A battery pack (21A) according to embodiments of the present invention comprises a plurality of battery modules (11A-11D) connected to each other in either one or both of a series connection mode and a parallel connection mode. An identifying information setting section (25) sets identifying information on each of the plurality of battery elements (11A-11D). A connection mode managing section (47) manages the connection mode between the plurality of battery elements (11A-11D) by using the identifying information set by the identifying information setting section (25). The identifying information on each of the plurality of battery elements (11A-11D) is made up of a combination of first identifying information on the potential of the one of the plurality of battery elements (11A-11D) and second identifying information on the battery pack (21A) serving as a superordinate battery element to which the one of the plurality of battery elements (11A-11D) belongs.