Lee-Ann: Somewhere in here you were pondering about running the air conditioner using the camper's batteries. I didn't notice if anyone answered you. Running the A/C with the camper batteries is just not going to happen. Sure, the possibility is there, but you'd only run it for a few minutes before they were drained.
As for running a microwave, the camper batteries will do that better, but still it's only for a small amount of usage, such as heating up something. Cooking a whole dish would probably be out of the question.