bsinmich wrote:
There is the possibility that 7V reading was from a 6V battery. Newmar probably has 6V banks in series for 12V for the house. The house batteries may not be too bad. You should have a switch that says "store" and "use" (mine is 11 years older than yours) and you should use the "Store" position when not in use. My MH is stored in a barn with "store" selected and I fully expect it to start right up if the snow ever quits. 120" and counting on snow.
This is very possible: count the caps: three on a battery = 6 volt battery. 6 six caps (often two groups of 2) = 12 volt battery.