A residential electric power storage system includes a lead-in wire, a distribution line, an electric power storage device, a voltage sensor sensing a voltage of the lead-in wire, a current sensor sensing a current charged to the electric power storage device through the distribution line and an electric power adjustment unit adjusting electric power charged to the electric power storage device through the distribution line; and a controller controlling the electric power adjustment unit. If the lead-in wire has voltage smaller than a threshold voltage, the controller controls the electric power adjustment unit to match the current that is charged to the electric power storage device to a command value to provide current control, whereas if the lead-in wire has voltage larger than the threshold voltage, the controller controls the electric power adjustment unit to match the voltage of the lead-in wire to a command value to provide voltage control.