weird battery failure, help me understand

[vapero]

I was running my nemesis in 18490 with an aquilo genesis using rayon. everything was working great then came lunch time, I left my mod there and took another one with me...
3 hours later I decided to take a few vapes of it but I notices that there was a bit of juice on the side of the mod, cleaned it, and tried to fire it and nothing, adjusted the positive contact switch etc, and nothing. tried the rba on another mod and works great, so I checked the batt on my multimeter and 0v, dead empty...

why did this happened?? the wicks and rayon are in perfect shape and not dry, the tank still has the same ml's so I guess it wasn't autofiring,
the battery AW 18490 from a trusted vendor is 1.5 years old but never had an issue, it looks just as new.

I have no idea what happened here

 

[Baditude]

Batteries can be very unpredicable when they vent from thermal runaway. Even though the battery appears normal externally, being that it measures 0 volts indicates it may have vented from an autofiring incident. Odd that the atty doesn't show any signs of this, though. Prolonged over-discharge of a battery causes irreversable chemical and mechanical damage to the guts of the battery. You may be lucky that your Nemesis had adequate venting.

I've had an AW 18350 IMR vent from coming into contact with some coins in a pocket before. It only had contact for less than a minute. I almost instantly felt the heat in my pocket and managed to remove it while it got too hot too hold. I could hear it hissing. No visable signs of a venting, as it vented out the little vent holes in the top cap. The battery was dead when I later tested the voltage on a digital multimeter. I imagine had it continued to have continued contact with the metal coins it may have had a more dramatic venting, but who knows?

IMR batteries can do more than just "vent". Here's a pic of an AW 18490 IMR battery that vented when it came into prolonged contact with something metalic in a bookbag. That's the "guts" of the battery on top. Imagine that happening inside of a metal tube mod without adequate venting. (This did not happen to me in case you were wondering.)

 

[vapero]

but I don't think it autofired, the wicks and juice are intact

the mod was on a wood table that has a strange coating, everytime I put a coffee cup that is a bit hot marks the wood for a few hours and here there is nothing so that means the mod never got hot in any way

 

[Harley]

For a battery 1 1/2 years old I believe it served you well, Sometimes batteries just quit.. For a 10 dollar investment I would say you got your money's worth out of that one.. Have you ever Checked voltage on you batteries with a multi meter when the first come off the charger ?? Once a battery stops taking a full charge it is time to replace it to avoid failure/venting.

When my batteries come off the charger only reading 3.8 volts or less I replace them no matter how old they are. I do not want a bomb in my pocket..