A battery pack comprising: a secondary battery; and a battery management system connected to the secondary battery, wherein the battery management system includes: a voltage measuring part adapted to measure the charging voltage of the secondary battery; an open circuit voltage OCV measuring part adapted to measure the open circuit voltage of the secondary battery after an interruption of the charging of the secondary battery; a voltage comparing part adapted to compare the measured charging voltage and the measured OCV of the secondary battery with the first set voltage; a full-charge detecting part adapted to determine whether or not the secondary battery is fully charged in response to a signal from the voltage comparing part; a protection circuit adapted to control the charging of the secondary battery depending on a charged state of the secondary battery; and a charge/discharge controller electrically connected between the secondary battery and an external terminal (P+, P-) to control an electrical connection between the secondary battery and the external terminal (P+, P-) in response to signals from the full-charge detecting part and the protection circuit. a secondary battery; and a battery management system connected to the secondary battery, wherein the battery management system includes: a voltage measuring part adapted to measure the charging voltage of the secondary battery; an open circuit voltage OCV measuring part adapted to measure the open circuit voltage of the secondary battery after an interruption of the charging of the secondary battery; a voltage comparing part adapted to compare the measured charging voltage and the measured OCV of the secondary battery with the first set voltage; a full-charge detecting part adapted to determine whether or not the secondary battery is fully charged in response to a signal from the voltage comparing part; a protection circuit adapted to control the charging of the secondary battery depending on a charged state of the secondary battery; and a charge/discharge controller electrically connected between the secondary battery and an external terminal (P+, P-) to control an electrical connection between the secondary battery and the external terminal (P+, P-) in response to signals from the full-charge detecting part and the protection circuit. a voltage measuring part adapted to measure the charging voltage of the secondary battery; an open circuit voltage OCV measuring part adapted to measure the open circuit voltage of the secondary battery after an interruption of the charging of the secondary battery; a voltage comparing part adapted to compare the measured charging voltage and the measured OCV of the secondary battery with the first set voltage; a full-charge detecting part adapted to determine whether or not the secondary battery is fully charged in response to a signal from the voltage comparing part; a protection circuit adapted to control the charging of the secondary battery depending on a charged state of the secondary battery; and a charge/discharge controller electrically connected between the secondary battery and an external terminal (P+, P-) to control an electrical connection between the secondary battery and the external terminal (P+, P-) in response to signals from the full-charge detecting part and the protection circuit.