I found the 16340 dead in my locked out Jaxmnve M3. The tube had signs of leakage inside. Anyone know what causes a cell to self destruct? It was a couple years old and only charged a few times.
Maybe parasitic drain?
When my Jaxmanve was “ok”, I used to leave the cell inside, and after sometime it was drained. Never leaked. But maybe that can cause progressive damage…
Was it a good cell or one of those “blue” cheappo cells?
BTW, on the OTR M3 Pro, I started using a piece of plastic on the - pole to avoid draining.
It was the blue one that came with it. I guess locking it out was not 100% effective. I am replacing it with a protected cell. Do you think this will do the trick?
Well, I cannot be sure if the “self destruction” was due to that, but as for the parasitic drain it will surely avoid it.
Unless that is a light you use frequently and in which putting the plastic in and out is troublesome, I would say put it in. A protected cell will be more robust of course, but it won’t “hurt” having that extra protection in it 
Some lights with e-switch I use that strategy to avoid drain if not used for a while. Others, I just leave them empty
Not a bad idea. It does not get used much.
I had a Sanyo white Eneloop AA leak that wasn’t used much and a Sony VTC6 iirc leaked while charging.
A protected cell has a little circuit board added that uses both passive and active components, any of which could fail and be a source of drainage even when the FL is locked out. The protection circuit is always ON so it is pulling a small amount of current. Maybe that is the case with the “blue” cell?
The blue cell was not protected. Seems ironic a protected cell will self discharge when advertised to be protected from over discharge and overcharge along with short circuit protection.
yes that does seem odd. Here is a schematic for a little single cell protection ic commonly used in low cost bms and protection circuits. It has to draw at least a tiny amount of current to keep the FETs on. In an UV condition it will turn off the FETs, but does it turn itself OFF to stop all current draw…? Have to check the datasheet or somebodies test data.
i tend to take stuff apart when it fails to determine the culprit. Maybe the inside of the blue cell is not what it seems. Some folks have found smaller cells inside the cylinder, maybe even a different chemistry. The only leakage path would normally be at the positive end thru the vent holes if the pressure valve was triggered to open?
I’ve had KeepPower IMR18350 cells leak. It appeared to happen after heavy use and accompanying heat.
Not all cells need protection circuits. Only LiCo aka LiCoO2 aka ICR cells will have protection circuits because that is the only chemistry that when brought below 2.5V and placed back on a charger might explode or cause a fire. LiMn aka LiMn2O4 aka IMR cells never have protection circuits because they can tolerate going below 2.5V and recharging, at a hit to their capacity. LiNiMn aka LiNiMnCoO2 aka INR also won’t have protection circuits for the same reason.
Many new users seem to incorrectly believe protection circuits make the cells and the user safer, but IMO that is putting a lot of faith in a protection circuit, what I would call a false sense of security. Always be aware of the state of charge of your cells.
I always mechanically lock out lights I don’t carry. Twisty lights are usually able to lock out properly (IMHO). If a light with a clicky switch has bad ano or no ano (like Cu, SS, and Ti) I store it with a plastic disc between the back of the battery and the tail spring.
Most lights that I use on a typically daily basis have cells in ’em.
Those that are boxed up (box-queens) never have any cells in ’em, not even tailcap locked out or with an insulating disc, etc. (unless one got by me).
Those that I don’t use daily but are not boxed up, rarely have cells in ’em unless I’m likely to use ’em at some point, eg, my Cometa. But even that, with my well-diffused Tacklife moose often taking its place, I might even pull its 26650 to be safe.
Point being I don’t trust cells left in any lights, certainly not alkaleaks of any kind, but not even NiMH nor Li-ion.
And when I had a cell drop dead in my PB2C, and still ain’t sure if it’s the cell itself, the protection thingy, or the PB2C, that’s to blame, it makes me all the more skittish to leave cells in lights that might be forgotten about for a short or loooong time.
Wow, an RCR that leaked? Unusual.
parasitic drains can overdischarge, obviously, but i never heard of an actual leak
wle
Well, put a new cell into the Jaxmnve M3 today and the light is stuck on. The switch does nothing. Which came first, the dead cell or the stuck on UI. I thought it had been locked out when it went bad but I could be wrong. Could the leakage have ruined the driver? Everything looks pressed in. Has anyone removed the driver in one of these ting lights? Anyone care to speculate as to what may have happened or how to take it apart?
Bingo. Had a hunch that the battery leakage may have shorted something under the driver so I blew compressed air into the switch and charge holes. Seems to have solved the problem.
Well, the light started turning on by itself again so I went in. Unsoldered the LED wires and pushed the driver out with a paperclip through the holes. Really happy it came out easily. One screw holding the USB charge jack. I saw what could be goo shorting the positive lead to the body of the pill. Scraped it out and attempted to reassemble the tiny parts. One lead to the USB broke loose and this is where I went down hill. My eyes don’t focus so well even with powerful readers. Also I don’t have anything to hold the part for me while I solder. Kept getting a cold solder so I kept trying until the land tore off the board. Now I can’t see where it originates to bridge a repair.
This was a $10 dollar light but it was cool. Now I have a new 16340 cell and no light for it. Can anyone recommend another cheapo 16340 light with USB charging please? The closest I could find was the Wowtac W1 for $20. Nice light but more than I care to spend for what I consider a novelty light.
I would suggest On The Road flashlights (311, M3, i3), as I am a fan and they are really well built.
You can also look top the Trustfire MC series, although that UI… 
And you can try a similar one :
https://www.aliexpress.com/item/4000020356705.html
https://www.aliexpress.com/item/4001071441110.html
I believe this has a different UI, probably improved since it was a Jaxmnve
Hownahell you even pronounce “jaxmnve”?
I have no idea, but the word is worth plenty of Scrabble points! 