Disclosed herein are battery-free charging systems for wireless headphones that have at least one proprietary electrical contact provided to charge an on-board power source of the wireless headphone. The battery-free charging system comprises a cable having a first end and a second end, a headphone socket coupled to the first end of the cable, a connector coupled to the second end of the cable, the connector for connecting the battery-free charging system to an external power source, and circuitry coupled to the headphone socket and to the connector. The headphone socket is configured to receive the wireless headphone, to couple the at least one proprietary electrical contact to the external power source, and to allow continued use of the wireless headphone while charging. The circuitry is configured to detect an orientation of the wireless headphone within the headphone socket and provide a charging signal appropriate for the detected orientation.