Mary,
In addition to parasitic loads (clock, CO2 detector, etc.), batteries will self discharge over time and can be damaged...especially if cold. So you should either keep the RV hooked up to power (if you have a three or four stage charger)or go out and plug it in for a day or two once a month if you have the typical (cheap) RV converter (just don't forget to unplug it after a day or two). If you can't provide any power to the unit while in storage, you may want to remove the house batteries and store them in a garage with them connected to a good trickle charger. You might also want to remove the batteries from the smoke detector, etc.
Hope this helps,
Steve
