no 12 volt power from batteries.

by battery cut off switch - if your referring to the switch that goes between shore and battery, that is below the remote starter for the inverter, its working and in battery mode. but don't think it would interfere with 12v system as it just toggles between battery and shore for the plug ins. There is a finned box in the battery compartment, cleaned the terminals and ends in baking soda to remove any hidden corrosion. no switch on it that I can see but it does have a positive and negative post. no idea what that is but think it is the battery isolator. there are no cut off switches for the house batteries.