ENERGY STORAGE DEVICE

An energy storage device includes: a plurality of bipolar batteries arranged in an arrangement direction; a housing case that houses the bipolar batteries; and a cooler disposed between adjacent ones of the bipolar batteries in the arrangement direction and including a flow path provided therein. When viewed in the arrangement direction, the cooler includes a first protruding portion that protrudes into the housing case from between the bipolar batteries, and a second protruding portion that protrudes out of the housing case. A weak portion configured to rupture at a pressure lower than a pressure resistance limit of the housing case is provided on each of the first protruding portion and the second protruding portion.