3 deep cycle marine 100 amp hour batteries are charged by car’s alternator, solar power from panels mounted to the roof, and AC input from a standard 110v outlet (campground or house outlet.) A battery isolator prevents running down the car battery. A 200 amp circuit breaker installed for protection. Refrigerator, water pump, and power strip with usb and cigarette lighter charger are hard wired to batteries for constant output. 2200 watt pure sine wave inverter allows running microwave (700 watt, with surge up to 1100 watt) and is safe for charging laptop.