POWER SUPPLY UNIT

摘要

PROBLEM TO BE SOLVED: To provide a power supply unit which extends the service life of secondary batteries.SOLUTION: A residual amount detector 71 of a monitor 7 detects a residual amount of secondary batteries 162 (162a to 162c). A control unit 73 transmits an indication value of output currents Ioa to Ioc to BAT converters 6a to 6c so as to increase the output currents Io2 (Ioa to Ioc) of a second power device 6 (BAT converters 6a to 6c) to which the secondary batteries 162 with a large residual amount is connected. The BAT converters 6a to 6c use an adjusting means to shift the output current-output voltage characteristics of the BAT converters 6a to 6c so that the current value of the output currents Ioa to Ioc when the output voltages of the BAT converters 6a to 6c are included in the output voltage of a first power supply device 5 indicates the indication value. The output currents Ioa to Ioc of the indication value are supplied to a DC apparatus 102 from the BAT converters 6a to 6c.