I guess I just never thought about it, but a quick-and-dirty web search shows that most (all?) of those things are 12VDC powered, no doubt because most shooters have to haul them out to a field someplace to use them. I could not find any specs on input current requirements, but that said, I still would guess that it would be relatively easy to find a power supply that would run one of these things. The power supply, of course, would get plugged into an outlet. Doing it that way would still give you the full selection of available units. Anyway, good luck!
Tim