Having many 18650 battery cells to charge, I bought a few dirt cheap TP4056 modules (0.22 EUR per piece) and discovered that they are "not designed for" reversed polarity cells. In other words, reversed battery = instant magic smoke.
As I know for sure I will insert more batteries in the wrong orientation again sooner or later, I wondered what the best reverse polarity protection would be. This thread addresses this very topic, but at the time of this writing, it ends with:
Q: "Has anyone actually tested this solution in real life?"
A: "Good question..."
So I thought I would test and share the results here.