The 4000 watt 12 volt low frequency AIMS Power inverter charger transforms DC (direct current) power, stored by batteries, into AC (alternating current) electricity that can be used to run your various tools and appliances. This inverter also has a built in AC-to-DC battery converter charger, which allows users to recharge their battery bank from an AC source such as a fuel-powered generator, shore power or a regular outlet at home. The built in battery charger features a seven type battery selector and 3 stage charging, for safely and effectively charging your battery source. Use this product for renewable solar, off-grid, mobile and emergency backup power applications anywhere that uses 110 or 120 volts of alternating current. This inverter is ideal for use in an RV as well, allowing you to shut off your noisy generator while dry camping but still be able to enjoy all of the amenities of home.