A battery pack includes a plurality of battery units that are side by side along a first direction, a connection member that connects the battery units in series, in parallel, or in series and parallel, the connection member being adjacent to one surface of each battery unit of the plurality of battery units, an upper cap on and accommodating the connection member, upper portions of all of the battery units being inserted into the upper cap, a lower cap that is spaced apart from the upper cap by a predetermined gap, lower portions of all of the battery units being inserted into the lower cap, and a label that at least partially surrounds the battery units exposed between the upper cap and the lower cap. The upper cap and the lower cap fix an arrangement of the battery units.