Lithium ion is extremely dangerous.
I see no reason to get those 18650 time bombs in my house.
… hold on…
… 12000 lumen light you say?
… using four high drain unprotected cells?
… What’s the price?
… That low?
… That STUPID LOW with discount???
Ok people, I’m gonna order this light first, and then I’ll continue my rant. IT’S DANGEROUS I SAY!!!
For me, my happy medium is enjoying my flashlights to their fullest, but when they are in the house, I keep them in my safe place just in case. This way I don't become paranoid about it. I trust the manufactures to a certain degree, but won't risk my house on it. Even my laptop battery pack are in the garage as I always seem to find a place to plug my laptop into an outlet whenever I travel.
I had a lot of help from a member here bringing me up to speed about batteries and he said if the gases rapidly expand, the pressure would blow out the tail switch hopefully, so that is at least one pressure point that would give.
Especially with pocket-carry. Imagine an overpressure in a sealed Al tube, only finding escape through the weakest link: the front glass.
Nice, a shower of glass shards fired right into your crotchal area… 
—edit—
Oh, and at point-blank range, too!
And all y’all can go’head and dogpile on me, but that’s why I still prefer protected cells. It’s at least one more safeguard to keep Bad Things™ from happening.
Even with a light that ostensibly has LVP/UVLO, you never know when the controller will go mental and not cut off power if the light’s accidentally been bumped on and left for dead. At the very least, a hardwired circuit will cut off power instead, maybe not enough to totally keep the battery from getting stressed, but at least to keep it from going boom (or at least “pffffffft!”)
And even if you have a top-shelf light that cuts off power at >3V, you never know if the cell will get stressed from overcharging. Again, a protected cell is at least one more safeguard.
Show me a protected 18500 that can deliver 15Amps in my Quad EDC and I’ll consider it.
That’s just it: for the lights I use, I never push that much current, so I have the luxury of using protected cells. And given the choice of with/without, I’ll choose with.
But those are the lights I carry with me, or in my bag.
If I had an L6 or bigger, and needed that much current, well, no way would I carry a cinderblock of a flashlight with me all the time. 
It’d pretty much stay a shelf queen most of the time ’til I’d need it for something, then I’d use it, and then put it back (and optionally check/charge the cells). There’s almost no possibility of having it get bumped on and left unattended.
If I were carrying an EDC light that would pull 15A, you damned well better believe that unless it’s a twisty, I’d do a tailcap-lockout ’til it’d be needed. I wouldn’t want a China Syndrome in my pocket! (And, pull the cells entirely when it wouldn’t be used.)
I mentioned here a few times already how I managed to burn down a few AAs (alkies and Li primaries) when they’d get turned on accidentally in my bag and even in my pocket. And had an 18650 cooking my holstered EDC ’502 when I bumped the switch on a chair’s armrest. Thank B’harni (pbuh!) I felt the nice warm glow through the nylon holster, saw it was on, and turned it off.
Basically, no way would I chance an unprotected cell in a light that could be accidentally turned on.
(And yeah, I have a few 30Qs in addition to my protected Panny-Bs. I’ve got no problem using unprotected cells in lights that I can lock out when unused, or at least those I know I’d be around and notice in case they do get bumped.)
"China Syndrome in my pocket", now that was a good one lol. Kind of how I feel about it if I have a light in my pocket. I've read about those aluminum batteries that were supposed to be on the market in 5 to 10 years that can't catch on fire or pop and you can even drill in them and still they are safe, but somehow, that type of technology is probably going to be shut down by the utility companies that feel threatened by it would be my guess.
To each his/her own.
Each of us has to know our assets and limitations and work within what we are comfortable with.
I have lights everywhere. My charging is done on a bench in the garage in which I have a sprinkler system which won’t be much good for a Li-Ion fire but it makes me feel better.
I assume beacuse this line of discussion is on a L6 XHP70 thread we are talking about 26650s exclusively.
I think the best advice is I can give is this:
Li-Ion Chemistry is much improved but even modern batteries can have problems.
I personally have only had one battery give me trouble, it was a trustfire 18650 which got pretty warm discharging and the protection didnt work. Everyone here will tell you to stay away from the Chinese “fire” branded anything, especially batteries. That’s safest because from rewrap companies and chinese vendors, you really never know what your getting.
For 26650 batteries, I buy Liitokala almost exclusively and have never had one even get WARM. I have had good luck with the Efest Green 26650’s as well (4200 mah) which test very well. The King Kong/Keeppower 26650 4200 mah test extremely well too.
Nitecore, Klarus and other light brand companies make protected 26650s and they should make you sleep well at night but the price is tough to swallow.
Every battery in my house goes onto a tester/charger. Each cell gets a full charge and then a test. That’s a good practice to get in to.
