Regulatory filings in China's C3 database confirm the iPhone 18 Pro Max will pack up to 5,567mAh in the US, the largest battery ever fitted inside an iPhone and a jump of nearly 500mAh over last year's model. The listings, spotted by leaker Digital Chat Station on Weibo, show the iPhone 18 Pro Max rated for 5,391mAh in China and 5,567mAh in the US. That compares with 4,823mAh and 5,088mAh on the iPhone 17 Pro Max.
The standard iPhone 18 Pro gets a more modest increase: 4,056mAh in China and 4,288mAh in the US, up from 3,988mAh and 4,252mAh on its predecessor. The gap between China and US capacities comes down to the SIM tray. Apple has sold US iPhones as eSIM-only since the iPhone 14 lineup, freeing internal space for a slightly larger battery in American units.
That trend continues with the 18 Pro series. The bigger story is how much Apple is widening the gap between its two Pro models. The Pro Max gains roughly 12% more capacity year over year, while the standard Pro inches up just 1-2%.
Paired with the 2nm A20 Pro chip expected to debut in the lineup, the Pro Max could deliver a dramatic real-world battery life improvement. The certification filings cover battery models S2232 and S2233 for the iPhone 18 Pro and 2235L/2235 and 2236L/2236 for the Pro Max. They list rated energy figures up to 21.751Wh with a 4.520V charge limit, and show all four batteries as valid through May or June 2031.
Digital Chat Station's latest leak matches his own report from June, which gave identical figures for the iPhone 18 Pro. In a separate post, he said supply chain information from months earlier had already pointed to the China Pro Max model landing in the "5,000mAh" range, and suggested the 5391mAh cell paired with the 2nm chip could deliver a noticeable battery life improvement.
The iPhone 18 Pro and Pro Max are expected to launch in September alongside Apple's first foldable iPhone. Other rumored upgrades include a smaller Dynamic Island, a variable aperture main camera, and the C2 modem for models sold outside the US.
