COOLING SYSTEM FOR SECONDARY BATTERY

A secondary battery (10) is installed on an electric vehicle (90) and includes a cooling fan (40), a temperature sensor (61) and a controller (70). The controller (70) is configured to drive the cooling fan ( 40) at a fixed command value for a predetermined period, when the temperature of the secondary battery (10) becomes equal to or higher than a first predetermined temperature after the electric vehicle (90) is started. The controller (70) is configured to detect a presence or absence of an abnormality in the cooling fan (40) based on an actual rotational speed of the cooling fan ( 40) during the predetermined period. The controller (70) is configured to inhibit driving of the cooling fan ( 40) at the fixed command value when the temperature of the secondary battery (10) is equal to or higher than a second predetermined temperature that is higher than the first predetermined temperature. Figure 1