Power bank with a plurality of pluggable battery modules

A power bank has a station and a plurality of battery modules. Each of the battery modules can be positioned in a corresponding slot of the station in a pluggable way and is electrically connected to a charging-discharging control circuit of the station. When a main charging port of the station is electrically connected to a power supply, the charging-discharging control circuit receives electric power from the power supply via the main charging port and uses the received electric power to charge rechargeable batteries of the battery modules. When a main discharging port of the station is electrically connected to an electronic apparatus, the charging-discharging control circuit receives electric power from the rechargeable batteries of the battery modules so as to provide electric power to the electronic apparatus.