VEHICULAR ELECTRIC POWER SUPPLY DEVICE

摘要

PROBLEM TO BE SOLVED: To reduce the cost of a vehicular electric power supply device that comprises a first power storage body and a second power storage body.SOLUTION: A vehicular electric power supply device 10 mounted to a vehicle has: a motor generator 16 connected to an engine; a lithium-ion battery 27 connected to the motor generator 16; a lead battery 28 that is connected to the motor generator 16 in parallel with the lithium-ion battery 27 and is lower in terminal voltage than the lithium-ion battery 27; and a charge and discharge controller 51 that controls generation voltage of the motor generator 16 and controls charging and discharging of the lithium-ion battery 27. The charge and discharge controller 51 supplies electric power from the motor generator 16 to the lithium-ion battery 27 by increasing the generation voltage higher than the terminal voltage of the lithium-ion battery 27 and supplies electric power from the lithium-ion battery 27 to an instantaneous voltage drop protection load 33 by decreasing the generation voltage lower than the terminal voltage of the lithium-ion battery 27.SELECTED DRAWING: Figure 2