In the present invention, a cordless inductively coupled electrosurgical instrument is adapted to receive electrosurgical energy from a specially designed trocar or trocar adapter. In one embodiment of the present invention, an electrosurgical instrument includes a handle, an elongated tube and an electrosurgical end effector. The handle may include an actuator such as a trigger which is operatively connected to the end effector through the elongated tube. The elongated tube may be, for example, a closure tube which is adapted to close the end effector when the handle actuator is moved. The electrosurgical end effector is adapted to apply electrosurgical energy to biological tissue in order to effect treatment of the tissue. The elongated closure tube includes one or more inductor coils adapted to couple electrosurgical energy to the end effector. The one or more inductor coils are electrically connected to the end effector through one or more electrical conductors.