Just my $0.02
Sorry to make my first post about this, but you got your facts wrong. Although they are called “Li-Ion-Cells”, they contain hardly any lithium at all (~5%). And the lithium that they do contain is not even metallic and thus basicly inert. Plus the cells are sealed - in a non-conductive fluid nothing would happen. What you see reacting is mostly the organic electrolyte. (Also E-Liquids do not contain water.)
Somehow it really annoys me that people still think of EV-batteries as something explosive. They are not. In most situations less probable to violently explode than any petrol-tank. The only really dangerous thing about EV-batteries is the voltage - don’t touch 600V and you’re fine.
I almost bought a couple of different Hybrids recently, they had 300 18650 Li-ion cells in a case mounted over the axle, eliminating a lot of space in the trunk. Same cells we use in our lights.
And I am not sure where your information comes from about the “inert” lithium in our cells, but I’m afraid you are mistaken. Far too many tests have proven what they do when venting or broken open and exposed to liquid. I’ve seen video of a vape unit overheating a Li-ion cell and the thing going off like a 4th of July fireworks display, spewing flaming Lithium everywhere and severely burning the consumer as he tried to run out of the store shucking his pants where the vape unit was in a pocket.
I don’t know much of anything about vape liquids. Was assuming they were basically water, if not, then what exactly is everyone turning into vapor and inhaling? Scary, that.
Oh yeah, the Tesla that ruptured it’s cell storage tank and got wet, exploding into flames in the street… good to know that can’t happen. 
Sorry, but all of it is really irrelevant, the cells we use in our flashlights are potentially very dangerous. That is a fact.
Just about anything in this life that’s worth doing is potentially dangerous…
Some cars may rely on 18650 cells, they have their advantages over big industrial cells. Fact is that these cars have very advanced battery management systems. Far more advanced than any laptop, smartphone, cordless drill, etc.
I know there are hybrids using other cells (pouch, or coffeebag-style)
It comes from working in the industry, if you want a link as an example: BU-308: Availability of Lithium - Battery University
So the leaf has 4 kg of lithium, big deal. As I said: the electrolyte is the dangerous part.
And if you do not even to bother to do some basic research into the technology than I cannot really explain to you or anyone else that the lithium itselt is in its ionic state, not metallic, and the difference it makes. Of course something with a lot of stored energy will release it when damaged badly, that’s why cars with damaged tanks can burn down after a crash. But an undamaged cell will only be affected by water as an coductor. Those things are waterproof.
Not really, do some research. I don’t vape, but it’s obvious that it is nowhere as toxic as the stuff that us smokers put in our lungs.
Before I go on let me ask you how many people in this world use laptops, smartphones etc. with lithium-ion batteries? Billions, and only once in a few years (OK perhaps months) you hear about a catastrophic failure (like some idiot overheating his vape, or some other idiot short-circuiting a battery in his pocket, or really just a manufacturing error).
And yet you only mention cars and flashlights. Why do you not discourage people from using their smartphones or their Laptops, or every other appliance that uses lithium batteries? I hate to be the one new to a forum and pointing out the flaws in your logic.
Truth is: every somewhat modern lithium cell is extremly safe and will only release flames when abused.
and by the way: Love my L6, especially the clear finish. and also the fact that it takes some nice big 26650s
Legitimate information is always appreciated even if it is correcting information from another that you feel is inaccurate but please be respectful of others. This forum is about helping people but not by talking down to them. I’m really not a fan of that particularly in my thread and when directed at someone who has been a very good friend to me.
I just stacked a R100 on top of the two R082s, but the current draw only increased by 0.2A on turbo, am I doing something wrong?
Were the cells at the same voltage each time? Fully charged?
That’s ok JDub, I know I don’t know what I don’t know and think I know, ya know?
I’ve been in this for years, all the information I’ve had available points to an entirely different scenario. I’ve seen flaws in stuff on battery university plenty before, so much so that I seldom read there anymore.
I was going to speak of phones and computers but it would get so convoluted that I deleted it. I used context that had already been pointed at, specifically “we don’t drive flashlights”. So I was trying to keep it real.
I’m not in the Li-ion industry, so what do I know. I just spend thousands on the product and use it daily.
Will, what method are you obtaining your amp reading? Some DMM’s have small leads that won’t show the higher amp draw very accurately, and of course protected cells won’t allow the higher draw. Could be a number of things causing you to not see the jump you’re expecting… does the light appear considerably brighter?
I’m not using my high-amp DMM right now but this one reads up to 8-9A just fine, I have 20AWG 4” leads with banana plugs.
My liitokala cells were fully charged, will test again when I get home with the other DMM, and also ceiling bounce against my modded Jax X6 XHP-50 which produces about the same lumens as the L6 but with twice the throw.