To keep your battery topped up you can get something like this
Schumacher Ship n Shore
When you run your generator just have it plugged it and connected to the trailer battery, (which should be a deep cycle battery)
Or as other mentioned you can get some solar panels to toss on the roof, that could run those appliances all day and not make any noise... Which is sort of nice in the pits...
I hate being near someones pit set up who runs a generator 8 hours with a blown out muffler....