Do you have a firsthand Li-ion accident story?

Ever since I ordered a 2x18650 headlamp on ebay yesterday, I have been reading a lot about the dangers of Li-ion on the Internet. I understand the stated risks of avoiding rapid charge, discharge, and heat buildup. But I don’t see “Hey, I had a Li-ion explode on me” type of firsthand experiences. (Maybe they are not around to tell their stories :-).)

Anyway, to get a sense of how common these incidents are, I thought I’d pose a question to BLF as there seem to be so many heavy duty Li-ion users and experts here.

Do you have firsthand experience of Li-ion battery explode, catch fire, smoke, or do something dangerous? If so, can you elaborate on the situation, including details on the battery type and the equipment it was used with.

I just don’t want my 2x18650 headlamp experience to end up as a Kamikaze mission!

Thank you.

Scariest thing that happened to me was a headlamp I was building had 2 18650s in parallel and when I soldered up the driver it must have somehow shorted it. When I noticed they were heating up I tossed them in a Ammo Can and literally tossed that out the door. When I went to check it a hour later the short had been broken and the batteries were fine. :D

Or another: I had a DRY in my suitcase while flying in a plane. When I unpacked my suitcase my whole bag was warm because it had switched on. When I measured the voltages one was dead (0 volts) and the other two were fine. That could have very easily ended poorly...

None at all, and I use a 2x 18650 light with tenergies. Now alkalines, i’ve had those leak on me all the time, just had to throw out 2 packs of 5 c batteries, they had leaked a ton. I had only bought them last year too, and the expiration date was not met yet.

I had a 14500 blow up in a completely normal everyday charging situation. I still use li-ion cells, but do things significantly different since that incident.

I’m sure that you have read the FBI report:

The NASA report, although very dry, gives some ways to make em blow (and there fore to prevent ’em from blowing):

I now treat multi-cell lights with real caution; charge my batts outside or in a closed room to contain that black crap in case another one goes off, etc. I don’t generally use Cr123 primary or rechargeables, except in my Trustfire mini.

The biggest change, I think, is that my Chinese battery days are over. I use all brand-name bats that can’t be fake because 99% of them are pack pulls. When I use protected cells, they come from reputable sellers like kumabear.

Even before the explosion, I would never strap two 18650s to my head, but other people do without much concern.

I prefer to keep my li-ion batteries next to my genitals :wink: ……Which if you think about it, is where a flashlight spends a good amount of time when walking … If not directly next to that region, my light end-cap/clickie (the part that would blow off like a bullet in a battery incident) spends a LOT of time aimed at that general area. :–0

Remeber quality protected batteries quality charger, no problems

Some of the examples here where user neglegence not the fault of the battery. You don’t often hear the real reason for these incidents, cheap china batteries and user error.

Wow! That’s a scary story. I’m glad you didn’t get hurt.

I am new at this. I ordered my first few 18650 lights in the past week and waiting for them to arrive. The only batteries I have ordered are the Sanyo 2600mAh (the intl-outdoor version and the Xtar 18700 version from Those vendors seem to have a good reputation for non-fake goods here at BLF. My charger is the Xtar Sp2 bought from a US based authorized distributor.

I guess I’ll do my charging outside the house. Most of the accidents appear to be while charging, rather than while using.

Thanks for sharing your story.

Anecdotes don’t count for much with low-probability high-damage situations.

I’ve had one RCR2 fail to charge after being overdischarged; I tossed it in the (metal) storage box.
A few weeks later I noticed it had vented at some time; there was nothing flammable near it, no other battery in the box, no carbonization or burn marks — only noticed brown stains outside each of the four vent holes around the positive terminal.

But to know what the issues are, don’t listen to me and take my experience as a measure of risk.
I’m some guy you don’t know on the Internet.


Here’s one of several current articles:
That’s Fire Protection Engineering Magazine.

But a year from now, you’ll find something different — note how much is not known or documented about what’s being used in these batteries —- and what you get next week likely will not be the same as what you got last week.

There’s always going to be someone who finds a cheaper way of making them.

A good multimeter like Fluke or Agilent will definitely reduce your chances of accidents. And don’t charge your battery overnight without a timer control. If you think it will be fully charged in 4 hours at that initial voltage based on past experience, set the timer to be 4 hours before going to bed, only charge over night in situation where you will need the batteries fully charged next morning.

Accidents will still happens, but chances are very very low. I think I need to improve safety further as I am getting more and more batteries.

Great article, Hank. I hadn’t seen that before. Thanks for posting it.

I think many many many people can buy many cheesy Chinese batteries and not pay attention to safety protocol and never have a problem. Like any accident, I think much of it is being in wrong place at the wrong time with the wrong battery, which is what happened to me. Just be aware that there is a tiny chance of a big problem and do everything to avoid it and you’ll be fine. And yes, a DMM is a lifesaver (literally) with li-ions.

I have never read: “Man’s legs blown off by laptop battery malfunction” or “Handless web designer blames injuries on li-ion batteries.” I think real explosions with brand-namers are extremely rare. But by brand-namers, I do NOT mean *fire batteries.

