The present invention discloses a power bank circuit. The power bank circuit includes a charger circuit, a battery circuit, a power conversion circuit, a temperature detecting circuit and a current distribution circuit. The charger circuit receives an input voltage and provides a charging current to the battery circuit. The power conversion circuit converts a battery voltage to an output voltage and provides an output current. The temperature detecting circuit detects the temperature of the packaged structure. When the temperature of the packaged structure exceeds a first predetermined temperature, the current distribution circuit first reduces the output current. When the temperature of the packaged structure exceeds a second predetermined temperature, the current distribution circuit then reduces the charging current.