Load Protection Module

In battery-powered circuits, the protection serves both to stop the operation of circuits that would not work correctly at too low a voltage, and to prevent excessive battery discharge, to avoid damaging it or to keep the little remaining energy available for other, higher-priority circuits.
The choice to power the load circuit with a relay that is active when the voltage is OK, and to disconnect it otherwise, stems from one consideration: if the load is battery-powered, it is clear that the relay must be de-energized while the battery is discharging, otherwise it would discharge it further and, at some point, the relay would drop out again, reconnecting the load — which would in turn cause a further discharge.

The circuit does not allow monitoring of the same supply voltage it is powered from.