Lately, a number of iPhone users have reported an unusual phenomenon: their newly - acquired iPhone models, such as the iPhone 16 Pro Max and iPhone 15, have exhibited battery swelling during flights. However, the batteries return to their normal state after the aircraft lands.

One user recounted that during a flight, a noticeable gap emerged between the back panel and the main body of their iPhone 16 Pro Max. This gap vanished once the plane touched down, and it did not reappear on subsequent flights.

Another user shared that their iPhone 15 suffered from battery swelling on two separate flights. Fortunately, the problem was resolved after having the battery replaced.

Industry analysts speculate that this issue might be linked to the inherent properties of lithium batteries. The low air pressure inside the aircraft cabin can cause the gas within the battery to expand, which in turn leads to the swelling of the battery. Although the battery's physical appearance returns to normal after landing, there are still latent safety risks that users should be aware of.