Discharge circuit

A discharge circuit for increasing discharge time of battery includes a discharging IC and a delay discharge circuit. When the discharging IC detects any voltage input, a minimum operating voltage of the discharging IC is set to 6.3V, when the discharging IC detects no voltage input, the minimum operating voltage of the discharging IC is set to 5.5 V. The delay discharge circuit is connected with a system voltage via a first current-limiting resistance, to make the discharging IC unable to detect any voltage input when only a battery is used as power source, thereby the minimum operating voltage of the discharging IC is set to 5.5V.