There will always be some form of parasitic draw on the house batteries when they are turned on. The draw may be very minimal, or somewhat more. Eventually, that draw and the natural discharge rate of the battery will deplete it. Depending on how much draw there is, that could take a week, or months. With minimum load (0.5A say) a good battery should last weeks between recharge drives, so turning off the battery wouldn't make any difference. If there is a larger parasitic load (inverters for example consume amp hours anytime they are on, even when they are not being used) turning off the switch may be worth while. Without a battery monitor though, you can only estimate and learn from experience what the loads are and how long you can go between recharges. At a minimum, you need a volt meter to start keeping track of your usage.
Agile Ride improvement package