Not with a bang but a whimper...

[MisterMike]

The subject line doesn't 100% accurately portray what just happened to me, however I like both cultural references and T. S. Eliot, so pthhthbhbphtbpht.

Anyway, that over and done with, I was busy setting up my DID with a new coil today, taking all necessary precautions to avoid shorts and whatnot, and I get things to a point where they're stable. The resistance doesn't fluctuate, I'm not getting hotspots, and the coils are lighting evenly. All good? All good.

I start vaping away on my Lavatube, and I hear a sort of snap, as though someone had opened a Christmas cracker close by.

Next thing I know, my LT's not responding. No power. Uh-oh.

I pull out the battery, and check the power with my multimeter. 3.18. 3.17. 3.15. 3.14. 3.13, all the way down to 2.87 or so, while I'm watching. This can't be good. Check the other battery. Voltage is steady.

Out comes the sharpie. Big X on the bad battery, until I can get it to a recycler.

Now, this battery (I'm assuming. Didn't mark it, though I probably should have) has been discharging faster than the other one lately, too. I'm wondering if it just finally decided to give up the ghost, or if there was a possible micro-short somewhere in my new coil setup that I missed.

Anyway, could've been worse. Could've vented hot gases all over the place. Could've *not* vented and exploded. As it was, just a small "pop" signaled this battery's expiry.

For the record, it was one of the non-AW IMR 18650s that came with my Lavatube way back when. There are no tears in the plastic jacket, and everything looks the way it did when I got it.

Good thing I still have backups.

 

[Dusty_D]

Glad to see that you're safe. You're lucky it was a whimper and not a bang. Get rid of it's partner too..

 

[MisterMike]

Yeah, I'm pretty leery about the other battery, too. It seems to work a lot better, but do I want to take that chance?

My DID is vaping just fine on my Twist, even though it looks a little silly.

 

[tygertyger]

I will consider myself forewarned. I just received a slightly broken-in Lambo from a kind, generous veteran.... and I need to acquire a spare 18650 and charger for it. I'm not proficient enough to wind my own coils though yet, so I'll probably be using simpler attys on it for now, but it's always good to be reminded to be careful.

Glad to hear there was no harm to you or equipment!

 

[Mindfield]

Good thing the failure wasn't catastrophic. I never trusted those nondescript batteries that came with the LT, but I never used them because they just weren't very good. But it could have been a lot worse, so I'm glad it just decided to whimper.

 

[MisterMike]

Good thing the failure wasn't catastrophic. I never trusted those nondescript batteries that came with the LT, but I never used them because they just weren't very good. But it could have been a lot worse, so I'm glad it just decided to whimper.

Thanks, everyone, for your various expressions of relief at my continued well-being.

At first I thought maybe a capacitor or something had blown in the LT, 'cos I didn't think a battery just made that kind of sound when it failed. I would have thought it would either hiss or whistle if it were forcefully venting hot gas.

That reminds me, while we're on the topic of catastrophic battery failure, of a question. I'm assuming a thermal runaway happens after a critical temperature has been reached. If this is so, are hot springs designed to collapse before the battery reaches that temperature, thus saving your mod and your battery? It'd be kind of pointless, otherwise, I would think.

I just took a look at a couple of actual AWs I have lying around--14500s, but they should be pretty similar, construction-wise--because something just struck me as odd. The LT batteries were flat-topped, with kind of a depression running around the positive end, about an eighth of an inch or so from the top. The AWs have nipple-tops, and are the same diameter all the way up. This got me thinking: Is there some kind of fuse mounted on the battery? Because that would explain everything at a stroke.

Being the kind of person who rushes in where certain supernatural beings may fear to tread (I'm on a referential rampage today!), I decided to carefully slice and peel away the wrapper near the top of my dead IMR and have a peek. Turns out, the metal shell is one solid piece (far as I can see anyway) that jogs in where the depression shows on the wrapper. I didn't want to do any further exploration, so I just left it at that. Eh. Was worth a shot.

(Disclaimer: Please do not attempt to open LiMn batteries. I am a trained professional landscape designer on a closed course, and I informed myself of the potential hazards involved in such an undertaking, and took appropriate precautions. Yeah, it was just a piece of shrink-wrap, but you never know. Safety first, people.)

 

[chagrin]

That reminds me, while we're on the topic of catastrophic battery failure, of a question. I'm assuming a thermal runaway happens after a critical temperature has been reached. If this is so, are hot springs designed to collapse before the battery reaches that temperature, thus saving your mod and your battery? It'd be kind of pointless, otherwise, I would think.

I don't know out of experience, but I've read numerous times that the hot spring is a safety feature that should collapse with too much heat, breaking the connection.

 

[MisterMike]

I don't know out of experience, but I've read numerous times that the hot spring is a safety feature that should collapse with too much heat, breaking the connection.

Yeah. I'm pretty sure that's the idea, however I've also heard that catastrophic battery failure is a chain reaction that you can't stop once started, so I would assume there's a critical temperature that the hot spring will prevent the battery from reaching. I dunno. It's a curiosity thing, more than anything. I like to know how things work.

 

[Darkside77]

It is very rare to see a catastrophic battery failure in a non stacked PV. It can happen but i doubt any of us will ever see it unless using unprotected Li-Ion batteries and allowing them to go into a under voltage state.