VEHICLE POWER SUPPLY SYSTEM

A vehicle power supply system includes: a main battery; a sub-battery with output voltage; a power converter having an input end connected to the main battery and an output end connected to a motor and converting output power of the main battery to driving power for the motor; a voltage converter connected between the main battery and the sub-battery and stepping down the voltage of the main battery to the voltage of the sub-battery; a charging inlet connected to the main battery and connecting to a power supply device outside a vehicle; a capacitor connected between a positive electrode and a negative electrode of the input end; and a coil connected between the main battery and the voltage converter. The coil is connected to the capacitor not via a charging power path from the charging inlet to the main battery.