BATTERY TEMPERATURE CONTROL DEVICE

A battery temperature control device includes a heating medium circuit that connects a battery heat exchanger, an outside air heat exchanger, a heating medium pump, and a flow rate regulating unit. The outside air heat exchanger is connected in parallel to the battery heat exchanger. The flow rate regulating unit adjusts a flow rate of the heating medium in a first path through which the heating medium flows via at least the outside air heat exchanger and a flow rate of the heating medium in a second path through which the heating medium flows by detouring around the outside air heat exchanger. The control unit controls the flow rate regulating unit to adjust a ratio between a flow rate of the heating medium in the first path and a flow rate of the heating medium in the second path.