If I’m reading this right you will have it basically in storage. I have my original house battery disconnected from the coach. All I use it for is the tongue jack. I use a $15 solar charger from Academy and it keeps it nicely topped off. If you’re just looking for a maintainer to supply the phantom loads on your trailer, a little plastic 50 watt or so plastic panel will probably work. The beauty of these is they’re cheap, no mounting required, no fancy controllers and will keep your battery charged.
Im holding on for the you’re an idiot posts!