iPhone 18 Pro Max battery leaks suggest capacity upgrade

The most recent unverified battery claims for the iPhone 18 Pro Max are the most ambitious to date. According to alleged certification data, Apple’s upcoming flagship might include a 5,567mAh battery for its eSIM-only variant and a 5,391mAh cell for the version with a physical SIM.

If accurate, this would make it the largest battery ever installed in an iPhone. However, this remains unconfirmed. Earlier leaks suggested significantly lower figures, and Apple has yet to officially comment on the highly anticipated device.

The theory behind the varying capacities is straightforward. By eliminating the physical SIM tray in certain regional markets, Apple can free up internal space to accommodate a larger battery.

This regional split is already anticipated in the iPhone 17 Pro Max, with the eSIM-only version reportedly having about 5,088mAh, and the physical-SIM version around 4,685mAh.

However, the new leaks directly contradict earlier reports. In June, prominent Weibo leaker Digital Chat Station suggested a much more conservative 5,000mAh for the physical-SIM model and around 5,100mAh to 5,200mAh for the international versions.

This discrepancy highlights the volatility of pre-launch rumors, which can often reflect different prototype units or misidentified models.

Raw milliamp-hours are just one aspect of overall smartphone battery life. The iPhone 18 Pro Max is anticipated to feature the rumored A20 Pro chip, which is said to be manufactured using TSMC’s cutting-edge 2nm process.

Supply-chain expectations suggest the new processor will deliver roughly 15 percent faster CPU performance and up to 30 percent better power efficiency than the A19 Pro. Along with iOS 27 and a new cellular modem, these hardware optimizations will determine actual battery life just as much as the physical cell size.

Leakers continue to fiercely debate the possible hardware trade-offs. Although Ice Universe previously stated that the iPhone 18 Pro Max would keep the same thickness of 8.75mm as its predecessor, newer rumors suggest that the Pro models might be between 9.9mm and 10.9mm thick.

Another leak from Instant Digital indicates the phone may weigh more than 240 grams, so users might actually feel the impact of a larger battery in their pocket.

For consumers planning their next upgrade, the exact battery numbers remain too unreliable to be taken as fact.

Apple is expected to unveil the iPhone 18 Pro lineup in September 2026. Until the official regional specifications are released, the central question remains whether Apple can deliver a large battery and an efficient chip without turning its premium flagship into a heavy brick.

iPhone 18 Pro Max battery leaks suggest massive capacity upgrade