Reverse polarity protection on model RC aircraft
Any reverse polarity protection you add will add to the complexity, weight, loss and unreliability of the system, so it's probably not worth it.

In short: you can't really add reverse polarity protection in this case without compromising normal operations, so it's better to be careful to never reverse the polarity in the first place.

Make sure you use polarized connectors like Deans Ultra plug in stead of crappy ones that can be reversed with a little man-handling.

Be careful to put the connectors on the batteries correctly.