When boondocking I connect a battery charger to my trailer batteries (2 x 12V in parallel) powered by a 400W inverter from a cig lighter in the truck for keeping the batteries topped off. We do not use an inverter to create 120V for anything in the trailer so we are very frugal with battery draw. A tea kettle is used to boil water for instant coffee, tea, & cocoa.
I now have a quiet 2KW generator the wife can use for her hair dryer rather than borrow power from a fellow camper in a motorhome so this winter will be different. I need 120v to inflate an airbed couch daily when guests bunk with us.
