BEP Battery Distribution Cluster f/Twin Outboard Engines w/Three Battery BanksBattery Distribution Cluster f Twin Outboard Engine w Three Battery Banks The 717 140A DVSR is designed for twin engine installations. It allows the port engine to charge both the port start battery and the house battery when the port VSR is engaged. It also allows the starboard engine to charge both the starboard start battery and the house battery when the starboard VSR is engaged. This gives you a combined charge from two engines into the house