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 (1), whether or not a voltage of an ignition-off signal is less than a voltage threshold when the microcontroller (1) receives the ignition-off signal; stopping a vehicle power supply (P) from charging a backup battery (5), and using the vehicle power supply (P) to charge a back-end load (L); activating a counter (11) of the microcontroller (1); stopping the vehicle power supply (P) from charging the back-end load (L), and using the backup battery (5) to charge the back-end load (L) when a counting time of the counter (11) reaches a first time threshold; sending, by the microcontroller (1), the ignition-off signal to the back-end load (L) when the counting time of the counter (11) reaches a second time threshold; and stopping the backup battery (5) from charging the back-end load (L) when the counting time of the counter (11) reaches a third time threshold.