BATTERY ASSEMBLY

A method for assembling a battery module, the method comprising: providing a cell tray defining a plurality of cell holes for holding cells; inserting cells into respective cell holes so that the cells each protrude from the cell tray at each end of the cell; attaching a first casing to a first side of the cell tray to enclose the cell ends protruding from the first side; and attaching a second casing to a second side of the cell tray to enclose the cell ends protruding from the second side.