CR123 exploded!

[g36pilot]

If I can follow you, do you mean that it might be possible that the tailcap was tightened for constant xenon-light? I can assure that this wasn't the case.

I wouldn't dismiss this possibility so quickly. It would be VERY easy to miss LED tail cap being in the incan "Continuous ON" position with batteries low enough that they don't activate the incandescent lamp.

The only indication of this scenario would be that NO lamps illuminate w/switch activation as the switch is already beyond the LED "Continuous ON" position. Incidentally this indication is the same as when the tail cap is locked out or dead/no batts are installed. Not a good situation as the circuit is complete and easily mistaken for a "safe" position.

The only low batt "safe" indication with this rig would be to verify the LEDs activate then back off the LED tail cap until depressing the switch will not activate the LEDs. This is similar to a LOTC (Lock Out Tail Cap) safe position.

The above is my opinion only and not intended as critique of any sort. Just sounding out possibilities. Glad no one was injured.

G36pilot

 

[The-David]

Batterystation cells suck :thumbsdow

+1 never agean

 

[IsaacHayes]

A Fenix L2D-CE would be a nice light for him. Lot's of lumens from a LED that can run on safe NiMH cells Some eneloops would be nice so he wouldn't have to worry about self discharge.

Glad no one was hurt. Looks like it vented perhaps with flame but didn't get too hot or melt down totally and get the other cell going too. If you keep the light be sure to take it apart and CLEAN it very well to get out all the toxic chemical residue. Take it apart as much as you can.

 

[mdocod]

I have not heard of any event where a single cell light has ever exploded... single cells lights are considered safe to do "deep" discharges with on lithium cells because there is no imbalance of cells...

I'm pretty sure that the conclusion was that many lithium cells come from the factory with unmatched capacity, but it is near impossible to measure this imbalance because just about any cell above ~40% true capacity will measure about the same voltage and voltage under a load.... flash amps seem to be a little more relevant, however such a test isn't necessarily considered safe to do either...
When combining cells that are mismatched, one cell depletes, and the other cell actually tries to reverse charge the depleted cell whenever the circuit is "on"...


I am going say, with 78.537% confidence... that what happened in the wolf-eyes is as follows.

1. one of the cells came from the factory perfect, 100% true capacity.
2. the other cell came from the factory with somewhere between 40 and 60% true capacity.
3. The light was used until the incan bulb would no longer light up.
4. At this point, one cell was DEAD and the other still had somewhere between 40-60% capacity remaining... but since the voltage of a single cell isn't enough to hardly begin to light up a 6V bulb, it appeared to be mostly dead... but this is why it probably still had a lot of "light up the LED" life left in it....
5. The user did not take into consideration 1-5 and was unaware of the problems that this condition leads to with lithium photo batteries.
6. POOF

 

[mdocod]

the solution:

replace the 2xCR123 with a single 17670 or 18650 and replace the lamp with a 3.7V. rechargable, single protected cell... much less room for problems and much cheaper to operate in the long run.

 

[Radio]

Dupe

 

[Radio]

It HAS happened to Duracells. I think its safe to say it has happened with every brand of cells out there. The only reason I can see for the increased number of incidents with BS cells is because the majority of us use them and report the failures. How many non-CPF people do you think are out there that have had failures with other brand name cells that we dont hear about? Im sure there are several BS has gone to great lenghts to insure their cells are safe and has even volunteered thier time to test every cell before it goes out the door.

A link would help. Never any mention on the forum of a Duracell exploding.

 

[David_Campen]

I wonder when these cells were purchased - before or after BS began ZTS testing their 123 cells?

 

[ghostguy6]

A link would help. Never any mention on the forum of a Duracell exploding.

Happened to me before I became a member here, I might be able to find some pictures on my old hard drive, Ill try to find them tonight when I get home.

 

[DocArnie]

I wonder when these cells were purchased - before or after BS began ZTS testing their 123 cells?

I bought them july 2005. I can't find a date on the batteries.


I can only speak for this specific tailcap. You couldn't screw it in the wrong direction accidentally. The change from LED- to xenon-mode was close to the tightest postion. I'm still pretty sure it was no user error. I have no problem blaming my brother if he did something wrong - I do it all the time! But in this case I think he's innocent.

 

[elgarak]

They print the manufacturer month and year (I think) on the bottom (negative electrode). But it rubs off easily, especially with twisties .

 

[Art Vandelay]

Good point. Also, plenty of those old posts were from people who were intentionally making the batteries explode. If I experimenting on batteries like this I would probably use the cheapest batteries I could find too. Don't try this at home folks, but they were testing to see what would make the batteries explode. The idea was if you learn why one explodes, you will learn how to prevent one from exploding.

