Patent ID: 8808907

Claim:
A battery module comprising: a cell unit including unit cells, the cell unit housed in a case, the case comprising: a first member having a top wall and a bottom wall each with a first guide portion, and an end wall, wherein the top wall and the bottom wall are flexible and each has a free distal end; a second member comprised of two side members each having a first rail portion configured to slide along the first guide portion to thereby engage the first member with the second member to form sides of the case; and a third member engaging an end of the cell unit, the third member having a top wall and a bottom wall each with a second rail portion configured to receive the first guide portion and an end wall positioned opposite the end wall of the first member, wherein each of the top wall and the bottom wall of the third member have an end surface facing opposite the end wall of the third member, each end surface having an engaging portion extending therefrom, and the free distal end of the top wall of the first member engages the engaging portion of the top wall of the third member and the free distal end of the bottom wall of the first member engages the engaging portion of the bottom wall of the third member, each free distal end biased against a respective engagement portion when the case is in a closed case position.