The present invention provides a circuit for controlling the operation of a backup power supply, wherein the circuit comprises a switch unit, a control unit, and a processing unit; wherein the switch unit is configured to be operably coupled to an external power supply; wherein a first input terminal is configured to be operably coupled to a backup power supply, a second input terminal is configured to be operably coupled to the switch unit, the third and fourth output terminals of the control unit are configured to be operably coupled to an input terminal of the processing unit; the fifth and sixth input terminals of the control unit are configured to be operably coupled to a respective output terminal of the processing unit; and the control unit is configured to turn on and off the backup power supply.