| 摘要 |
PROBLEM TO BE SOLVED: To provide a mobile communication terminal that has surpassed the deterioration of performance of a lithium ion battery serving as a built-in battery without increasing a manufacturing cost. SOLUTION: A mobile communication terminal includes a connection detection portion 1 for detecting an electrical connection with an attachable and detachable power source 20 that feeds DC voltages, a battery voltage and charge current detection portion 3 for detecting battery voltages and charge currents, a charge commencement directing portion 4 for directing charge commencement to a lithium ion battery 14, when the connection with the power source 20 is detected, and a charge control portion 5 for commencing charge according to the direction of charge commencement, for switching from constant current charge to constant voltage charge when a battery voltage reaches a switching voltage after the charge has been commenced, and for completing the charge according to charge currents during the constant voltage charge after switching. The charge commencement directing portion 4 is configured to makes comparison between a predetermined threshold lower than a switching voltage, higher than cut-off voltage during discharge and a battery voltage, and not to direct the commencement of charge if the battery voltage is higher than the threshold. COPYRIGHT: (C)2007,JPO&INPIT
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