IMHO (a nobody on the internet), if you stick with well-known battery manufacturers, you should be fine — judging by brand-name manufacturers’, safety records. But the root problem is — search BLF — that labels for just about ANY brand-name li-ion cell are readily available on the interweb, so buying brand-name by itself isn’t good enough. Any cell from China (brand name or not), can be a dangerous fake. And — even if the cell is protected — how do I know the protection circuit will even work? Those are the tough problems to get past, for me anyway. At some point, you just have to trust a vendor and keep your fingers crossed.

And read BLF posts. Members here really keep a close tab on good and bad vendors and good-bad batteries.

I was just taking some IMR cells out of a pack the other day and one was giving me real grief so when I twisted it really hard the tab ripped though the shrink wrap and gave a nice little spark show; it still didn't come off so I had to give it another yank and momentary shorted it again with my pliers :O. The cell's fine though, still need to clean up the contacts, remove the little pinch welds.

Another time I was ripping out cell's (Some old sanyos) from a laptop pack and got some of the paper I didn't see stuck in the tabs, burned pretty fast and smoked; I was worried for a bit that I had shorted the cell and it was starting to vent :8). All was fine though.

I had a friend blow up a Nimh tab by twisting the connectors together (Accidentally) and then he thew it in the river :((; Still could have used it J). Shorted my NiCD pack a few times while soldering (on the floor, over a magazine freehand in winter; don't ask why). I saw a nasty twisted lipo sitting in a display case, the thing was still functioning after being outside nearly a year (Though horribly maimed and disfigured, not real safe either).

Had a few NIMH AA's hit the dust, the worst of which sat in car in up to 110f weather for about 4-5 years. Bit of acid here and there but cleans up pretty easily.

I guess I haven't had all that bad of experiences in that regard, but someday it might catch up to me; I guess, but who needs to worry when your safe!? :steve:

That last question was rhetorical, don't answer it ;v

I think it's pretty rare and you can decrease your odds much more dramatically by not running 2x18650,buying only quality cells,heeding good advice from blf ,checking your batteries with a meter,being present while charging etc . I use LMR in multiple cell configurations .

6000 members who play with batteries daily .. and only a handful have had incidents ...thankfully none serious .

I think your odds are really good you'll have absolutely no problem.

But do the right things to keep your odds up

The Crelant 7G9 thrower is often compared to ThruNite N31. Reviews elsewhere suggest that it is a lower priced inferior contender. First impression is good but I later found with some rooms to approve.

Two damaged conical coil spring due to my reckless manner once pressed fitted into their respective brass cups on negative pole were pulled out for your appreciation. I had shorted the all three 18650s after tightening up the head and tail halves.

This pic shows the brass cups one empty (left), one with survived undamaged (bottom) and one with a replacement spring (right).

Failed to turn the torch on, surprised and scared, I opened it apart just finding two of the total 3 cells were sitting lower than the remaining one. This demonstrative pic shows the highest one resting on the replacement spring, the slight raised out one on the undamaged spring and the recessed one on a damaged one in up side down manner for full seating . I recalled at the same moment felt a localised warm segment down the tail, likely where the negative springs are. No fumes, no smoke, no smell, the damaged was done unnoticed.

I made a mistake to place an oversize (for covering 4 cell tops) SS disc trying to covered 3 cells instead. The resulting contact shorts the cells with current flowing unhindered. I had read from previous previews that the gold plating on the positive pole PCB woukd be ground away easily and tried my old trick to protect the positive contact.

Perhaps to save metal cutting cost, the 3x18650 battery compartment provides three nealy full length and circular voids (i.e. a little shorter than 65mm). For improvement and following design of other brands, when fully closed, a wider gap between the positive pole plate and the battery tubes top facing should be appreciated.

I failed to recogise the trouble and closing again but w/o the disc. Hurt locked after seeing the beam coming out and every aspects was functioning (shortened springs are obviously not fully seated onto the brass cups). I did a dentist’s job and manage to pull out the dwarf conic springs w/o damage. A removable tail cap is available in newer batch according to reviewers.

Under the condition that the springs are fully compessed inside the brass cup, the torsional shearing stresses should be very high. I wondered what happening to the the springs when meeting with so high a temperature induced by the wild current so that the rotational yielding strength reached and exceeded with permanent settlement. The gold plating evaporised and the bare metal blackened. It is miraclous to be able to save a good torch and witnessing such a drastic physical change.

Can I say I prevented a future accident? One of my Ultrafire 18650 that was free gift when I purchased torch light is getting hot when charging. Found that it is actually rusted on positive pole this morning. Made a video below.

And regarding the batteries in parallel configuration, i always think that it is quite dangerous. It can happen that 2 cells are discharging and 1 cell is not making contact, and the 2 cells are discharged until let’s say 3.0V, and the fresh cell decided to make contact, it will be 4.2V charging on the depleted cells. I prefer series connection with battery holder though a little slow putting batteries in them.