ON-VEHICLE POWER SUPPLY UNIT AND VEHICLE HAVING THE SAME

摘要

PROBLEM TO BE SOLVED: To improve fuel efficiency of a vehicle by charging and discharging a power storage section in a wider voltage range while suppressing degradation in a lead battery.SOLUTION: The on-vehicle power supply unit includes: a power supply section 1 including a lead battery 10 and a power storage section 20 electrically connected in parallel; a voltage detection section 72 for power storage section; an isolating switch 61 for lead battery that controls an output of the lead battery 10; an isolating switch 62 for power storage section that controls an output of the power storage section 20; a control circuit 65 that switches operation states of the isolating switch 61 for lead battery and the isolating switch 62 for power storage section; and a storage section 73 that stores a power storage section lower-limit voltage Vfor limiting discharge of the power storage section 20. Under such a state that a voltage of the power storage section 20 is higher than the power storage section lower-limit voltage V, the control circuit 65 turns OFF the isolating switch 61 for lead battery and turns ON the isolating switch 62 for power storage section to perform discharging into an electrical apparatus 50 on vehicle side from the power storage section 20.