Our 1500-Watt Power Inverter with Battery Charger and Transfer Switch has a built-in transfer switch that allows you to plug it into a regular AC outlet in your home. When the power goes out, your lights, electronic equipment and appliances will stay on. That's because this power inverter automatically switches to run off your battery bank. The charger built into this power inverter outputs 10 DC amps of charge. That will keep your batteries fully charged, so if and when the power does go out, your batteries will be ready to supply power to this backup power inverter. The charger built into this power inverter outputs 10 DC amps of charge. That will keep your batteries fully charged, so if and when the power does go out, your batteries will be ready to supply power to this backup power inverter.