iPhone 18 Pro Max battery leak: Apple could pack its biggest-ever battery in the flagship; Check battery size and sim tray details

Apple's iPhone 18 Pro Max is still months away, but details about what may be inside it are already beginning to surface. A set of regulatory filings reportedly spotted in China suggest the next Pro Max could carry the largest battery Apple has ever shipped in the model, with American buyers potentially in line for an even bigger cell than the rest of the world.

None of this is confirmed. Apple has not said anything officially, and the filings have not been independently verified. But regulatory databases of this kind have historically been a reliable early indicator of battery specs, so the numbers are worth paying attention to.

What the filings reportedly show


The information comes from tipster Digital Chat Station, who reportedly spotted two device listings on China's Compulsory Certification database, commonly referred to as CCC. The listings do not name the iPhone 18 Pro or Pro Max directly, but the battery model numbers are believed to correspond to Apple's upcoming flagship pair.

According to the filings, the US version of the iPhone 18 Pro Max is reportedly tipped to carry a 5,567mAh battery. The international variant, by comparison, is said to come in at 5,357mAh. The documents also reportedly list a rated energy capacity of 21.751Wh, a charging voltage ceiling of 4.520V, and regulatory validity running through May or June 2031.

The standard Pro is not left out either. The iPhone 18 Pro is reportedly tipped to carry a 4,288mAh battery in the US against 4,056mAh internationally.

How this compares to what came before

To put those numbers in context, the current iPhone 17 Pro Max reportedly ships with a 5,088mAh cell in the US and 4,823mAh internationally. If the leaked figures hold, the Pro Max would be getting a jump of roughly 480mAh on the American version alone, which is a more significant leap than Apple has made between recent generations.

The Pro tells a similar story. The iPhone 17 Pro reportedly carries 4,254mAh in the US and 3,988mAh elsewhere, meaning the 18 Pro would be a modest but consistent step up on both fronts.

Why the US always gets more

The regional difference is not new, and the reason behind it is fairly straightforward. Since the iPhone 14 in 2022, Apple has shipped its US models without a physical SIM card tray, relying entirely on eSIM technology instead. Removing the tray frees up a small but meaningful amount of internal space, and Apple has used that space each year to fit a slightly larger battery in American units.

International models continue to carry a physical SIM tray, which limits how much room is available for the battery. The result is a consistent gap that has grown slightly wider with each generation.

What else is expected from the iPhone 18 lineup

The iPhone 18 series is widely expected to be announced in September 2026. Reports suggest the launch could include the iPhone 18 Pro, iPhone 18 Pro Max, and Apple's long-rumoured first foldable iPhone. The standard iPhone 18 and a new iPhone 18e are reportedly tipped to arrive in spring 2027.

Apple has not confirmed any of this.