METHOD FOR DETERMINING ABNORMALITY IN BATTERY PACK, AND DEVICE FOR DETERMINING ABNORMALITY IN BATTERY PACK

A method for determining an abnormality in an assembled battery that is formed by connecting, in series, a plurality of parallel bodies each formed by connecting a plurality of secondary battery cells (2) in parallel, includes detecting swelling in each of the secondary battery cells (2) by using a detection sensor (5) mounted on each of the secondary battery cells (2), and determining, based on swelling detected in two or more of the secondary battery cells (2), that an abnormality has occurred in a specific secondary battery cell among the two or more of the secondary battery cells.