Victron Battery Protect

The BatteryProtect disconnects the battery from non-essential loads before it is completely discharged (which would damage the battery) or before it has insufficient power left to crank the engine.

The BatteryProtect is a unidirectional device. It can only handle current in one direction, either current to a load or current from a charger, but not both currents at the same time. Additionally, current can only flow from the Battery terminal to the Load terminal. In the case of use with a load, the battery connects to the Battery terminal, and in the case of use with a charger, the charger connects to the Battery terminal.