Battery pack used as power source for portable device

Abstract

A battery pack includes a simple circuitry that improves the life cycle characteristic of the battery. The battery pack includes a plurality of cells connected in series. One of the cells is a lower rated capacity cell having a smaller capacity than the other cells. The lower rated capacity cell is disposed in a first tier of the plurality of cells from a negative terminal of the battery. Temperature and voltage of the lower rated capacity cell are detected to determine whether the lower rated capacity cell has reached the fully charged condition. When the fully charged condition is detected, charging of the battery is stopped. Similarly, based on the temperature and voltage detected, whether the lower rated capacity cell will soon be over-discharged is determined. If so, the use of the battery is stopped.

Dependencies are inferred from the claim text.