For reasons not relevant here, I tore down a battery pack containing three 18650 lithium cells. After a major struggle that involved drilling access holes into the side of the case and hammering the cells free of their silicone potting restraint, I was confronted with this:
Battery may explode or fire if mistreated. Yeah, that could happen.
Having pretty well ignored all the warnings, the damaged cells spent two days in the cold on the patio:
They seem unchanged, so I’ll dispose of them at the next electronics recycling event.
As it turns out, the gadget containing the pack subsequently died of a whoopise while trying to figure out how the pack’s boost regulator worked, so it joined the cells on the outgoing pile.
So it goes …