BEP Twin Battery Management System - Square.

We use this one all the time in our Cruisecraft and Yellowfin boats. The Battery Management System makes twin battery charging easy! Pre-assembled module with solid links and application labels combining three 701 Mini Battery Master Switches with a 100 amp Voltage Sensitive Relay. It's easily connected to the existing wires, providing a fully automatic battery management system and provides for isolation of start and house batteries independently with the ability to emergency parallel supply from both. The VSR  (Voltage Sensitive Relay) automatically prioritises charging of the start battery. When the engine is first started the relay is open and remains open until the start battery has reached a preset 13.7 volt. At the rated Voltage, the relay closes providing charge to both batteries (start and house). When the Voltage drops below 12.8 volt (when the engine is stopped), the VSR disengages, separating the batteries. It eliminates possibility of draining the start battery and protects electronics powered by the house battery from harmful engine starting spikes. Dimensions are 140mm X 140mm wide X 75mm.