A control system for an electric vehicle, comprising: an electricity storage device that performs charging and discharging of electrical power; a plurality of load devices (11 - 13) that receive supply of electrical power from the electricity storage device and perform various operations; and a control device that controls the electricity storage device and the plurality of load devices (11 - 13), wherein: when electrical power is supplied from the electricity storage device to the plurality of load devices (11 - 13), the control device regulates an amount of electrical power supplied from the electricity storage device to each of the load devices (11 - 13) and calculates a charge/discharge efficiency of the electricity storage device, characterized in that when electrical power is supplied from the electricity storage device to the plurality of load devices (11 - 13), the control device calculates a working efficiency of each of the load devices (11 - 13), and regulates the amount of electrical power supplied from the electricity storage device to each of the load devices (11 - 13), so as to enhance an overall efficiency of the electricity storage device and the plurality of load devices (11 - 13); an electric machine for propelling the electric vehicle is included in the plurality of load devices (11 - 13); and when the electrical power for driving the electric machine varies, the control device regulates the electrical power supplied from the electricity storage device to the load devices (12, 13) other than the electric machine, so as to enhance the overall efficiency with the electrical power for the electric machine having varied. an electricity storage device that performs charging and discharging of electrical power; a plurality of load devices (11 - 13) that receive supply of electrical power from the electricity storage device and perform various operations; and a control device that controls the electricity storage device and the plurality of load devices (11 - 13), wherein: when electrical power is supplied from the electricity storage device to the plurality of load devices (11 - 13), the control device regulates an amount of electrical power supplied from the electricity storage device to each of the load devices (11 - 13) and calculates a charge/discharge efficiency of the electricity storage device, characterized in that when electrical power is supplied from the electricity storage device to the plurality of load devices (11 - 13), the control device calculates a working efficiency of each of the load devices (11 - 13), and regulates the amount of electrical power supplied from the electricity storage device to each of the load devices (11 - 13), so as to enhance an overall efficiency of the electricity storage device and the plurality of load devices (11 - 13); an electric machine for propelling the electric vehicle is included in the plurality of load devices (11 - 13); and when the electrical power for driving the electric machine varies, the control device regulates the electrical power supplied from the electricity storage device to the load devices (12, 13) other than the electric machine, so as to enhance the overall efficiency with the electrical power for the electric machine having varied. when electrical power is supplied from the electricity storage device to the plurality of load devices (11 - 13), the control device regulates an amount of electrical power supplied from the electricity storage device to each of the load devices (11 - 13) and calculates a charge/discharge efficiency of the electricity storage device, characterized in that when electrical power is supplied from the electricity storage device to the plurality of load devices (11 - 13), the control device calculates a working efficiency of each of the load devices (11 - 13), and regulates the amount of electrical power supplied from the electricity storage device to each of the load devices (11 - 13), so as to enhance an overall efficiency of the electricity storage device and the plurality of load devices (11 - 13); an electric machine for propelling the electric vehicle is included in the plurality of load devices (11 - 13); and when the electrical power for driving the electric machine varies, the control device regulates the electrical power supplied from the electricity storage device to the load devices (12, 13) other than the electric machine, so as to enhance the overall efficiency with the electrical power for the electric machine having varied.