The REDARC Battery Charger In-vehicle Battery Charger is the next generation in REDARC's DC to DC charging technology, with additional features that make it the most advanced dual battery charger on the market. Featuring a Maximum Power Point Tracking (MPPT) solar regulator, the Battery Charger will charge from both solar and the alternator simultaneously. With built-in 'Green Power Priority' it will select solar charging first, meaning less load on the alternator. Suitable for 12 or 24-Volt vehicle systems, the unit will also work with either standard or variable or smart alternators.