iPhone 18 pro Max leak reveals exact battery capacities

Apple is preparing a massive battery upgrade for its upcoming flagship, according to the latest industry leaks. The iPhone 18 Pro Max is rumored to feature the largest battery capacity ever seen on a standard, non-folding iPhone—even surpassing its primary Android rivals.

The leak reveals a split in capacities depending on the SIM configuration, following a design choice Apple has leaned into over recent generations.

The Leaked Numbers: eSIM vs. Physical SIM

Because physical SIM trays occupy valuable physical space inside a smartphone chassis, Apple can fit a slightly larger cell into models that rely purely on eSIM technology.

Rumored battery figures suggest the iPhone 18 Pro Max will see a modest capacity increase over the iPhone 17 Pro Max. The eSIM-only version, expected for markets like the US, is tipped to pack a 5,425 mAh battery, up 337 mAh from the 5,088 mAh cell in the 17 Pro Max. The physical SIM slot version for global markets is rumored to have a 5,235 mAh battery compared to 4,823 mAh in the previous model.

Beating the Android Competition

iPhones have historically optimized battery performance through highly efficient chip architecture rather than raw battery volume. However, if these numbers hold true, Apple is shifting strategy to offer massive raw capacities.

At a rumored 5,425 mAh for the top-end variant, the iPhone 18 Pro Max will officially pack a larger physical cell than the Samsung Galaxy S26 Ultra, which currently sits at a steady 5,000 mAh.

Why This Matters for Upgraders

Massive Year-Over-Year Jump: A 412 mAh generation-over-generation increase for the physical SIM variant is one of the largest single-generation jumps Apple has ever made.

Better Thermal Management: A larger physical capacity means less strain on the battery cycles during heavy tasks like AI processing and mobile gaming.

Note: As with all pre-release supply chain rumors, these specifications are highly plausible but remain unconfirmed until Apple’s official announcement.