It has happened to all brands. That most reported incidents are BS cells is just because BS has a killer deal, and is the most common brand.

I am not aware of ANY incident where cells just so exploded. All incidents I know of have happened IN lights (or just after removal from them), not in storage, and in all cases the switch status was undetermined (my gut tells me they were left ON for extended periods, either by faulty equipment or sloppy operators).

Considering that, given that the batteries were too low to fire the Incan, there is no outside indicator to determine between incan off or on (the LEDs turn off in BOTH cases), except for the operator making sure he turns the tailcap the right way. I would file this incident under sloppy operator -- the batteries, rundown, should not have been left in the light. (If the incident has happened as described, that is.)

 

[mdocod]

like I said, I think the error was not that the xenon was left on(it probably wasn't)... it was that the batteries should have been tossed when the xenon stopped working, and the LEDs still worked fine.... Most normal users would not even consider the underlying issues with this situation... so technically speaking there was no real user error beyond not understanding the situation... In the future, when things get dim on the xenon, it's time to dispose of the cells..

 

[LuxLuthor]

[Sarcasm]Yeah, this is obviously nothing more than someone bringing a can of gasoline and a lighter into the room. Nothing to worry about here either. All these people bringing up bogus dangers about Lithium batteries catching fire and exploding. It's all obviously faked and blown out of proportion.[/Sarcasm]

ROFL !

 

[carrot]

Be careful with those vented cells...

Anyway, please reference this thread, written by the legendary NewBie.

http://candlepowerforums.com/vb/showthread.php?t=124776

 

[cy]

when Newbie was doing lithium cell testing... it became apparent, light had to be left on with cells in a mismatch condition. leading to stronger cell reverse charging weaker cell... leading to explosions.

also failure mode mostly occurred in Chinese mfg cells. failure events almost never occurred with surefire cells.

 

[David_Campen]

[Sarcasm]Yeah, this is obviously nothing more than someone bringing a can of gasoline and a lighter into the room. Nothing to worry about here either. All these people bringing up bogus dangers about Lithium batteries catching fire and exploding. It's all obviously faked and blown out of proportion.[/Sarcasm]

ROFL !

So Lux, I get it that you are in love with yourself but do you ever actually have anything worthwhile to say?

 

[LED61]

So when the battery vented with flame, what did you guys do about the smoke and smell afterwards ?

 

[bridgman]

Kudos for wearing gloves when picking up the exploded batteries.

These posts are a great wake-up call as long as we don't go overboard. Anything that stores a lot of power is dangerous, and the more power it stores the more dangerous it can be.

I'm actually with LuxLuthor on this -- I think the CPF folks "can handle the truth" (heck, many of them already know the truth, with is statistically unlikely these days) so a couple of prominent stickie threads could make a big difference for us new people. It's not a question of scaring people away, just making sure we offer a no-BS summary of the risks and how to avoid them.

 

[Canuke]

when Newbie was doing lithium cell testing... it became apparent, light had to be left on with cells in a mismatch condition. leading to stronger cell reverse charging weaker cell... leading to explosions.

This is probably in the "well, duh!" department, but it is worth noting that as an incandescent bulb dims, it's resistance goes down, to the point that if it is completely out, it is nearly a dead short for whatever's left in the cells.

When incans were all we had, even a mismatched pair would likely get tossed once the bulb was sufficiently dim to be useless, and that would usually happen well before the weak cell reversed. That might explain the observed dropouts noted prior to previous explosions; when the weak cell dies, the bulb becomes a dead short right there, and the strong cell has free rein to reverse it. If the switch is left on, that short is still present -- tick, tick, tick goes the bomb.

The LED's change that equation; they get MORE efficient as the cells weaken, producing light even at half rated voltage. I wonder whether the mismatch in this case was a much smaller one, where the decline in output would have seen the cells tossed in an all-incan application, well before reversal occurred... but in this case it didn't because of the LED's. I bet the weak one here reversed when the incan went out (shorted), and the subsequent "drainings" with the LED's pushed it over the edge, bit by bit.

I suspect that weak cells, once reversed, do not always blow, but are much more likely to do so. It could happen within minutes, hours, days or weeks of reversal, or never. The longer they are subjected to reverse current, or just sit around in this reversed state, the more likely they will blow.

If I'm right, the moral of the story is twofold:

1. If multi-cell CR123 incan lights show any sort of sudden drop in brightness, SHUT IT OFF and dispose of the cells, someplace safe.

2. Do Not Suck CR123's Dry. Abandon the practice of bottoming them out in an LED light. Alternatively, test/ZTS the used pair again *before* you put them into the LED light, make sure they are still close.