BATTERY CHARGING METHOD COMPRISES CHARGING CURRENT REDUCED IN DISCRETE STEPS WHEN BATTERY CHARGING CHARACTERISTIC REACHES PRE-DETERMINED VALUE

摘要

A high-speed charging system which accurately detects the fully charged state of a secondary cell and maintains it in that state. When the secondary cell is first charged with a predetermined current while charging characteristics are monitored. When a predetermined state of the secondary cell is detected, the charging is continued using a lower current. When the state representing the completion of charging of the secondary cell is detected, the charging operation is stopped. If a predetermined state of the secondary state is still detected instead of the completion of charging, however, the charging is continued with a still lower current, and these operations are repeated until the state representing the completion of charging is detected.