Much like a car, it is often 12 Volts with batteries that are designed to provide a high output but are not usually 'deep cycle'.
The first electrical system is to power the vehicle part of the RV. Most modern motorhomes actually have three discrete electrical systems powered by two separate sets of batteries. After getting the A/C power mostly squared away and tested, it was time to tackle the 12V DC 'house' power side of things.
