Steel ammo cans can be your friends. I leave the lids closed, but not latched. I'd try the dropped batteries, just watch them carefully when charging, and check for heat, and/or puffyness. Either one of those while charging, and I'd scrap them. I've dropped some before, but on a carpet floor, no problem. Also, I've found a pretty big difference in the quality of different brands of lipo's. Some good, some pretty cwappy. Most of the time, you get what you pay for.