ELECTRIC VEHICLE BATTERY SYSTEM

An electric vehicle power storage system according to the present invention is provided with a plurality of power storage element rows composed of a plurality of power storage elements connected in series, and includes a parallel connecting switch configured to select the power storage element rows and connect the same in parallel, and perform connection and disconnection with respect to an electric load mounted on an electric vehicle from one power storage element row to another; a parallel connection switch controller configured to control the parallel connection switch; a vehicle power requirement calculating unit configured to calculate a vehicle power requirement; a remaining level detecting unit configured to detect a remaining level of the power storage element row; a voltage detecting unit configured to detect a voltage of the power storage element row; and a power storage system control apparatus configured to control the parallel connection switch on the basis of the vehicle power requirement, the remaining level of the power storage element row, and the voltage of the power storage element row.