The KISAE DC to DC Battery Charger is a 50 amp, fully automatic, multi-stage, multi-input battery charger with the ability to charge from either an alternator linked to a battery, or via solar power with the Maximum Power Point Tracking (MPPT) Solar Controller. With two inputs available, the house battery will be charged from either the running engine, or via the solar panels when stationary. The process to choose either engine or solar is fully automatic and both functions are controlled from within the unit itself without the need for external relays. KISAE DC to DC Battery Charger