In a battery pack including a plurality of prismatic rechargeable batteries arranged
in parallel with ventilation spaces being provided therebetween, the battery pack
is constituted so that cooling air is downwardly sent from above the battery pack
through the ventilation spaces. In accordance with a temperature detected with
a temperature detection sensor attached to the lower end of the rechargeable battery,
a blower fan is controlled by a control section. Moreover, a sensor placement concave,
which is separated from a space inside a battery case through a thin partition
wall, is provided on a bottom wall of the battery case of the rechargeable battery.
The temperature detection sensor is placed in the sensor placement concave so as
to be pressed against the partition wall.
