A flexible conveyor belt has a plurality of transverse rods on which a plurality of links are mounted for rotational and longitudinal movement on the rods. An embodiment of the stimulator comprises a pulse generator to provide a baroreflex stimulation signal through an electrode, and a modulator to modulate the baroreflex stimulation signal based on a circadian rhythm template. According to a first method, a parent node withdraws address values of child nodes that do not transmit a hello message for a predetermined period of time. A controller controls the constant voltage charge controller to perform the constant voltage charging operation during a period from when the charge voltage reaches a fully charged voltage to when the charge current decreases to a charge completion current.