Vehicle battery cooling device

1. A vehicle battery cooling device, comprising:

a battery case for housing a plurality of batteries to be mounted on a vehicle;

a fan for circulating air for cooling the batteries by drawing air through the battery case;

an air inlet disposed on each of a pair of side wall portions of the battery case facing each other for introducing air from outside the battery case;

an air outlet disposed on a bottom wall portion of the battery case for exhausting air from the battery case by being drawn by the fan;

two first frames extending in a front-rear direction of the vehicle and forming a part of a vehicle frame of the vehicle;

at least two second frames extending in a vehicle-width direction of the vehicle and forming a part of the vehicle frame of the vehicle, while being connected to the two first frames; and

a lower plate for sealing a lower side of a space surrounded by the two first frames and the at least two second frames,

wherein the battery case is disposed above the space, and air inside the battery case is drawn by the fan first through the air outlet and then through the space when the fan is operated.

2. The vehicle battery cooling device according to claim 1 , further comprising:

an air introduction duct for introducing air from outside through one air introduction port and guiding the air to each of the air inlets by branching the air,

wherein the one air introduction port is disposed distant from an external heat source.

3. The vehicle battery cooling device according to claim 1 , further comprising:

a communication hole disposed in the lower plate for communicating between the space and outside,

wherein the communication hole is disposed at a position opposite to the fan across the air outlet in the vehicle-width direction.