In an embodiment, a method includes wirelessly transmitting power using a transmitter LC tank of a wireless power transmitter, wirelessly receiving power from the transmitter LC tank using a receiver LC tank of a wireless power receiver, interrupting wirelessly transmitting power for a slot period, during the slot period, measuring a receiver signal associated with the receiver LC tank, transmitting receiver data based on the measured receiver signal to the wireless power transmitter, determining a power loss associated with the wirelessly transmitting power based on the measured receiver signal and detecting a metallic object based on the determined power loss.