MountainTop, you aren't going to run the a/c off of batteries or solar! The air conditioner draws too much power. It is too hot to go out to the mpg and check on the fuse, but let's assume that the a/c is on a 15 A circuit. I'm going to really oversimplify here, not because I'm wanting to insult anyone's intelligence, but because this is actually a fairly common idea. That 15 amps at 120 volts is roughly equal to 150 amps at 12 volts. If you have a battery that is rated at 600 amp-hours, you have (in theory) four hours of a/c use before your battery dies. Actually, you can only pull a battery down about 50% before you damage it, so your 600 amp-hour battery will power your a/c for two hours before it needs recharging. If the a/c draws 20 A, you're looking at 90 minutes of air conditioning. In both cases I'm ignoring the draw of the inverter itself and the actual inefficiencies involved. In addition my examples assume that you use NO other electricity - no lights, radio, computer, etc.
Now, if you add a generator and/or solar panels AND are in a place where you use the a/c only for a brief period each day you may be able to get by. If you are serious about this, you're going to have some work to do. First replace all of the lights in your mpg with LED bulbs. Then find out how much current your camper draws when everything is off. (You might be surprised at how much is running even when you think everything is off.) Now go price some new deep cycle batteries, the solar panels and controller, and a generator. It might be cheaper to buy a new RV.