Vehicle battery cooling structure

1. A vehicle battery cooling structure comprising:

a vehicle body including a floor panel and a vehicle body frame member;

a battery unit attached to the vehicle body frame member and arranged below the floor panel, the battery unit including a battery and a battery case that houses the battery, the battery case including a most forward end having a laterally extending forward surface that faces toward a front of the vehicle and a most rearward end having a laterally extending rearward surface that faces toward a rear of the vehicle such that the laterally extending rearward surface is an exterior surface of a most rearward end of the battery unit, and the battery case being configured such that an air stream produced by forward motion of the vehicle strikes the most forward end of the battery case before passing transversely to the laterally extending rearward surface; and

a cooling jacket attached to the laterally extending rearward surface of the battery case;

the battery case including a rearward portion, a frontward portion and a middle portion, the rearward, frontward and middle portions having different heights, with the height of the rearward portion being highest, the height of the frontward portion being next highest and the height of the middle portion being lowest; and

the cooling jacket being disposed on the rearward portion of the battery case.

2. The vehicle battery cooling structure as recited in claim 1 , wherein

the floor panel and the upper surface of the battery case are vertically spaced apart to define an air flow passage therebetween that allows the air stream produced by the forward motion of the vehicle to pass therethrough, with the cooling jacket being exposed to the air flow passage.

3. The vehicle battery cooling structure as recited in claim 2 , wherein

the cooling jacket has an upper edge portion with a notch that forms a portion of the air flow passage.

4. The vehicle battery cooling structure as recited in claim 3 , wherein

the battery unit and the cooling jacket are provided as a single integrated unit that is detachably and reinstallably attached to vehicle body frame member.

5. The vehicle battery cooling structure as recited in claim 1 , wherein

the battery includes first, second and third battery groups, with the first battery group being arranged in a frontward position relative to the second and third battery groups, the second battery group being arranged between the first and third battery groups, and the third battery group being arranged in a rearward position relative to the first and second battery groups, and

the battery case includes a first cover portion covering the first battery group, a second cover portion covering the second battery group and a third cover portion covering the third battery group with the cooling jacket disposed thereon, the battery case having an upper surface in close proximity to upper ends of the first, second and third battery groups and with the first, second and third cover portions having different heights such that the third cover portion is higher than the first cover portion, which is higher than second cover portion.

6. The vehicle battery cooling structure as recited in claim 5 , wherein

the floor panel and the upper surface of the battery case are vertical spaced apart to define an air flow passage therebetween that allows the air stream produced by the forward motion of the vehicle to pass therethrough, with the cooling jacket being exposed to the air flow passage.

7. The vehicle battery cooling structure as recited in claim 6 , wherein

the cooling jacket has an upper edge portion with a notch that forms a portion of the air flow passage.

8. The vehicle battery cooling structure as recited in claim 7 , wherein

the battery unit and the cooling jacket are provided as a single integrated unit that is detachably and reinstallably attached to vehicle body frame member.

9. The vehicle battery cooling structure as recited in claim 1 , wherein

the floor panel and the upper surface of the battery case are vertical spaced apart to define an air flow passage therebetween that allows the air stream produced by the forward motion of the vehicle to pass therethrough, with the cooling jacket being exposed to the air flow passage.

10. The vehicle battery cooling structure as recited in claim 9 , wherein

the cooling jacket has an upper edge portion with a notch that forms a portion of the air flow passage.

11. The vehicle battery cooling structure as recited in claim 1 , wherein

the battery unit and the cooling jacket are provided as a single integrated unit that is detachably and reinstallably attached to vehicle body frame member.

12. The vehicle battery cooling structure as recited in claim 2 , wherein

the battery unit and the cooling jacket are provided as a single integrated unit that is detachably and reinstallably attached to vehicle body frame member.

13. A vehicle battery cooling structure comprising:

a vehicle body including a floor panel and a vehicle body frame member;

a battery unit attached to the vehicle body frame member and arranged below the floor panel, the battery unit including a battery and a battery case that houses the battery, the battery case including a most forward end having a laterally extending forward surface that faces toward a front of the vehicle and a most rearward end having a laterally extending rearward surface that faces toward a rear of the vehicle such that the laterally extending rearward surface is an exterior surface of a most rearward end of the battery unit, and the battery case being configured such that an air stream produced by forward motion of the vehicle strikes the most forward end of the battery case before passing transversely to the laterally extending rearward surface; and

a cooling jacket attached to the laterally extending rearward surface of the battery case;

the battery including first, second and third battery groups, with the first battery group being arranged in a frontward position relative to the second and third battery groups, the second battery group being arranged between the first and third battery groups, and the third battery group being arranged in a rearward position relative to the first and second battery groups, and

the battery case including a first cover portion covering the first battery group, a second cover portion covering the second battery group and a third cover portion covering the third battery group with the cooling jacket disposed thereon, the battery case having an upper surface in close proximity to upper ends of the first, second and third battery groups and with the first, second and third cover portions having different heights such that the third cover portion is higher than the first cover portion, which is higher than second cover portion.

14. The vehicle battery cooling structure as recited in claim 13 , wherein

the floor panel and the upper surface of the battery case are vertical spaced apart to define an air flow passage therebetween that allows the air stream produced by the forward motion of the vehicle to pass therethrough, with the cooling jacket being exposed to the air flow passage.

15. The vehicle battery cooling structure as recited in claim 14 , wherein

the cooling jacket has an upper edge portion with a notch that forms a portion of the air flow passage.

16. The vehicle battery cooling structure as recited in claim 13 , wherein

the battery unit and the cooling jacket are provided as a single integrated unit that is detachably and reinstallably attached to vehicle body frame member.

17. A vehicle battery cooling structure comprising:

a vehicle body including a floor panel and a vehicle body frame member;

a battery unit attached to the vehicle body frame member and arranged below the floor panel, the battery unit including a battery and a battery case that houses the battery, the battery case including a most forward end having a laterally extending forward surface that faces toward a front of the vehicle and a most rearward end having a laterally extending rearward surface that faces toward a rear of the vehicle such that the laterally extending rearward surface is an exterior surface of a most rearward end of the battery unit, and the battery case being configured such that an air stream produced by forward motion of the vehicle strikes the most forward end of the battery case before passing transversely to the laterally extending rearward surface; and

a cooling jacket attached to the laterally extending rearward surface of the battery case;

the battery unit and the cooling jacket being provided as a single integrated unit that is detachably and reinstallably attached to vehicle body frame member.

18. A vehicle battery cooling structure comprising:

a vehicle body including a floor panel and a vehicle body frame member;

a battery unit attached to the vehicle body frame member and arranged below the floor panel, the battery unit including a battery and a battery case that houses the battery, the battery case including a most forward end having a laterally extending forward surface that faces toward a front of the vehicle and a most rearward end having a laterally extending rearward surface that faces toward a rear of the vehicle such that the laterally extending rearward surface is an exterior surface of a most rearward end of the battery unit, and the battery case being configured such that an air stream produced by forward motion of the vehicle strikes the most forward end of the battery case before passing transversely to the laterally extending rearward surface; and

a cooling jacket attached to the laterally extending rearward surface of the battery case;

the cooling jacket being configured to form a liquid path that directs cooling liquid proximate to the laterally extending rearward surface of the battery case without exposing an interior of the battery case to the cooling liquid.