"Trickle" Charging used to be popular before modern multi-stage chargers came out
I would Depending on conditions, either plug in the RV full time or use a Battery Tender (TM) or battery Minder (TM) on them
Conditions:
1: Does RV have a good 3-stage converter such as a Progressive Dynamics Wizard controlled unit or a low end single stage such as the parallex 7300 or worse yet the magnetek 6300 IF 3-stage Then:
2: Is there a handy source of 120vac,, If yes, Plug in,
Else
Mark all leads with red/black tape or paint so you know how to re-connect, if multiple leads on same connector bind them together (Bolt or zip tie) remove batteries to place of power Set them on scrap wood (more on that later) and hook up the battery tender/minder device.
Why set 'em on scrap wood?
Myth: Concrete floor will damage battery
Fact: Battery acid on outside of battery case can damage floor
Fact: Scrap wood very cheap to replace if above fact happens, Floor not so much.
IF battery is a FLooded wet cell type, check fluid level and add distilled water as needed before storing, fully charge
Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times