A battery pack is disclosed. The battery pack includes a cell with a spacer, and a cap mounted on the spacer. The spacer and cap are mated to form a cavity to accommodate the components (i.e. busbars, circuit board, an insulator) of the battery pack. The spacer and cap have a series of mating surfaces for the components, wherein the mating surfaces have different heights to be recessed relative to each other to create spaces for accommodating the components. The recesses, channels, steps and raised portions correspond in geometry to the components so that they can be assembled while removing the tolerance accumulation associated with multiple standoffs.