A battery pack raises an alarm under overheated or high pressure
conditions in the battery pack. The alarm is raised from the battery pack
or an external device that is coupled with the battery pack when the
temperature or the pressure of the battery pack exceeds a predetermined
level. The battery pack includes a terminal that is coupled with a
charging device or an external device, a battery cell coupled with the
terminal so that the battery cell can be charged or discharged, a sensor
that is installed in the battery cell to detect at least one of a
temperature and a pressure of the battery cell, and an alarm unit that
compares a value detected by the sensor with a reference level and raises
an alarm for a user when the value detected by the sensor exceeds the
reference level.