The iPhone 18 Pro Max is emerging as one of Apple’s most closely watched battery upgrades, with a new leak suggesting that the eSIM-only version could approach 5,500 mAh. If accurate, it would mark a notable shift in how Apple uses internal space in its largest flagship.
The reported split between regional variants is the key detail. According to the leak circulating on Weibo, the version for the US, which is expected to drop the physical SIM slot entirely, could carry a 5,425mAh battery, while the Europe and global model with a nano-SIM tray may be limited to 5,235mAh.
Leaked iPhone 18 Pro and iPhone 18 Pro Max battery capacities
| Model | EU | US |
|---|---|---|
| iPhone 17 Pro | 3,998mAh | 4,252mAh |
| iPhone 17 Pro Max | 4,823mAh | 5,088mAh |
| iPhone 18 Pro | 4,056mAh | 4,288mAh |
| iPhone 18 Pro Max | 5,235mAh | 5,425mAh |
The difference is tied to hardware layout. A physical SIM slot takes up room inside the chassis, so an eSIM-only design can free up space for a larger battery pack.
That design change would also explain why the jump looks more aggressive in the United States than in markets that still rely on a removable tray. Compared with the iPhone 17 Pro Max, the European version would rise by 412mAh, or about 8.5 percent, while the US version would increase by 337mAh, or roughly 6.6 percent.
The same leak also outlines the standard iPhone 18 Pro. In Europe, its battery is said to move from 3,998mAh on the iPhone 17 Pro to 4,056mAh, while the US variant would edge up from 4,252mAh to 4,288mAh.
That keeps Apple’s regional battery strategy consistent across the Pro lineup. Markets that still receive a nano-SIM tray appear to get slightly smaller batteries than markets moving fully to eSIM.
The rumor also aligns with earlier comments from tipster Digital Chat Station, who previously suggested that the iPhone 18 Pro Max would finally cross the 5,000mAh mark. If the new figures hold, the model would move well beyond that threshold.
Battery capacity is likely to matter even more on the next Pro Max model because it is also linked to the A20 Pro 2nm chip. Combined with Apple’s software optimization, that chipset could improve efficiency alongside the larger battery.
On paper, a 5,425mAh battery would put the iPhone 18 Pro Max in a stronger position against competing flagships. Apple has often lagged Android rivals in raw battery numbers, so a larger pack would narrow one of the most visible gaps in the spec sheet.
Samsung is part of that comparison. The Galaxy S26 Ultra is currently said to match the iPhone 17 Pro Max in battery capacity on paper, although real-world endurance usually falls a little short.
Looking ahead, the Galaxy S27 Ultra is also rumored to reach 5,500mAh. If that happens, the premium flagship race would become even tighter, especially since Samsung has not raised the Ultra battery capacity since the Galaxy S20 Ultra in 2020.
Chinese brands are already operating at a different scale. Several of them have pushed flagship batteries much higher, with 7,500mAh starting to look common in some models.
Among the devices noted for strong battery testing are the Xiaomi 17 Pro Max, Oppo Find X9 Pro, and OnePlus 15. Those phones are reported to outperform recent iPhones and Galaxy models in endurance tests.
For now, the iPhone 18 Pro Max battery story remains a leak rather than an official announcement. The iPhone 18 series is expected to arrive in September 2026, which still leaves room for Apple’s plans to change before launch.
