I was just thinking of a simple trap type. Some kind of pressure switch on a wire that when stepped on discharges electricity from your batteries. You could set the wattage to control your energy loss, with more watts doing more damage up to a lethal point. Could also serve as a stun for mechanoids. Would give a reason to have large battery stores for your defenses and would serve a similar roll as the bear trap currently does, with different uses and drawbacks.
This one is good. +1
Maybe add Tesla Coils as well :D