| 摘要 |
PROBLEM TO BE SOLVED: To provide a battery unit which includes an internal storage battery and suitably performs fail-safe processing when defective connection between the battery unit and an external storage battery occurs.SOLUTION: A battery unit U is provided which includes a lithium ion storage battery 30 and of which a first terminal P1 is connected to a lead storage battery 20 and a second terminal P2 is connected to a rotary machine 10. The battery unit U further includes: paths L1, L2 for connecting the lithium ion storage battery 30 to a battery node N1 between the terminals P1, P2; a switch 51 on the path L1, a first bypass path B1 connecting an auxiliary terminal P4 to which the lead storage battery 20 is connected to the battery node N1; a switch 55 on the first bypass path B1; and a control unit 60. The control unit 60, when a detection value of voltage of the first terminal P1 is lower than a predetermined value under a condition where the switch 51 is in an OFF state, determines the occurrence of defective connection in which the lead storage battery 20 is not connected to the first terminal P1 and controls both of the switches 51, 55 to ON states. |
