LOW POWER PING TRANSITION TO WIRELESS POWER RECEIVER MODE

An electronic device selectively operable in a wireless power receiver mode to receive power from a wireless power transmitter and in a wireless power transmitter mode to transmit power to an accessory can include a wireless power transfer coil; a rectifier coupled to the wireless power transfer coil and operable in the wireless power receiver mode to convert an AC voltage induced in the wireless power transfer coil by a wireless power transmitter to a DC voltage for use by the electronic device; an inverter coupled to the wireless power transfer coil and operable in the wireless power transmitter mode to convert a DC voltage to an AC voltage applied to the wireless power transfer coil; and controller and communication circuitry that, responsive to detecting one or more object detection pings from a wireless power transmitter, activates the wireless power receiver mode.