A photograph shared on the Korean platform Naver appears to show the battery cell for Apple’s upcoming iPhone 18 Pro Max, with regulatory text listing a capacity of 5,391mAh. If genuine, the image would reinforce earlier claims that the larger Pro Max model is in line for one of the more substantial battery increases in recent iPhone generations.
- Photos shared on Naver on August 10 appear to show an iPhone 18 Pro Max battery labeled 5,391mAh
- The capacity matches Chinese regulatory filings from July 6 spotted by Digital Chat Station
- The iPhone 18 Pro Max is rumored to reach 5,567mAh in eSIM-only U.S. models
- The standard iPhone 18 Pro is expected to see a minimal battery increase of less than 2 percent
- Apple has not confirmed any specifications; official announcement expected in September
The images were posted on August 10 by the user Yeuz1122, according to AppleInsider. Multiple angles show a black rectangular battery bearing the Apple logo and printed regulatory markings. Shots shared from the front, back, and top section reveal a small printed text block near the connector that lists the 5,391mAh figure, along with additional compliance text typical of Apple battery cells.
That capacity aligns with ratings that appeared in Chinese regulatory filings one month earlier. On July 6, entries in China’s C3 certification database spotted by the Weibo leaker Digital Chat Station listed the iPhone 18 Pro Max at 5,391mAh for models with a physical SIM tray and 5,567mAh for the eSIM-only version sold in the United States. The iPhone 17 Pro Max, by comparison, carries a 4,823mAh cell in physical-SIM markets and 5,088mAh in the U.S. If the filings prove accurate, the new Pro Max would represent a year-over-year increase of roughly 12 percent in physical-SIM markets and about 10 percent in the U.S.
The gains appear to be concentrated in the larger model. The same July regulatory filings indicated that the standard iPhone 18 Pro will see a far smaller bump, rising to just 4,056mAh in physical-SIM markets and 4,288mAh in the U.S. That would be less than a 2 percent increase over the iPhone 17 Pro in either configuration, suggesting Apple is using the additional internal space in the Pro Max chassis primarily to expand battery volume rather than distributing it evenly across both sizes.
Apple has used eSIM-only designs in the United States since the iPhone 14 lineup, freeing internal space that would otherwise be occupied by a physical SIM tray. Several other countries, including Canada, Japan, and Mexico, moved to eSIM-only starting with the iPhone 17 generation. The 5,391mAh figure shown in the leaked photograph aligns with the physical-SIM variant listed in the July regulatory filings, according to MacRumors.
The divergence between the Pro and Pro Max battery upgrades would widen the already noticeable gap between the two models. While both devices typically share processors, displays, and camera systems, the Pro Max has historically offered longer battery life due to its larger physical size. A substantially larger battery in the 18 Pro Max would extend that advantage further.
For users, a roughly 10 to 12 percent increase in raw battery capacity would mark one of the larger year-over-year jumps for a Pro Max model in recent generations. Whether that translates into a proportional increase in real-world battery life depends on factors Apple controls but has not disclosed, including the power efficiency of the next-generation processor and any display changes that might affect power draw.
With the iPhone 18 Pro range expected to debut in September, the volume of component leaks is likely to increase in the coming weeks. The leak arrives at a point in the annual cycle when photographic evidence of upcoming iPhone components typically surfaces in greater volume. Supply chain photography has grown increasingly difficult to verify independently, as generative image tools have made it easier to fabricate realistic-looking component photos. The fact that the 5,391mAh figure matches a prior regulatory filing, however, lends the images more credibility than a standalone leak would carry.
Apple has not confirmed any specifications ahead of the official announcement. Readers should treat all leaked component images as unverified until the company formally unveils the devices.