This paper presents a single stage smart battery charger for marine applications. High energy efficiency is a unique advantage of the proposed charger. It has dual outputs; it can charge two batteries separately at the same time. The demonstrated topology has a fault tolerant (FT) capability in case of dual open switch faults. In addition it can be used in parallel mode to reduce the charge time significantly or in standalone mode to improve light load efficiency. A control technique and fault detection (FD) method is also developed for the proposed charger. To validate the theory, a 600 W, 24 VDC dual output battery charger with universal input 120/230 VAC is simulated in Matlab/Simulink under different load and input voltage conditions.