Foreign Object Detection Testing for Wireless Chargers

In an embodiment, a method for performing foreign object detection (FOD) testing of a wireless power transmitter includes: placing a foreign object (FO) between the wireless power transmitter and a wireless power receiver; beginning to wirelessly transmitting power from the wireless power transmitter towards the wireless power receiver; a predetermined amount of time after beginning to wirelessly transmit power, measuring an FO temperature indicative of a temperature of the FO, a transmitter temperature indicative of a temperature of the wireless power transmitter, and a receiver temperature indicative of a temperature of the wireless power receiver; determining a weighted average temperature based on the measured transmitter temperature and the measured receiver temperature; and when a difference between the measured FO temperature and the weighted average temperature is higher than a threshold temperature, asserting an error flag indicative that the FOD test failed.