Storage battery system

A storage battery system comprising:

• a storage battery comprising a plurality of battery modules, each of the plurality of battery modules being configured by connecting battery cells in series;
• a plurality of voltage monitoring circuits for individually monitoring a voltage of the battery cells that constitute the battery module, each of the plurality of voltage monitoring circuits being provided in accordance with each of the battery modules;
• and
• a control device that is connected to the voltage monitoring circuits in a circular shape, and controls charging and discharging of the storage battery on the basis of monitoring information that is obtained by carrying out communication with the voltage monitoring circuits,
• wherein the control device comprises a determination unit that calculates an estimated output voltage of the storage battery by using any one of monitoring information of the battery cells which are obtained from the voltage monitoring circuits before occurrence of a communication failure in a case where the communication failure with any one of the voltage monitoring circuits occurs, and compares the estimated output voltage and an output voltage of the storage battery after occurrence of the communication failure to determine an abnormal site of the communication failure.