A battery assembly having batteries connected in series to form rows and columns of battery cells into packs that combine the energy of multiple batteries. The battery cells are joined together to form columns of cells connected mechanically together by an exterior connection sleeve, and mechanically and electrically connected together by a conductive epoxy joining the end of one cell to the end of an adjacent cell in series. The columns of cells are mounted and held in place by racks, with bolts passing through the racks to form a sandwich structure that secures the position and orientation of the cells and columns, and that maintains the electrical connection between joined cells. Perpendicularly disposed to the direction of the columns are a series of conductive bands that join adjacent cells together along rows of cells.