I put a piece of large diameter fuel tubing over the male connector on the packs when not in use. I also stick a piece of plastic spiral wrap over the female connector for added protection. I cover the female connector with heat shrink tubing all the way and I also cover the base of the male connector with heat shrink. There is no exposed connector showing when the batts are connected.

And I always wire my packs the same way: Male connector on -, female connector on +. No way to get reverse polarity.