cells, 2 of them laptop pulls, one a sanyo with high IR, and a Ultrafire with the protection removed. They all got extremely hot, but none vented with the various overload of voltage and charging amps, or shorting.
I'm not surprised. We tried to vent a lot of different brands of 18650s via overcharging and shorting. All of the fail safes went off. The only way I got something fun to happen was lighting them on fire in a cup of flammable liquid.
Not sure why this 25R vent so quickly.
www.youtube.com/embed/GM4R_152Mp0
I thought that in order for the cells to vent with flame they needed to 1. be discharging and 2. reach a temperature during discharge to trigger thermal runaway.
Some information on battery university reads that li-ion with cobalt cathode becomes thermally unstable at temp of 302 Fahrenheit, and li-ion with manganese cathode become unstable at 482 Fahrenheit. Perhaps you can get a cell up to these temps with the torch you have planned. 
I think the best method to reach the desired result is a dead short with very heavy gauge wire or metal.
I believe many youtube attempts at creating vent with flame do not take into consideration that it is based on a chemical reaction which occurs under specific conditions.
I compare this (comically ) to how a nuclear reactor will not reach meltdown condition by hitting reactor with hammer or shooting it. :+1:
Wow these must be grade A cells how much to buy them after they pass your torture test. I’d love to strap that ultrafire to my head in my armytek…… :person_facepalming: 
indeed. i will be testing to vent them later today using a blow torch remotely.
Crushing the 25R probably breaches the containment membrane that keeps the two reactant chemicals separate.
The eventual failure of that membrane from slow crystal growth that pokes a hole in it is the problem described as leading to failure with venting and generation of heat, and the chemicals used are flammable.
The eventual failure is described as happening from heat cycling and age, and as a problem with counterfeit cells or cells made in dirty conditions with metal fragments that cause a variety of problems inside the cell over time.
If you look up “accelerated aging” as a test procedure for li-ions, you’ll find various descriptions.
The membrane separator, if well made of the proper material, isn’t likely to fail quickly solely from external heat being applied, and if the liquid inside boils off through a proper vent releiving internal pressure, into an external fire, it will just burn off (though you probably don’t want to breathe downwind.
Part of the question is that there as yet no standards for producing li-ions, so you rarely know what you get or whether it has been tested. The brand name cells have gone through the accelerated aging/cycling tests and they’re careful about manufacturing to specification without corner-cutting, for that reason.
Have you weighed the cells before and after heating them, to determine whether they’ve lost any of the contents through proper controlled venting when heated?
UPDATES! - July,4th,2016
Successfully got some 18650’s to vent, by applying heat from a propane torch remotely. after two vents, i successfully got a cell to vent inside a flashlight! The light was a metal tactical design, but with a side clickie switch. it melted the switch, then vented enough to blow the driver, reflector, and LEDs out the front. I captured the tests on video. as soon as i return from my holidays i will upload the videos of the tests. I also tested a AAA Alkaline and a AA Zinc Carbon with the heat test.
Lol!!
NO! Post it now!!
Were the flashlights turned on when they exploded or no?
Can’t wait to see the videos!!!
yep, it was turned on. its in the video where it goes out roughly 5 minutes before the cell vents in the light.
Cool……this should be classic!
I’m interested in this. I also want make tests like that. I made a polycarbonate box for my phone to take 720p 120 fps videos from some exploding things at a very close distance
Looking forward to the video.
Well crap… Now I don’t know what to do. You guys talked me out of making the 18650 golf ball cannon, because li-ions just won’t vent with force… But now they do???
I cannot wait to see the videos. Thank you my friend to the north.
from my tests LiIon cells vent more like a model rocket motor (or a small fireworks fountain) outside of a flashlight or unsealed battery holder.
inside a sealed flashlight body its a different story.
From our observations the plastic switch assembly or plastic lens/reflector in cheaper lights will blow out releasing the pressure before they can build up enough pressure to explode the metal body like a metal pipebomb. in a stronger more sealed light, substantial pressure could build up before the tail cap, switch spring metal plate, or driver/star/reflector/lens would fail causing a “burst” explosion sending some shrapnel out with force.
even in the cheaper light i tested, the plastic side switch & rubber cap blew out with some force ejecting parts, (to fast for the cameras to see) and knocked over the holding jig we built to hold the light from jetting away like a rocket.
This sounds like so much fun I can’t wait to see the videos.
Your results with 12V charging are not that surprising. It is very similar to some tests the manufacturers do, except theirs last hours.
I had a 18650 cell vent in a Convoy C8 yesterday as my car burned up. There was enough force to eject it from a closed center console to just outside of the open car door. Will try to get vids or pics from family who were there- I have none myself. Was similar to vid’s I’ve seen with sparks ejecting etc. for about 4 seconds.
Looking forward to your Vids DBSAR
Phil