While our lithium ion battery from Lithionics already has a battery monitor, it’s important for our charger (Victron Multiplus) understands the State of Charge (SOC) of our battery. Unfortunately, the Lithionics Battery Management System (BMS) doesn’t interact directly with our Multiplus so we have to add a battery monitor seen here. This will report back to the charging circuit to let it know when and how much power to put back into the battery.