So many rumours have been going around about the upcoming iPhone 18 Pro and 18 Pro Max – they just popped up on China’s 3C certification site, giving everyone an early look at their battery specs. Apple has not said anything official yet, but this new leak points to bigger batteries for both the Pro and Pro Max. The Pro Max variant will especially be getting a bigger boost, as per the leaks.
An interesting detail about the upcoming devices is that Apple will be keeping its habit of giving US iPhones slightly bigger batteries than those sold internationally. They have done this since the iPhone 14, and it does not look like they are stopping now.
3C Certification reveals bigger batteries
A source known as Digital Chat Station spotted two battery model numbers on the 3C site—almost definitely the next Pro models. Here’s the breakdown:
iPhone 18 Pro
- China: 4,056mAh
- US: 4,288mAh
Both are a bit bigger than the batteries rumoured for the iPhone 17 Pro.
iPhone 18 Pro Max
- China: 5,391mAh
- US: 5,567mAh
That’s a sizeable upgrade over what we’ve heard about the 17 Pro Max.
But why the size difference between US and international models?
It comes down to the SIM card tray. Starting with the iPhone 14, Apple ditched the physical SIM slot in US models and went fully eSIM. That leaves more room inside for a larger battery—so if you’re in the US, you get a little more juice.
Besides the actual battery sizes, the certification lists up to 21.751Wh of energy, a 4.520V charging cap, and approval that lasts through 2031.
iPhone 18 series: Launch timeline
Apple is expected to show off the iPhone 18 Pro, Pro Max, and the first foldable iPhone at their event in September 2026. There’s talk that the regular iPhone 18 and iPhone 18e—a more affordable model—might show up separately in spring 2027. So, Apple might spread out their releases for the first time.
Of course, all this comes from leaks and certifications, not from Apple directly. We’ll have to wait for the official reveal to know for sure.
