That was my idea to run the generator in the morning while underway and then use battery power overnight while anchored. I plan on running up and down the Tn river a few hundred miles for a few months.
Yeah, don’t run a genset at night while anchored—very antisocial behavior.
Good luck on your project. It’s good to keep in mind that all of devices you need to use have major efficiency losses, particularly the generator, charger, inverter and air conditioner. Each could easily be lower than 60% efficient, depending on the conditions of their use (warmup, percent of power capacity, etc. It would be wise to use a generator, charger, battery, and inverter that have double the expected power capacity in order to make up for efficiency losses. You should make sure that the batteries that you use can be charged in the amount of time that you plan.