ON-VEHICLE BATTERY CONTROL DEVICE AND ON-VEHICLE BATTERY CONTROL METHOD

摘要

PROBLEM TO BE SOLVED: To provide a battery control device 1 capable of pre-heating an on-vehicle battery 2 by suppressing a decrease in service life due to excessive charging/discharging, and obtaining output characteristics of a stable on-vehicle battery 2.SOLUTION: A battery control device 1 comprises an on-vehicle battery 2 and a control unit 7. The on-vehicle battery 2 comprises a first cell group 21 in which two cells C1 are connected in series and a second cell group 22 in which two cells C2 are connected in series. The control unit 7 comprises: balancing means for setting the difference between a charging rate S1 of the first cell group 21 and a charging rate S2 of the second cell group 22 to a target differential amount St or higher when the vehicle state is not a use state; first connection switching means for switching the connection state of the first cell group 21 and the second cell group 22 to parallel connection when the vehicle state changes to the use state; and second connection switching means for switching the connection state of the first cell group 21 and the second cell group 22 to serial connection when the charging rate S1 of the first cell group 21 equals the charging rate S2 of the second cell group 22.SELECTED DRAWING: Figure 2