Power storage system

A power storage system comprising:

• a plurality of power storage modules each of which includes at least one cell and that are connected in series;
• and
• a management device that manages the plurality of power storage modules, wherein
• each of the plurality of power storage modules includes a first insulation unit containing a primary side and a secondary side that are insulated from each other, a first communication unit outputting a signal containing information of the at least one cell to a communication line, the first insulation unit insulating the first communication unit from the at least one cell, and
• the management device includes a second communication unit communicating with the first communication unit, a second insulation unit containing a primary side and a secondary side that are insulated from each other, and a circuit unit insulated from the communication line by the second insulation unit, and
• wherein reference voltages of each of the first communication unit and the second communication unit are generated by a voltage generated by the plurality of power storage modules and the reference voltages are set to a voltage predetermined between a voltage at one end and a voltage at the other end of the plurality of power storage modules.