Parasitic draws will deplete the battery in my C after a few weeks. When I plug it into ground power at the house I use a black and decker battery maintainer plugged into the 120Volt wall plug and then into the 12 volt plug on the dash. Problem solved for me. It keeps just enough current to offset the draw.
As far as the year of the coach, mine is an 08 chassis and a 09 house. The manufacturer purchases large numbers of chassis and as they are finished and ready for sale then the manufacturer dates the unit. Mine was finished in 09 so it's an 09 Cambria. Federal law.