I’ll put this in plain English. All the above posts give you information, based on numbers you don’t seem to know.
A 3000 watt inverter with 2 batteries is designed to run a few items for a short period of time when you are not hooked to shore power and don’t want to start the generator
The setup you have is more for convenience than anything else. You can make a cup of coffee or warm something in the microwave. Maybe watch tv for a few hours in the evening.
You say you don’t like the noise? Expensive? A window A/C is not quiet and to upgrade to a battery/inverter solution to do what you want to do is really expensive. At /1/2 gallon of fuel an hour you can run that generator for a lot of hours before breaking even on what you need to do what you want to do.
If you feel your generator is too loud. Have someone look at it make sure the muffler is still good, the gasket to the exhaust are ok, and the exhaust pipe is pointing the right way. In my previous coach I replaced the muffler, manifold gaskets (they are prone to failure) and made sure my exhaust pipe was directed outward. I could not even hear the generator with the A/C on. It made more noise.
2006 Winnebago Journey