BATTERY SYSTEM

摘要

This battery system comprises: a secondary battery (7A) in which a laminated electrode connected to a positive electrode terminal and a negative electrode terminal is accommodated in a battery can (11A) and the positive electrode terminal and battery can (11A) are electrically connected; a secondary battery (7B) in which a laminated electrode connected to the positive electrode terminal and the negative electrode terminal is accommodated in a battery can (11B) and the positive electrode and the battery can (11B) are electrically connected; a cell can voltage sensor (9A) that measures a first voltage of the battery can (11A); a cell can voltage sensor (9B) that measures a second voltage of the battery can (11B); and a BMU (15) into which information corresponding to the first and second voltages measured by the cell can voltage sensors (9A, 9B) is input. The BMU (15) is characterized by making swelling detection information active based on the information above when the first voltage increases and the second voltage decreases at substantially the same time as the increase. Thus, the presence or absence of swelling in the battery can that accommodates the secondary batteries can be detected without inviting increased costs and with a simple constitution.