I am using this RV temporarily and was curious how to use the Battery Access control panel near the entry door. There are 2 switches to "connect or disconnect". 1 for cabin and 1 for chassis. (There is also a switch to activate the stairs which I understand.) What defines the cabin and what defines the chassis? I will be using this RV with no ac hook up and running the genetator. Is there a series of steps once I pull into my spot and shut the engine off?