Insider Max Weinbach in a video on the YouTube channel EverythingApplePro said that the iPhone 13 series smartphones will be equipped with enlarged wireless charging coils. This change is supposed to be useful for reverse (reversible) wireless charging.
The fact that the iPhone 12 will have the function of recharging other devices from the body of the smartphone using Qi technology was reported even before the presentation of the series in the fall of 2020. This is confirmed by the documents of the mobile device, registered with the US Federal Communications Commission.
In addition, in early June, Bloomberg announced work on the iPad Pro with a glass body and wireless charging.
In February, Weinbach announced via EverythingApplePro that the iPhone 13 will receive a more powerful set of magnets on the back for MagSafe technology. Perhaps this is another reason for the increase in coil size – this is how engineers are trying to compensate for the reinforced magnets.