iPhone 18 Pro Max Might Arrive With Apple's Biggest Smartphone Battery to Date, Latest Leak Suggests

Apple's iPhone 18 Pro Max may arrive with a significantly larger battery than its predecessor, if a new leak is accurate. The latest information indicates that battery capacity could vary between regional variants, with the eSIM-only model tipped to receive the biggest cell. An earlier leak also suggested modest increases in battery capacity for the iPhone 18 Pro. If the reported specifications are correct, the eSIM version of the iPhone 18 Pro Max would be the first iPhone to feature a battery capacity exceeding 5,400mAh.

Apple's iPhone 18 Pro Max Battery Capacity Leaked Ahead of Launch

A post shared on Weibo by Duoge Internet Technology (translated from Chinese) claims the iPhone 18 Pro Max will ship with a 5,425mAh battery in markets where Apple offers only eSIM support. In countries that continue to receive a physical nano-SIM tray, the handset is said to include a 5,235mAh battery instead. The report attributes the difference to the extra internal space made available by removing the SIM card slot.

An earlier leak hinted at the expected battery capacities of the iPhone 18 Pro. The physical SIM version is tipped to pack a 4,056mAh battery, while the eSIM model could carry a slightly larger 4,288mAh unit.

For comparison, the iPhone 17 Pro reportedly features batteries rated at 3,998mAh and 4,252mAh in the physical SIM and eSIM variants, respectively. The iPhone 17 Pro Max is said to include a 4,823mAh battery in markets with a SIM tray and a 5,088mAh battery where it is sold as an eSIM-only device.

Based on the leaked capacities, the Pro Max appears set for a larger battery upgrade than the standard Pro model. The smartphone is also expected to debut with Apple's rumoured A20 Pro processor, which is believed to use a 2nm manufacturing process. A higher battery capacity combined with a more efficient chipset could improve battery endurance, though the final result will also depend on software tuning and display power consumption.

Samsung's Galaxy S26 Ultra currently offers a battery comparable in size to the iPhone 17 Pro Max, while rumours suggest the Galaxy S27 Ultra could increase capacity to 5,500mAh. Chinese flagship phones, including the Xiaomi 17 Pro Max, Oppo Find X9 Pro and OnePlus 15, already use batteries around the 7,500mAh mark, and recent industry reports indicate that some Android flagships may approach 9,000mAh capacities before the end of the year.

Apple is widely expected to unveil the iPhone 18 lineup in September 2026. Until the company officially announces the devices, the leaked battery specifications remain unverified.