re: WHY2025 badge batteries | goof lyrics@kitten from what I read (and made assumptions based on it) assuming it has a metal casing below the plastic coating is that either battery terminal really shouldn't get into contact with the metal shell because otherwise it might cause a short circuit, causing overheating and a thermal runaway which results in a fire or even explosion.
re: WHY2025 badge batteries | goof lyrics@kitten idk! It's a lot of assuming and a lot of figuring it's astonishingly hard to find concrete and easily understandable information why the plastic tingy is important.
Please do your own research and don't take my word on that since I have no clue and the effects of being wrong on that can be extremely dangerous. It could also be there for different reasons.