A few weeks ago I purchased the A8 / TF5000 / TF TR-005 charger combo deal. This evening I used the charger for the first (and last) time to charge a King Kong ICR26650E cell. I had it plugged in a wall outlet in plain view from a chair in the family room. About an hour later, my wife (who can smell a mouse fart) commented that there was a funny electrical smell as she walked by the charger. Sure enough, I checked it and both the battery and the charger were hot and giving off an ozone/burning plastic smell. This one's going in the garbage bin.
New chargers can smell - Being new and all !
And if poorly ventilated , yes they can warm up … I keep my Trustfire TR003 on its side , so that heat can not build up , electronics need ventilation …
I also have it on the floor near me , where air moves all the time . Charging some 4 x 18650 can warm it up , but just a little common sense keeps it at safe levels [ warmth ] …
I charged some 12 batteries yesterday , and my TR003 has become my go to charger …
Yes - dont trust any charger , dont trust any battery … Always check for abnormalities …
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1/ I always check Battery voltage before charging
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2/ Always watch the charger at the beginning for anything strange
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Also get in the habit of checking your batteries for degradation or resistance to charging [ yes its easy to forget or get lazy ]
Li-ion demands some respect , and cudo’s to those who prefer AA , there are some nice AA lights out there to chose from .
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Now I have to start charging more batteries , only about 30 or 40 more to go
+1 for AAs
“Responders to fires involving lithium-ion battery packs have often described a series of re-ignition events. Typically, responders report they used a fire extinguisher on a battery pack fire, thought they had extinguished the fire, and then observed the fire re-ignite as an additional cell vented.”
Funny how it’s always Ultrafire exploding.
I always measure the internal resistance to get an idea of whether a battery will deliver a decent current. It is also a fair guide of whether they are safe.
I don’t know if I was using the same Ultrafire battery as above (the label said protected, but they were bare cells, no pcb), but check the comparative internal resistance:
Internal Resistance mΩ
Ultrafire 14500 1200mAh protected? 905
GTL 14500 2000mAh 179
DLG 14500 750mAh 113
AW IMR 600mAh 64
FJD 800mAh 283
Marsfire 930mAh 150
AW 750mAh protected 168
EagleTac 750mAh protected 141
Yezl 900mAh protected 172
Trustfire 900mAh protected 151
Efest IMR 700mAh 43
Nice. :)
That’s quite a bad-ass explosion.
I am very wary about explosions, since an explosion of a plastic pressurised container (those pump sprayers for plants/gardening) did fracture the middle phalanx of my right hand ring finger 3 months ago, costed me 11k in total.
But i was lucky, coz it did explode near my hips ala dick area, but the sharpnel for one reason or another decides to fly forwards ie away from me. Fish…till today i still thank my lucky stars.
Cut my 3 fingers, lost quite a bit of blood, enough to make me faint for a few seconds prob due to low blood pressure.
I don’t know what happened in your case bro…. seems like it satisfied the 2 conditions….(1) Protected PCB failed to cut over-voltage (2) The TR-007 charger failed to cut over-voltage. Can Li-Co explode below 4.20V? Not sure…. I have that charger of yours, exactly the same except the colour. It does cut nicely for all my unprotected cells.
Usually cells explode at about 4.27/4.28V…some even say as much as low 4.3x volts.
@2100: Woah, never knew these things could explode. I thought that stuff was soft enough to just crack open a bit and release the pressure..
Depends on the cause !
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If the fault is in the charger [ a short or something ] the the potential is there at any voltage … …
If its the battery itself , two things to watch for , heat and over voltage … …
So if the charger fails to terminate , or if the battery suddenly resists charging at a lower voltage [ still a decent charge current ]
Under normal conditions , the charger should be trickle charging at such a low level that even if it does not terminate , the battery and charger should be in a state of stalemate , or a situation where it would take hours and hours to charge another 100mAh …
So again , the chicken or the egg ?
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Cells exploding @ 4.27 4.28v … I hate to say this , but that is dangerously close to 4.2v and little in the way of safety margin ! [ and Im not sure its the case ]
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What is certain , is you need a MM to monitor your batteries , otherwise your going it blind . You need to know your batteries , there usual charge rate [ voltages on termination - voltage sag after say 60 minutes of rest ] There should be a sticky on every flashlight forum ! , in fact I will post one on my web now that I think of it !
I store all my cells in a surplus ammo box for belted 20mmx139 Oerlikon autocannon cartridges. A lot beefier (9kilograms/ 19.8lbs, empty! ) compared to the average .223 NATO ammo box. Now, I am wondering if that stout 20mm box could handle the pressure of an exploding 18650… and still, how to vent/ release all the pressure once it has blown? It’d probably shoot everything out of the tiny hole you’d have to drill for the power cord, to power the charger, anyways. Weak spot IMHO.
What is the price for a stick of dynamite, these days? Eventually, cheap XXX-Fire Li-Ion cells might become a cost-effective alternative 
Anyways, thanks a lot for the essay!
