Power inverter is a device that converts DC (also known as DC) into standard AC (alternating current). Inverters are used to operate electrical equipment generated by car or ship batteries or renewable energy sources such as solar panels or wind turbines. The direct current is stored in the battery, while the alternating current energy is what most electrical appliances need to run, so the inverter is necessary to convert the electric energy into usable form. For example, when a mobile phone is plugged into a car cigarette lighter for charging, it provides DC power; this must be converted to the required AC power through a power inverter to charge the mobile phone.