[DebNJim B]

The most I've seen mine draw is 3 amps and that's with the ice maker running. I turn that off when traveling. I have no trouble keeping the batteries up even on long days, I do however have a high output alternator. I have only one hybrid battery and it makes it all day and still is able to run the level up when we get to that nights stop. I keep a remote thermometer in it to monitor while driving. I generally leave the inverter on.
You should be OK with your set up although two batteries might be a good idea. My dealer told me two years after the sale that it should have had two, but of course he didn't give me two.