General Description The FS325C protection IC for Li-ion/polymer rechargeable one-cell batteries maintains high accurate detections of the abnormal cell activities and the corresponding delay time in order to have protections against the events of over charge, over discharge, and over current. In the observation of an excess voltage across the battery for longer than a certain time, the FS325C activates a safety protection and turns off the external FET-M2 to inhibit the battery from over charging. When the battery voltage falls below a certain voltage for longer than a certain time, the FS325C detects the over discharge condition and turns off the external FET-M1 to cease over discharging. The over current protection is taken place when a large current is detected during discharge phase under normal condition, and the FS325C turns off FET-M1.