Battery container

1. A battery container which is to house a battery for a vehicle and which is to be attached between at least two frames disposed in the vehicle, the battery container comprising:

a bottom plate;

a wall member which is raised from a circumference of the bottom plate and which includes a side wall member disposed along the frames;

an outer frame which is attached to an outer side of the side wall member; and

an inner frame which is attached to an inner side of the side wall member, wherein

the outer frame and the inner frame are extended in a substantially same direction along the side wall member, and

the side wall member is clampingly held between the outer frame and the inner frame,

wherein the inner frame includes an upper plate member that extends in a horizontal direction from the side wall member, a vertical piece member that extends in a vertical direction from one end of the upper plate member to the bottom plate, such that a first hollow portion is defined by the upper plate member, the vertical piece member, the side wall member, and the bottom plate, wherein

wherein the outer frame and the side wall member define a second hollow portion,

wherein the outer frame includes a first lower plate member which is joined to the bottom plate, and a first attaching member which is joined to the side wall member, and

the inner frame includes a second lower plate member that extends from a lower end of the vertical piece member and joined to the bottom plate, and a second attaching member that extends from an opposite end of the upper plate member and joined to the side wall member, and

wherein the first attaching member of the outer frame and the second attaching member of the inner frame are integrally joined together across the side wall member,

the first lower plate member of the outer frame and the second lower plate member of the inner frame are integrally joined together across the side wall member, and

wherein a first closed cross-section structure defining a second hollow portion is formed by the outer frame and the side wall member, and

a second closed cross-section structure defining the first hollow portion is formed by the inner frame and the side wall member.

2. The battery container according to claim 1 , wherein

the first lower plate member is joined to the bottom plate at a first position, and the first attaching member is joined to the side wall member at a second position, and

the second lower plate member is joined to the bottom plate at a third position, and a second attaching member is joined to the side wall member at a fourth position.

3. The battery container according to claim 2 , wherein

at least one of a pair of the first position and the third position and a pair of the second position and the fourth position is shifted from each other.

4. The battery container according to claim 1 , wherein the upper plate member forms a seat surface to which the battery is to be fixed by a fastening member.

5. The battery container according to claim 1 , wherein a thickness of the outer frame is larger than a thickness of the wall member.

6. The battery container according to claim 1 , further comprising:

a bracket which is disposed outside the outer frame and to be attached to one of the at least two frames.