Over-discharge protection circuit for battery

The utility model discloses a battery overdischarge protection circuit, which is used for carrying out control protection on a battery in a discharge state and a load thereof, and comprises a power supply starting unit, a voltage detection unit and an output control unit. Wherein the power supply starting unit comprises a discharge fuse tube and a starting switch, and when the starting switch is pressed down, the battery starts to discharge; the voltage detection unit gives a driving signal and an indicating signal according to the battery voltage; and the output control unit realizes on-off control of the load through action of a relay. According to the technical scheme, battery electricity is directly used as power supply input of the whole unit, an external power supply circuit is not needed, and simplicity and convenience are high; meanwhile, parameters such as a voltage-regulator tube and a current-limiting resistor can be adjusted according to the battery voltage grade, parameters such as a relay and an