Charge control system of battery pack

Provided is a charge control system of a battery pack. The charge control system includes a charge unit, a battery management unit, a charger management unit, and a voltage level shift unit. The charge unit charges a battery. The battery management unit includes first and second ports, determines one of a charge mode and charge stop mode of the battery according to whether the charge unit is disabled, and controls outputs of the first and second ports according to the determined result. The charger management unit is connected to a data input terminal of a charger, and controls an operation of the charger according to a voltage level of the data input terminal. The voltage level shift unit shifts a voltage level of the data input terminal according to the outputs of the first and second ports.