Heat Diffuser In Wrist Worn Wireless Power And Data System

A rechargeable wearable electronic device includes a wireless power receiver system, a device portion, and a band portion. The wireless power receiver system includes a receiver antenna, a power conditioning system, and a controller. The device portion includes a device housing containing an electronic circuitry module, which includes the wireless power receiver system and a rechargeable power source, wherein the circuitry module generates heat during wireless charging of the rechargeable power source. The band portion is for attaching the wearable electronic device to a user appendage, the band portion having a heat spreading layer of a thermally conductive material, the heat spreading layer having an inner portion within the device housing in thermal contact with the electronic circuitry module, to absorb heat from the electronic circuitry module and spread the absorbed heat to the remainder of the heat spreading layer.