Enjoy your Greyhawk. The batteries, as Grumpy said, are both charged off of the engine and/or generator and being plugged in to a shore outlet. But the main thing to remember is that when you leave your motorhome for an extended period of time, say a couple of days, hit your battery cut off switch. This cuts off 99% of power draw on the batteries. In my 2013, this cut off switch is right by the steps so I can hit it just before closing the door. It also has a red light if on.
Me, Mrs., and Maggie