Vehicle power supply system
In a vehicle power supply system, when a main power supply device is normal, a backup controller turns on a switch circuit and turns off a switch circuit to supply power from the main power supply device to a load unit LD 1 and a load unit, and can travel a vehicle in a normal mode which is in a normal driving state. On the other hand, when the main power supply device is abnormal, the backup controller supplies power from the backup battery to the load unit and does not supply power from the backup battery to the load unit by turning on the switch circuit and turning off the switch circuit, and can travel the vehicle in the limit mode in which the functions are more limited than in the normal mode.
1. A vehicle power supply system, comprising:
a main power supply device that is mounted on a vehicle and supplies power to a first load unit and a second load unit; and
a backup power supply device that is mounted on the vehicle and supplies power to the second load unit when the main power supply device is abnormal, wherein
the backup power supply device includes a first switch circuit that switches a connection with the main power supply device, a backup battery that stores power supplied from the main power supply device and supplies power to the second load unit, a second switch circuit that switches a connection between the backup battery and the second load unit, and a controller that controls the first switch circuit and the second switch circuit,
when the main power supply device is normal, the controller turns on the first switch circuit and turns off the second switch circuit to supply power from the main power supply device to the first load unit and the second load unit such that the vehicle operates in a normal mode, and
when the main power supply device is abnormal, the controller turns on the second switch circuit and turns off the first switch circuit to supply power from the backup battery to the second load unit and not to supply power from the backup battery to the first load unit such that the vehicle operates in a limit mode which is different from the normal mode, wherein
the backup power supply device includes a discharge circuit that discharges the power of the backup battery, and a third switch circuit that switches a connection between the backup battery and the discharge circuit, and
the controller turns on the third switch circuit and turns off the second switch circuit to cause the discharge circuit to discharge the power of the backup battery and estimate a deterioration state of the backup battery.
2. The vehicle power supply system according to claim 1 , wherein
the first load unit and the second load unit include respective devices that are operated together when the vehicle operates in the normal mode, and
the device of the first load unit does not operate and the device of the second load unit operates when the vehicle operates in the limit mode.