The upcoming iPhone 18 Pro Max will be equipped with a nearly 12% larger battery compared to the iPhone 17 Pro Max, according to an apparent leak. An alleged photo of a battery pack for a Chinese model lists a capacity of 5,391 mAh, up from 4,823 mAh for the equivalent iPhone 17 Pro Max battery. The photo was shared on the Korean platform Naver today, but it supposedly originated from the Chinese social media platform Weibo.

For the U.S. model, which lacks a SIM card tray and thus has more internal space, the Naver post claims a 5,567 mAh capacity. The equivalent iPhone 17 Pro Max has a 5,088 mAh battery, representing a nearly 10% increase year‑over‑year. The smaller iPhone 18 Pro, however, shows only a marginal improvement: 4,288 mAh versus 4,252 mAh in the U.S., a change of less than 1%.

The capacity differences arise because Apple continues to include a physical SIM tray on models sold outside the U.S., while U.S. (and several other) models are eSIM‑only. Removing the tray allows Apple to fit a slightly larger battery into each device.

These figures, corroborated by a regulatory database entry last month,root the leak’s credibility and confirm the trend toward larger batteries in the next‑generation Pro line.