Control device, control system, and control method

A control system including a control device provided in a power consumer including a DC power supply, a load, and a battery capable of storing power from the DC power supply, and controlling the load, and a device capable of operating the plurality of load, wherein

• the control device comprises:
• a detection unit configured to detect a remaining amount of the battery;
• and
• a load control unit configured to control a degree of power consumption of the load according to the remaining amount of the battery detected by the detection unit, at a time of a self-sustained operation in which power from an electric power system is not supplied to the load, and to transmit an instruction related to control of the degree of the power consumption of the load to the device, and
• the device comprises:
• a transmission unit configured to transmit an operation instruction to the load, the operation instruction corresponding to the instruction related to the control of the degree of the power consumption of the load.