An example system charges an electronic device using wirelessly transmitted radio-frequency power (RF) waves. The system includes the electronic device with one or more movable arms. At least one movable arm includes a receiving antenna element. The system further includes a charging pad that includes a housing. The housing includes at least one guiding contour on a surface that is configured for align a position of the electronic device on the surface of the housing. The charging pad further includes transmitting antenna elements that are selectively activated to transmit radio-frequency power waves to the receiving antenna element of the electronic device. The system also includes a transmitter controller integrated circuit (IC) configured to selectively activate a respective transmitting antenna element of the transmitting antenna elements. Activating the respective transmitting antenna element causes transmission of the radio-frequency power waves to the receiving antenna element of the electronic device.