RV electrical trips people up because it is really two systems living together: 12-volt DC from batteries, and 120-volt AC from shore power, a generator or an inverter. Sort out which appliance runs on which and the rest gets much simpler.
The two systems
- 12V DC: lights, water pump, furnace fan, vent fans, the control side of the fridge and water heater. Runs off the house battery bank, always.
- 120V AC: air conditioner, microwave, most outlets. Runs off shore power or a generator — or off the batteries through an inverter, at a heavy cost in amp-hours.
Batteries: lithium vs lead-acid
Lead-acid (including AGM) is cheaper up front but you can only use about half its rated capacity and it is heavy. Lithium (LiFePO4) costs more, weighs roughly half as much, delivers nearly all its rated capacity, and charges much faster. If you will camp without hookups regularly, lithium usually wins over the life of the bank.
Solar, sized honestly
Solar does not power your A/C; it refills your batteries. Rough sizing: tally your daily amp-hour use (lights, fridge, fans, phone/laptop charging), then aim for panel wattage that can put that back with real-world sun — a common starting point for a couple is 200–400W of panels with a matching charge controller (MPPT preferred).
Surge protection is not optional
Campground pedestals fail in ways that cook RV electronics: open neutrals, miswired outlets, voltage sags and spikes. A portable or hardwired EMS-style surge protector checks the pedestal before passing power and disconnects on faults. It is the single best-value protection purchase in this hobby.
Habits that keep it boring
- Know your amperage: on 30A you cannot run A/C, microwave and a kettle at once.
- Check battery state of charge daily when off-grid; never leave lead-acid deeply discharged.
- Exercise the generator monthly under load if you carry one.
Before your next trip: run the free 47-item pre-trip checklist. Gearing up? The Camp-Ready Gear Guide ($17) covers 50 picks by budget tier, and the RV Life Launchpad course ($97) walks the whole system from rig choice to life on the road.