Now I know I was right to charge my solarforce 16350s in the garden only, covered by an old 40lbs sand stone feeding through turned upside-down. But now, I am a wee wit worried about my protected Trustfire 18650s, though. They seemed to be decent…? One will never know. Might hold up to a hundred charges, might eventually disintegrate within milliseconds the next time I put it in my WP2. Am I worrying too much?
The PCB are designed to protect from common electrical faults like over-current or under-voltage, not everything under the sun. If these aren’t the culprit, seems likely this cell failed simply due to physical/chemical manufacturing defects.
It’s like claiming not to trust in seatbelts anymore because some guy burned to death in his car.
@ubehebe. Any idea how long the batt had been charging before it exploded? What the starting v was? A couple weeks ago I was charging a crapfire & 30 min in I checked with my hand & it was to hot to touch. It could have been moments from exploding yikes.
Keith
The OP did say his cell is protected, but did not mention any dead short testing.
For me i test each and every expensive and cheaper TF Flames with a dead short on the DMM. It should just jump a bit on the meter. In fact I still do that occasionally even though i am not getting new cells.
That is because my SR3800 driver (the Sky Ray 3800 original triple XM-L) did present to me a dead short.
For charging/overcharging, i do DMM each and every cell very regularly, it’s just a habit coz I have many multi-cell lights. Max I get is 4.230V-4.235V should I leave it there for too long. (sometimes it goes back into charging for 3 secs and terminates….but if you do this for too long then obviously it slowly inches up, till maxes out at 4.23V). Actually i charge at the yard area already, which is like semi-outdoors + nicely ventilated. Actually nearly 4.3V is extremely cautious/conservative but for our use we can’t be too cautious (it’s BLF here), there are some vids on youtube showing higher voltages.
It seems to me that a temp sensor that will shut down the charger if the temp of the cells gets too high is a good idea.
That could be in the charger or installed in the power line between charger and wall plug.
Also, don’t some cells already have a protection circuit that does that built into the battery? I mean separate from the over/under charge and current flow limiter components?
Just have to use decent cells and trust the systems in place.
Even TF Flames nowadays seem like a russian roulette.
For my TF Flames, well at least I did randomly pick some and test the capacity. I think that’s a good idea to do that.
Bite the bullet and spend 30 bucks for an entry level hobby charger, not that expensive anyway and it’s great fun.
Unfortunately most of the notebook power adapters are like over 18V, so need something to take that input voltage if you don’t want to shell out money for a power adapter. (assuming you have access to many unused/unwated notebook power adapters, have lots in my office :D)
SLA and NiMH tells you by raising the temperature when they are charged too high a current or overcharged. Unfortunately Li Co does not do that.
Check out the youtube vids, they don’t overheat for nuts and then they vent.
PET/Polycarbonate. Mine was like those Nalgene bottles….transparent.
Definitely NOT FUN. Rip open and release pressure….wait long long. 
I’ve got some explosive experience. If you’re wanting to build a charging box build it from wood. A 5/8” or 3/4” plywood floor and walls should be plenty. Make the box about 1’ cube with no cover this will contain the explosion and vent the blast upwards. Yes you’ll have a mess to vacuum up but no dangerous shrapnel from an attempted contained explosion. Box covers and the likes become projectiles. All explosions have to go somewhere with the open box it vents to the ceiling. Nice thing about wood is that fragments like to stick in the wood instead of bouncing off like metal or plastic containers. If you’re trying to cover an explosion use IV or water filled Ziplock freezer bags, but thats another story.
>>>>>>@ubehebe. Any idea how long the batt had been charging before it exploded? What the starting v was?
About 30 minutes. But it was cool as a cucumber when I felt it. There was another gray crapfire 14500 in the other charger slot.
No, I did not check starting voltage. That was in my salad days. I ALWAYS do now because I use all unprotected cells, so I’m always monitoring them to get a better idea of when to pull the battery before it drains too much.
When I first started with the li-ion batteries, I really didn’t pay much attention to charging. These bateries and chargers don’t come with any instruction manuals :-). I was vaguely aware that it could explode, but like everyone, thought it was rare and would happen to someone else. But surprise surprise! KABOOM!!!
>>>>>a charging box build it from wood. A 5/8” or 3/4” plywood floor and walls should be plenty.
>>>>>>Make the box about 1’ cube with no cover
Now that sounds like a good idea! All this stuff about sealed boxes. Like I said, I myself won’t be putting a a stick of dynamite in a sealed ammo box inside my house to see how well that controls the explosion. I wouldn’t put explosives in a sealed anything to control it. Of course, the box lid may pop off from the explosion and vent some of the force. But it’s like a battery PCB, I wouldn’t trust it to actually do that.
I’ll just skip all the contraptions and charge ’em outside, away from the house. If anything happens, no appreciable damage except to the charger and battery, PLUS minimal clean up.
I can’t stress enough, you DO NOT want to clean up that black gooey stuff. It is NASTY.