BATTERY PACK

A battery pack is provided. The battery pack includes a housing, a plurality of battery sets arranged in the housing, and a power supply system. The power supply system includes a switch control circuit for controlling a series-parallel connection mode of the plurality of battery sets, a main control chip for controlling the discharge of the plurality of battery sets by the switch control circuit, a wake-up circuit for waking up the power supply system of the battery pack when the main control chip receives a wake-up signal, a self-locking circuit connected to the switch control circuit which switches to a disabled state when the self-locking circuit is triggered; and a USB circuit and an extended power output interface, connected to the plurality of battery sets for outputting power to charge external devices.