Abstract: A storage battery device includes: first and second battery systems including a plurality of first and second battery modules and a plurality of first and second monitoring units detecting module information that is information related to the battery modules, and respectively having first and second identification information; and a battery management unit configured to receive a lower-level communication frame containing the monitoring identification information and the module information from the monitoring units, and transmit, to an upper-level device of the battery management unit, an upper-level communication frame that contains individual identification information assigned to each of the monitoring units based on system identification information assigned to the battery systems, and the monitoring identification information, that also contains the module information detected by the first or the second monitoring unit corresponding to the individual identification information, and that has a larger data