Apple’s upcoming iPhone 17 Air is shaping up to be its slimmest and most radical redesign in years, and new leaks offer a closer look at one of the most critical components inside: the battery.
According to images shared by leaker Majin Bu, the iPhone 17 Air will feature a 2,900 mAh L-shaped battery in a metal casing, significantly smaller than the 3,651 mAh cell found in the iPhone 16. That sharp drop in capacity comes down to the phone’s ultra-thin design, which is expected to measure just 5.5mm at its thinnest point—making it the slimmest iPhone Apple has ever built.
The metal casing, first used in the iPhone 16 Pro, does more than just protect. It plays a key role in dispersing heat, helping with thermal management and potentially speeding up charging. It also strengthens the battery against accidental punctures or bending, which matters even more in a device this thin, where components are packed tightly together.
Even with the smaller battery, Apple is counting on its A19 chip and iOS 26 to help keep battery life in check. The A19 is expected to be more power-efficient than any chip before it, and iOS 26 introduces Adaptive Power Mode—an intelligent energy management feature that dials back background activity and performance when needed.
Still, that may not be enough for everyone. Apple’s internal testing reportedly shows that only 60 to 70 percent of users could get through a full day without needing to recharge. That’s down from the usual 80 to 90 percent on other models. To help with this, Apple is said to be working on a dedicated battery case for the iPhone 17 Air. It would be the first since the MagSafe Battery Pack, offering an optional boost for days when you know you’ll need it.
The iPhone 17 Air will also use the same adhesive system introduced with the rest of the iPhone 17 lineup, which lets you remove the battery using a low-voltage electrical current. That should make repairs easier and more accessible, in line with Apple’s slow shift toward more repair-friendly designs.
Set to replace the iPhone 16 Plus in the 2025 lineup, the iPhone 17 Air is expected to keep a similar 6.6-inch display but will drop the ultrawide camera to make room for the slimmer body. Apple is clearly making trade-offs to push the boundaries of design—but whether it pulls it off will depend on how well the A19 chip and iOS 26 make up for that smaller battery.
(via Majin Bu)
