swollen 18650s?

[aznsx]

Anyone ever experienced / seen this? Anyone ever checked for it?

I read this and wondered, as I've never checked. No measurements, but apparently this user has an 18650 light with such a tight bore that it's essentially a 'go/no-go' gauge in this case, which establishes that swelling has occurred, which I guess is the primary point of interest here; how much is secondary, because I'd like to see 'zero' swelling myself. If some is to be expected, how much is 'OK'? I might question their charger, but apparently the issue is (cell type)-specific.

"In 2016, I purchased 8 protected KeepPower 3500mAh P1835J 18650 batteries. All fit in my Zebralight H600Fc Mk III at the time of purchase.
Over years of periodic (and sometimes frequent) use, all but one has swollen to the point that they no longer fit into this light — girth-wise. Another only just fits after I removed the label. One cell did this over the span of about three months and lodged itself firmly inside the Zebralight — meaning I had to epoxy a piece of wire to the bottom of the cell to extract it.
...
Strangely enough, four protected Sanyo NCR18650GA that I purchased around the same time have none of these issues."

 

[F89]

Lithium ion batteries are known to swell, particularly noticeably with things like lithium polymer battery packs.
I had to get rid of a 4S lipo recently that I use to power a small triple optic bike light. It swelled up like a balloon.
Never be complacent when charging and using any chemistry lithium ion.

 

[Rossymeister]

Never seen 18650's swell, but i usually don't keep any around for more than 3 years. Ive had 2 apple batteries swell over the years. An old macbook, and an iphone battery.

 

[aznsx]

I'm reminded that I posted this exactly one month ago, and no reports of "swollen 18650" (meaning cylindrical) cells to date. Possibly a red herring I guess(?). I guess it's also possible that few have 18650 lights with tight body bores, or check cell diameters periodically, so they just don't know about them when they occur. I will not however go so far as to conclude that what we don't know about can't hurt us;-)