Samsung ICR18650-30B leaked

Stored too long? Apparently one of my Samsung ICR18650-30B leaked (top), but luckily the leak was inside the plastic casing of the cell itself. The bottom cell is fine.

Only used in 1×18650 lights before, and then I put it into storage in those plastic cases.

Not sure if it’s a leak though, but it seems like watery inside with brown liquid.
But it has never been into water before.

What to do with this now?

Comes from FastTech, about 1.5 years ago.

The other cell labelled “1” measures 3.78V on my multimeter.

Li-Ion cells leak?

Wow man, I've never seen that happen before. I regularly check the voltage on all my cells to make sure they are not discharging significantly on their own. BTW, I keep all my unused cells at approximately 3.8 volts. Have you been checking the voltage your stored cells?

Where did it come from?

What use (and abuse?) have it been through?

Comes from FastTech, about 1.5 years ago.

Only used in 1x18650 lights before, and then I took it out for storage.

Never been into water before.

The other cell measures 3.78V, so should be fine I guess.

Updated with more pictures

I have no answers, and probably won't have any, but would you satisfy my curiosity and peel off the wrapper and take more pictures?

Rod Serling can make a Twilight Zone out of this one..... (BTW, he's been dead for almost 40 years)

Where did you store these? Could it have happened that it has got wet through humid air or so? Which voltage does the leaked cell have?

Also the liquid was a solvent for the serial number…is the label water solvent? If not it is a hint for another liquid.
Anyway in the name of science you have to put some gloves on and cut the shrink tube open for further investigation.

I have seen very old cells rust a pinhole in the case aand leak like this.

The leaked cell has no more voltage.

I stored them in those transparent case in my cupboard. Shouldn’t be the humid air I suppose, because all other cells are fine.

The label of “Samsung…” is inside the outer wrapper, so all the leaked liquid stayed inside.

Interesting. What voltage was it when you stored it? Did you make any periodic checks on it?

I think I’ve seen another thread on BLF here about a well-known member who had a battery pop at his workbench. I just remember somewhat poorly lit photos, and that he found brown goo leaking off the shelf that the batteries were on.

My experiences with these is that if I smell bubblegum, throw it outside.

Could it be that the protection circuit was faulty, and slowly discharged this cell all the way to 0v? Is it the cell itself measuring 0V, or the potential across cell and protection circuit measuring 0v?

OH yeah venting Li Ion are capable of that

Not sure how they leak…they are in a sealed pressurized container (thus the popping/venting ability [build up to much heat in a sealed container and kablammo])…is it possible sure, but odd to have them rupture and ooze