A battery pack including a stack, the stack including a plurality of cells having different polarities at top and bottom surfaces thereof, the plurality of cells being arranged such that at least two cells are arranged along a short axis of the stack when viewed from top or bottom surfaces of the cells, and center connecting lines of adjacent cells along a long axis of the stack are other than perpendicular to the short axis; and conductive plates electrically connecting the plurality of cells to each other, each of the conductive plates including connection parts electrically connected to the cells and a linking part between the connection parts, wherein each of the connection parts includes at least two welding points and a line connecting the welding points, the line being parallel with the short axis of the stack.