iPhone 18 Pro Max’s biggest battery capacity reportedly revealed

The upcoming iPhone 18 Pro Max will feature a battery nearly 12% larger than the iPhone 17 Pro Max, according to an apparent leak.

A purported photo of a battery for a Chinese model of the iPhone 18 Pro Max with a SIM card tray lists a capacity of 5,391 mAh, compared to 4,823 mAh for the equivalent iPhone 17 Pro Max battery. The photo was shared today on Korean platform Naver, but is believed to have come from Chinese social media platform Weibo.

The identical 5,391 mAh capacity appeared in a regulatory database last month, so the capacity seems increasingly accurate.

For the US model of the iPhone 18 Pro Max, in which the lack of a SIM card tray provides more space for a slightly larger battery, Naver’s post claims it will have a capacity of 5,567 mAh. The equivalent iPhone 17 Pro Max has a 5,088mAh battery, which would represent a nearly 10% year-over-year increase.

Based on this leak, it appears that the significant battery life gains won’t extend to the smaller iPhone 18 Pro. In the US, the device will apparently have a 4,288 mAh battery, which would be less than a 1% increase over the iPhone 17 Pro’s 4,252 mAh battery in that country. The iPhone 18 Pro Max is rumored to be thicker than the iPhone 18 Pro, which could help explain the difference.

All alleged iPhone 18 Pro battery capacities are listed in the table below.

iPhone 18 Pro

iPhone 18 Pro Max

Capacities differ by region as Apple has continued to include a SIM tray on iPhones sold in some countries outside the United States, while US models have been eSIM-only since the iPhone 14 line. Without a physical tray taking up internal space, Apple can fit a slightly larger battery into the eSIM-only version of each device.

Starting with iPhone 17 Pro and iPhone 17 Pro Max, the SIM card tray is also removed on models sold in Canada, Japan, Mexico, Saudi Arabia, United Arab Emirates, and a few other countries and territories.