BATTERY HEATING SYSTEM, BATTERY PACK, AND ELECTRICAL APPARATUS

A battery heating system includes a switch assembly, and the switch assembly includes a first switch, a second switch, and a third switch. When the first switch is turned on and the second switch and the third switch are turned off, the first battery group and the second battery group are arranged in series connection and connected to a charging and discharging apparatus, for charging or discharging the first battery group and the second battery group after being connected in series. When the first switch is turned off and the second switch and the third switch are turned on, the first battery group and the second battery group are respectively connected to a battery heating apparatus to form a first loop and a second loop, and the first loop and the second loop are used for heating the first battery group and the second battery group.