I had our dealer install a battery disconnect switch, but it doesn't completely disconnect them. Darn things still drain some. Not sure what the problem is, and my dealer is 2 hours away.
In the Fall, I tailgate for football games and store my RV off site. It would be ideal if I could disconnect the batteries completely to preserve them. Sometimes we got 3-4 weeks between games, so they just sit.
For now though, I just need some moderately priced 12v deep cycle batteries. We don't use a lot of power, as a generator is used during the game weekends, and during the Spring/Summer camping season, we typically have hookups. A couple of deep cycle 24/27 batteries is more than enough.