Well, if you are worrried that you may short the battery positive to the body negative, the shape of the copper should prevent that in all standard battery formats, plus I am considering coating the exposed copper on battery side by insulation. Either liquid electrical tape or some epoxy, not sure which or if jet. I’ll do some measurements, tests and decide based on that. I may not do the coating if I deem it safe for my use. I am talking about the copper insert man of light is designing: MF01 Mini / MT07- Mod/Upgrade - Copper Heatsink Cover Plate