According to a recent post by the Weibo account Instant Digital, which has over 1.4 million followers, the upcoming ultra-thin iPhone 17 Air is expected to feature a battery capacity of less than 3,000 mAh.

The leak suggests Apple will introduce a new Adaptive Power Mode in iOS 26 to help the device last a full day, despite the smaller battery. Earlier rumors predicted a battery size around 2,800 mAh – significantly lower than most current flagship smartphones.

Some iPhone 12 and iPhone 13 models were the last to feature sub-3,000 mAh batteries. Though comparing battery capacities using mAh is only accurate when voltages are identical, Apple batteries generally share similar voltage levels, making these comparisons valid.

While Instant Digital has a solid track record – including accurate leaks about the yellow iPhone 14 and Titanium Milanese Loop for the Apple Watch Ultra 2 – not all its predictions have been accurate, so the information remains speculative.

A report from The Information also indicated that the iPhone 17 Air’s slim design, reportedly just 5.5mm thick, would constrain internal space, likely resulting in reduced battery capacity.

Internal Apple data reportedly shows only 60–70% of users may get a full day’s use from the iPhone 17 Air without recharging. This figure is notably lower than the 80–90% range typical of previous models.

High hopes and growing concerns

To address battery limitations, Apple is reportedly planning a new battery case accessory for the iPhone 17 Air. The company previously released Smart Battery Cases for the iPhone 11 series and MagSafe Battery Packs for the iPhone 12 and later – though the latter has since been discontinued.

These accessories not only extended battery life but also served as protective cases. If the rumors are accurate, Apple may reintroduce this type of product as an essential companion for the iPhone 17 Air, especially as it seeks to redefine smartphone design.

The iPhone 17 Air, expected to debut this fall, is rumored to be the thinnest iPhone Apple has ever created, possibly inspired by the recently launched 5.1mm iPad Pro M4.

Yet, this extreme thinness has raised concerns not only about battery life but also heat dissipation and durability. Despite advancements like Adaptive Power Mode in iOS 26, industry experts remain skeptical about the real-world battery performance, particularly for tasks like 4K video recording, gaming, or prolonged 5G use.

Additionally, the potential need for a separate battery case to achieve an “all-day experience” may increase overall costs and reduce convenience, clashing with Apple’s premium positioning.

While the iPhone 17 Air could mark a bold new chapter in Apple’s design philosophy, a sub-3,000 mAh battery – if confirmed – could pose a major challenge. Apple will need to convince both critics and everyday users that the compromises for thinness are worth the trade-off.

All eyes are now on Apple’s September event, where the iPhone 17 lineup will be officially revealed. Until then, fans are left wondering just how much Apple is willing to sacrifice for the slimmest iPhone ever – and whether those sacrifices will pay off.

Hai Phong