The BatteryProtect function disconnects the battery from the less important consumers before it is completely discharged (which would damage it) or before it no longer has enough energy to start the engine.

The BatteryProtect is a unidirectional device. It only allows current in one direction, i.e. either current to a consumer or with current from a charger, but not both currents at the same time. In addition, the current can only flow from the battery connection to the consumer connection. When used with a consumer, the battery must be connected to the battery connection; when used with a charger, the charger must be connected to the battery connection.