VEHICLE POWER MANAGEMENT SYSTEM AND POWER MANAGEMENT METHOD THEREOF

A vehicle power management system and a power management method thereof are provided. The power management method includes: determining, by a microcontroller, whether or not a voltage of an ignition-off signal is less than a voltage threshold when the microcontroller receives the ignition-off signal; stopping a vehicle power supply from charging a backup battery, and using the vehicle power supply to charge a back-end load; activating a counter of the microcontroller; stopping the vehicle power supply from charging the back-end load, and using the backup battery to charge the back-end load when a counting time of the counter reaches a first time threshold; sending, by the microcontroller, the ignition-off signal to the back-end load when the counting time of the counter reaches a second time threshold; and stopping the backup battery from charging the back-end load when the counting time of the counter reaches a third time threshold.