I have a 43qt Edgestar that uses a compressor. A stamp on the compressor says it uses 5 amps when running. To be sure its electrical needs are taken care of I wired it to a dedicated Group 34 battery then connected the battery to a 12v power outlet. I unplug the battery from the 12v power outlet when camped. It should run several days in that manner but I haven't camped long enough in one spot to find a limit. I also carry a 2000w Yamaha and a 30 amp battery charger just in case I want to stay a number of days in one spot.