Disclosed is a power storage device. The power storage device according to the present invention comprises: a housing which is formed from a durable material and defines a space for the installation of a plurality of secondary batteries; a plurality of secondary batteries which are stored in the housing and are connected either in series or in parallel; a battery management system (BMS) which controls the charge and discharge of the plurality of secondary batteries and receives values for electrical properties; and a status setting switch which sets the status of the BMS. The present invention facilitates the configuration of a power storage system by virtue of the simple setting of the BMS.; Furthermore, if a fault has occurred in a given power storage device, a person responsible for the device can easily identify the faulty power storage device by sight, thereby facilitating easy maintenance and repair.