| 摘要 |
PROBLEM TO BE SOLVED: To provide a charging controller which can set an optimum charging time according to the charging state or the type of a secondary battery by shortening the time required for charging. SOLUTION: An excess voltage detection circuit 12 requires a voltage drop generated by the internal resistance 16 of the secondary battery 15. A counter circuit 13 measures the time duration from which a terminal voltage VBAT changes for only voltage drop required by voltage detection circuit 12 during charging with a constant current. If the terminal voltage VBAT reaches the charging target value of the battery cell 17, the counter circuit 13 measures an elapsed time afterward, and when elapsed time accords with the measured result, constant-current charge by a fixed current control circuit 9 to a switching circuit 11 is ended. The charging time can be shortened by approaching the battery cell 17 accurately to the full charge state. COPYRIGHT: (C)2005,JPO&NCIPI
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