Power source unit

1. A power source unit, comprising:

a battery module including a stack and a coupling member that binds the stack, the stack including a plurality of battery cells aligned; and

a container comprising a container body that accommodates therein the battery module and a cover that closes an upper opening of the container body, the container body comprising a bottom wall and first, second, third, and fourth side walls,

wherein the coupling member faces an inner surface of the first side wall,

wherein the container includes a rib projecting from inner surfaces of the second, third, and fourth side walls toward a surface of the battery module,

wherein a top end portion of the rib is located separately from the coupling member, and

wherein a region of the inner surface of the first side wall, which is opposed to the coupling member, is devoid of the rib.

2. The power source unit according to claim 1 , wherein said inner surface of the first side wall is different, with respect to placements of the rib, from the inner surfaces of the second, third, and fourth side walls opposing the coupling member.

3. The power source unit according to claim 1 , wherein at least one of the battery cells includes a safety valve located on a face of the battery cell opposing the coupling member, and

wherein the coupling member includes a hollow space.

4. The power source unit according to claim 3 , wherein the battery cell further includes an electrode terminal on the face of the battery cell opposing the coupling member, and

wherein the face opposing the coupling member is oriented to oppose a side wall of the container.

5. The power source unit according to claim 1 , wherein at least one of the battery cells includes an electrode terminal on a face of the battery cell opposing the coupling member, and

wherein the face opposing the coupling member is oriented to oppose a side wall of the container.

6. The power source unit according to claim 1 , wherein the stack is held between holding plates respectively provided on side faces of the stack, the holding plates being fixed to the coupling member,

wherein respective peripheral edges of the holding plates are connected via a beam member, and

wherein the holding plates and the beam member are formed as portions of a single sheet of a bent metal plate.

7. The power source unit according to claim 6 , wherein the rib is provided on said inner surfaces of the second, third, and fourth side walls opposing at least one of the holding plates.

8. The power source unit according to claim 6 , further comprising:

an electric device attached to at least one of the holding plates,

wherein the electric device includes a wall taller than a height of parts included in the electric device and projecting from a side of the holding plate, and

wherein a top end portion of the wall is oriented to oppose a top end portion of the rib.

9. The power source unit according to claim 1 , wherein the container comprises a synthetic resin.

10. The power source unit according to claim 1 , wherein at least one of the battery cells includes an electrode terminal projecting in a horizontal direction on a face of the one of the battery cells opposing the coupling member.

11. The power source unit according to claim 1 , further comprising:

holding plates provided on side faces of the stack,

wherein peripheral edges of the holding plates are connected via a beam member, and

wherein the holding plates and the beam member are formed as portions of a single sheet of a bent metal plate.

12. The power source unit according to claim 1 , further comprising:

holding plates provided on side faces of the stack,

wherein the rib is provided on said inner surfaces of the second, third, and fourth side walls opposing at least one of the holding plates.

13. The power source unit according to claim 1 , further comprising:

holding plates provided on side faces of the stack; and

an electric device attached to at least one of the holding plates,

wherein the electric device includes a wall projecting from a side of the at least one of the holding plates, and

wherein a top end portion of the wall is oriented to oppose a top end portion of the rib.

14. The power source unit according to claim 1 , wherein said inner surface of the first side wall has a different structure, with respect to placements of the rib, than the inner surfaces of the second, third, and fourth side walls.

15. The power source unit according to claim 1 , wherein the inner surface of the side walls is flat.

16. The power source unit according to claim 1 , wherein the inner surface of the first side wall is devoid of the rib.

17. The power source unit according to claim 1 , wherein an entirety of the inner surface of the first side wall is devoid of the rib.

18. The power source unit according to claim 1 , wherein the first side wall includes a reinforcing rib projecting from an outer surface of the first side wall, the reinforcing rib extending along an upper edge of the first side wall.

19. The power source unit according to claim 1 , wherein said inner surface of the first side wall is different, with respect to placements of the rib, from each of the inner surfaces of the second, third, and fourth side walls.

20. The power source unit according to claim 1 , wherein the region of the inner surface of the first side wall, which is opposed to the coupling member, faces a region of the inner surface of the third side wall that includes the rib.