New regulatory certification filings in China’s C3 database have surfaced battery capacities for the upcoming iPhone 18 Pro and iPhone 18 Pro Max, and the numbers are notably uneven: the Pro Max is set for a near-10% capacity increase while the standard Pro barely moves, as reported by MacRumors.
The filings list four batteries across two regional variants. The iPhone 18 Pro is rated at 4,056 mAh for China and 4,288 mAh for the U.S., up from 3,988 mAh and 4,252 mAh respectively on the iPhone 17 Pro, increases of under 1% in both regions. The iPhone 18 Pro Max is rated at 5,391 mAh in China and 5,567 mAh in the U.S., compared to 4,823 mAh and 5,088 mAh on the iPhone 17 Pro Max battery. That works out to roughly a 500 mAh jump, or close to 10% more capacity year over year.
The filings carry battery model identifiers S2232 and S2233 for the Pro, and 2235L/2235 and 2236L/2236 for the Pro Max, with rated energy figures up to 21.751 Wh and a charge limit voltage of 4.520V. All four batteries are certified as valid through May or June 2031. The devices are not explicitly named in the filings, but the specifications align with Digital Chat Station’s report from June, which gave identical figures for the iPhone 18 Pro and noted that supply chain data from earlier in the year already pointed to the China Pro Max cell landing in the 5,000 mAh range.
The gap between U.S. and China battery ratings is not unusual and comes down to internal geometry. Apple removed the physical SIM tray from U.S. iPhones starting with the iPhone 14 lineup; iPhones sold in China have retained one. Without the tray occupying internal space, Apple can fit a slightly larger cell into the U.S. model, which is why the American versions consistently report higher capacity figures across both Pro tiers.
A modest capacity gain for the iPhone 18 Pro does not automatically mean a modest gain in battery life. Both Pro models are expected to run Apple’s A20 Pro chip, built on TSMC’s 2nm process, which is reported to be up to 15% faster and 30% more efficient than the A19 generation. The A20 chips will also use TSMC’s Wafer-Level Multi-Chip Module packaging, integrating RAM directly onto the same wafer as the CPU, GPU, and Neural Engine, a change that reduces chip size, should free up additional internal space, and cuts power draw. The C2 modem rumored for both models is expected to deliver further efficiency gains in the same vein as the C1 modem did for the iPhone 16e and the C1X for the iPhone Air. Separately, iOS 27 battery life improvements are also expected to contribute across the lineup.
