Going to add another: know the max # of amps your rig uses and don't use too many appliances at once as you may overload your electrical system and possibly set the rig on fire. Portable electric heaters can easily pull 15 amps. Know how many amps you're using at any given time. Inside a cupboard door we keep a list of our appliances and the amps they use so we can sum up which appliances should not be on at the same time.
Most appliances list watts and volts on their UL stickers. If they don't list the amps simply use this formula to determine the amps
Watts / volts = amps
Watts divided by volts equal amps
Safe camping!