Abstract: A power storage system control device includes: a distribution condition output unit configured to, when a power storage system including a first power storage device and a second power storage device having a characteristic different from that of the first power storage device output power to the power system, output a distribution condition for distributing a total output command value, which is a command value obtained by summing up the power to be output by the first and second power storage devices, to the first power storage device and the second power storage device; and a command value output unit configured to output, based on the distribution condition, a first command value for commanding the power output from the first power storage device and a second command value for commanding the power output from the second power storage device to suppress overcharging and over-discharging of the power storage devices.