The upcoming iPhone 18 Pro Max is rumored to feature one of the largest batteries ever installed in an iPhone, signaling a notable shift in the device’s power capacity.
According to the leak, the Nano SIM version would house a 5,235 mAh battery, while the eSIM‑only model could contain a 5,425 mAh unit. These figures represent increases of roughly 8.5 % and 6.6 % over the iPhone 17 Pro Max’s 4,823 mAh and 5,088 mAh batteries, respectively.
In contrast, the iPhone 18 Pro is expected to see a modest rise of only about 1.5 % and 0.8 % across its two variants, highlighting the Pro Max’s focus on endurance. The projected capacity would also outstrip many competitors, such as the Samsung Galaxy S26 Ultra, which uses a 5,000 mAh battery.
Apple’s battery sizes have risen steadily over recent generations: 4,352 mAh (iPhone 13 Pro Max), 4,323 mAh (iPhone 14 Pro Max), 4,441 mAh (iPhone 15 Pro Max), 4,685 mAh (iPhone 16 Pro Max), and 4,823 mAh/5,088 mAh for the iPhone 17 Pro Max’s Nano SIM and eSIM models.
The credibility of the new figures remains uncertain, as the leak originates from an unverified source and the supporting image has been removed. Without a track record, the information should be treated with caution.
Nevertheless, earlier speculation from a different insider projected battery capacities in the 5,000 mAh to 5,200 mAh range for the iPhone 18 Pro Max, lending some consistency to the latest numbers.
Looking ahead, the forthcoming iPhone Ultra is expected to carry an even larger battery, estimated at 5,500 mAh to 5,800 mAh, positioning it among the most sizable smartphone batteries on the market.
If confirmed, the expanded capacity could translate into noticeably longer usage times, though it may also contribute to a higher price point for the flagship model.
