And finally, if you want the option to run AC appliances off the batteries while off the grid and don't want to run the generator, then you will need an optional inverter as shown below.
Not shown on such a simple drawing is the inverter will either have it's own AC breaker or go through the main AC panel. It is highly dependent on if the inverter was installed as a factory option or installed by a owner or dealer as an aftermarket item.
These are just generic rough descriptions of the various setups. There may be specific differences in any individual coach so some or all of this may or may not apply to you.