An implantable stimulator(s) with at least two electrodes, which is small enough to have the electrodes located adjacent to a cavernous nerve(s) or other nerve(s) innervating the reproductive organs, uses a power source/storage device, such as a rechargeable battery. Periodic recharging of such a battery is accomplished, for example, by inductive coupling with an external appliance. The small stimulator provides means of stimulating a nerve(s) when desired, without the need for external appliances during the stimulation session. When necessary, external appliances are used for the transmission of data to and/or from the stimulator(s) and for the transmission of power. In a preferred embodiment, the system is capable of open-and closed-loop operation. In closed-loop operation, at least one implant includes a sensor, and the sensed condition is used to adjust stimulation parameters.