WHY2025 badge batteries@kitten TL;DR: It doesn't increase the risks.
Long: 18650 cells are more or less a minus pole all around except for the little tap at the end. That's +. Puncturing the outer plastic does nothing to the stability of the cell itself. The plastic is just a protective heat shrink. I have replaced it on a lot of cells that had signs of wear (a friend uses those for her vape). Big holes however expose more of the negative pole shell and with that increases the risk of shorts.
1
1
