An inverter, a battery charger, and an automatic transfer relay, all in one! Inverter Chargers are extremely handy devices that convert DC power from the batteries into household AC power, as well as convert AC power into DC power that can charge deep cycle batteries. Renogy inverter chargers feature an internal transfer switch that automatically detects when you’re hooked up to another power source, like shore power or generator power. The transfer switch then transfers any power load to the new AC power source (shore power/generator) and uses that source to start charging the battery.