A power transmission pad is configured to provide wireless power transmission to a receiving device where the receiving device is orientation-free relative to the pad. The pad functions as a transmitter and is magnetically “hot”, meaning the pad generates a magnetic field when powered on. The receiving device, such as a cell phone, tablet, or other portable electronic device, is placed within the magnetic field for the purpose of charging the device battery. In contrast to conventional wireless battery charging systems, there are no restrictions on the orientation of the receiving device relative to the pad. The power transmission pad includes a sweep frequency generator for generating power transmissions across a frequency spectrum. An optimal frequency is determined for maximum energy transfer to the receiving device, and the sweep frequency generator is locked to the determined optimal frequency.