Electric power storage system

摘要

Since a continuous short circuit that occurs between both terminals of an assembled battery may cause breakdown, destruction, or explosion due to heat, current supply to the assembled battery needs to be stopped at an early stage. Even when the short circuit occurs instantaneously, storage batteries of the assembled battery may be thermally and potentially damaged, and the assembled battery may be continued to be used while the damage is not noticed and the reliability is impaired. Disclosed is an assembled battery which comprises a plurality of storage batteries connected in series. The capacity of at least one of the storage batteries during high-rate discharge is lower than those of the other storage batteries. The polarity of a specific storage battery is inversed during external short circuit so that damage to the other storage batteries is avoided.