Abstract: Provided are battery packs and methods of fabricating these battery packs. A battery pack includes multiple battery cells stacked together along the center axis of the pack and electrically interconnected with each other by, for example, direct physical contact. The connections may be easily separable by pulling one cell away from another. The stack is enclosed by a pack housing that includes two ends caps and a middle section extending between and supporting the two end caps. One end cap may be removable for accessing to the stack. Furthermore, the end caps may be used to form electrical connections to the battery pack. The middle section of the pack housing may be used for thermal management of the pack. For example, the middle section may include a compartment for a heat transfer material for adding or removing the heat from the battery cells during their operation.