A storage battery system connected to a power system and operative based on a charge/discharge request from an EMS includes: a battery management unit configured to monitor a state of the storage battery; a power conditioning system; a control device configured to receive the charge/discharge request and storage battery information supplied from the battery management unit and to control the power conditioning system based thereon; an on-site monitoring and operating device directly connected to the control device, the on-site monitoring and operating device including a display unit configured to display the storage battery information and an operation unit configured to enable an on-site charge/discharge request to the AC-DC converter to be input. The control device includes an on-site request adjustment unit configured to receive the on-site charge/discharge request and the storage battery information and to determine a charge/discharge command to the power conditioning system based thereon.