If you don’t camp in full service campgrounds (I hope you don’t) then you are forced to power your camper with a 12 volt battery bank. You may have charging solutions such as solar (preferred) or maybe a generator (I hope not — too noisy).
Camping off the electrical grid requires monitoring your power consumption and in most cases conserving energy to some degree. Most campers come with automotive-type incandescent bulbs, which aren’t very efficient and are power hogs.