When not in use, store energy at a low speed, and, during the injection, the electric syringe for delivering energy at a high speed is disclosed. For rapid power delivery to the motor of the syringe, energy can be stored in the energy storage device of the high response of the capacitor and the like. In certain embodiments, the wires for connecting the electric syringe to a power supply device, the load current and voltage applied to the wire is in relatively low, can be relatively size is small and inexpensive.