BATTERY SYSTEM AND METHOD OF CONTROLLING THE SAME

Provided is a battery system including a battery management module, a battery module, and a controller. The battery management module includes a main switch between an external terminal and a battery terminal, and a heating switch between the external terminal and a heating terminal. The battery module includes a cell, a heating element, and a control switch connected to the heating element. The controller is configured to detect a connection with a charger, detect a temperature of the cell, when the temperature is lower than a first value, turn off the main switch and turn on the heating switch and the control switch to supply heating power from the charger to the heating element, and when the temperature becomes higher than a second value by the heating element, turn off the heating switch and turn on the main switch to supply charging power from the charger to the cell.