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 uni-directional device. It can only deal with the current in one direction, so either current to a load, or current from a charger, but not both currents at the same time. In addition to this, current only can only flow from the Battery terminal to the load terminal. In case of use with a load, the battery connects to the Battery terminal, and in case of use with a charger, the charger connects to the Battery terminal.

12/24 V
65 Amp
40 x 48 x 106 mm