| 摘要 |
PURPOSE: To charge a plurality of lithium ion batteries in a short time without increasing the output current of a battery charger. CONSTITUTION: When the charging mode of either one of lithium ion batteries which are charged with constant currents first is switched to a constant-voltage charging mode, the charging current gradually decreases. The other lithium ion battery is simultaneously precharged with a charging current corresponding to the decreased amount of the decreasing charging current. The output current of a battery charger is prevented from increasing by controlling the sum of the charging current which charges the main lithium ion battery to the constant voltage and the charging current which precharges the other battery to nearly the same value. In addition, the residual capacity of the lithium ion battery to be charged first is detected before starting the charging so as to minimize the charging time of the battery. In addition, the other lithium ion battery is precharged while the main battery is charged to a constant voltage for a fixed period of time after the charging mode of the main battery is switched to the constant-voltage charging mode from the constant-current charging mode and, thereafter, the other lithium ion battery is charged with a constant current. |
