The purpose of the present invention is to provide an assembled battery including a battery holder capable of holding single battery cells while automatically aligning the cells during assembly. In the assembled battery (100) according to the present invention, a plurality of single battery cells (101) arranged in a row and battery holders (144) disposed between the plurality of single battery cells (101) are held in a state of being mutually pressed in an arranged direction. The battery holders (144) include a positioning means (144f, 144g) that positions the single battery cells (101) by biasing the single battery cells (101), while being pressed in the arranged direction, in a direction intersecting the arranged direction.