RV air conditioner units use AC power (Shore power for the post at that campground). To supply AC power in the amounts needed to run it while moving down the road or while not hooked up to a power pole, you will need a generator. For one typical RV unit (13,500 BTU) you need a minimum of 2.5K generator. I would suggest you get no less than a 3K generator. Better to have more than less. To run an AC unit off of batteries is doable (I did work it out) it just takes a pile of batteries. David objected so we will use a cheap Harbor freight genny (6500 watt for $600) that we will take apart to mount up under the bus.