For this year’s trio of new iPhones, Apple has allegedly switched to thicker copper wire coils that have lower resistance, resulting in faster, more efficient Qi wireless charging.
Apple brought wireless charging to the iPhone family last year with the release of the iPhone X, iPhone 8 and iPhone 8 Plus models. These smartphones are outfitted with thinner coils made from the ferrite polymer composite material (FPC) which has higher resistance than copper.
The copper wire coil resistance is so small that it can offset the thermal effects generated by the increase in power, basically permitting Apple engineerings to increase power to the coil without overheating it, which would result in faster and more efficient wireless charging.
It’s unclear if the solution goes beyond 7.5W charging that the current iPhone models support (top-end Samsung devices feature 10W wireless charging).
We should find that out sooner than later because Apple’s big fall reveal is due in September and one of the announcements we’ll be keeping a close eye on is any news regarding wireless charging advanced, including availability of that elusive multi-device AirPower charging mat.