Leak reveals iPhone Ultra's foldable battery capacity

A new regulatory filing may have revealed exactly how big the battery inside Apple's first foldable iPhone will be, just weeks ahead of the device's rumoured September announcement.

According to leaker Digital Chat Station's post on Weibo, the battery manufacturer of Apple has recently registered two new batteries with capacities of 1,921mAh and 2,962mAh, respectively, resulting in a combined capacity of 4,883mAh.

However, according to the leaker, the wider estimates made by the supply chain still suggest that the figure is slightly broader at 4,800 to 5,000mAh, suggesting that the exact figure is not finalised yet.

iPhone Ultra's new battery leaks

The two-battery figure indicates the use of split-battery technology in the device, which is an industry-standard technique used in foldable devices with the book-type folding method.

This suggests that the iPhone Ultra will end up in between its closest rivals rather than be ahead of them, as the Galaxy Z Fold 7 from Samsung features a battery with a 4,400 mAh capacity, while the Pixel 10 Pro Fold from Google will feature a 5,015 mAh battery, compared to the previous 4,650 mAh one.

That positions Apple's debut foldable as a modest step up from Samsung but still short of Google's current leader, a notable detail given how much attention Apple's battery efficiency claims typically draw at launch.

Individual leaks are giving a clearer view of the battery capacities in September's line of devices. For the iPhone 18 Pro, its rumoured battery capacity stands at 4,288mAh for the eSIM variant and 4,056mAh for the physical SIM version, with increases of 36mAh and 68mAh compared to last year’s iPhone 17 Pro.

The larger and more interesting variant is the iPhone 18 Pro Max, which is speculated to have a battery capacity of 5,567mAh and 5,391mAh based on whether it has the eSIM or physical SIM variant, marking an increase of up to 568mAh, making it the largest iPhone battery ever made by Apple.

Of course, the actual battery life depends on many factors, including how different a design can be from a regular iPhone, especially when it comes to a foldable one.