Sine wave inverters without external battery and support external battery bank. Pure sine wave inverter with battery charger. Ideal to provide stable power. The charger/inverter is simultaneously connected to a battery bank and 220 VAC mains. While 220VAC power is supplied, the batteries are charged. When no power is supplied 220VAC, DC/AC inverter SUPPLIESra energy from the battery and converts it to 220VAC. Ideal for powering emergency, and to design a system backup power supply equipment.