A power inverter is a device which converts battery output (DC, or direct current) into 230V AC mains electricity (alternating current). 230V AC is the type of electricity supplied by utility companies to run standard domestic appliances such as a TV, fridge, radio, lights or to charge a laptop / mobile phone etc. If you have a battery, connecting a power inverter will enable you to power household appliances in areas with no access to mains electricity.