In one example embodiment, a battery unit includes a battery case, and a plurality of battery blocks stored in the battery case. The plurality of battery blocks are electrically connected together in series. In one example embodiment, a first plurality of the battery blocks form a first column and are arranged in a side-to-side configuration. In one example embodiment, a second plurality of the battery blocks form a second column and are arranged in an end-to-end configuration which is different from the side-to-side configuration.