Battery warming-up system

A battery warming-up system comprising:

• a compressor that compresses and discharges a refrigerant;
• an air-conditioning heat exchanger that heats an air-conditioning air flow to be sent to an air-conditioning space by using, as a heat source, a refrigerant discharged from the compressor or a fluid heat-exchanged with the refrigerant discharged from the compressor;
• a battery heat exchanger that heats a battery air flow to be sent to a battery by using, as a heat source, a refrigerant discharged from the compressor or a fluid heat-exchanged with the refrigerant discharged from the compressor;
• an air-conditioning blower that generates the air-conditioning air flow passing through the air-conditioning heat exchanger;
• a battery blower that generates the battery air flow passing through the battery heat exchanger;
• and
• a controller that controls the air-conditioning blower and the battery blower, wherein
• the controller executes a battery warming-up mode of controlling at least one of the air-conditioning blower and the battery blower such that an air-side temperature efficiency in the air-conditioning heat exchanger is higher than an air-side temperature efficiency in the battery heat exchanger.