The Leak
Three photos purportedly showing the iPhone 18 Pro Max’s actual battery have surfaced from China, and one clearly displays a capacity of 5,391 mAh. This aligns with earlier rumors and confirms the physical SIM model (which China gets) will carry this capacity. The eSIM-only variant is expected to pack a larger 5,567 mAh cell.
Context: From Rumor to Reality
Back in early July, we heard conflicting figures: 5,425 mAh (eSIM) / 5,235 mAh (physical SIM), then revised to 5,567 mAh (eSIM) / 5,391 mAh (physical SIM). The leaked photos match the latter—and since China requires physical SIM slots, the 5,391 mAh figure fits perfectly.
How Big Is the Jump?
- iPhone 17 Pro Max: ~4,850 mAh (estimated)
- iPhone 18 Pro Max (physical SIM): 5,391 mAh → ~11% increase
- iPhone 18 Pro Max (eSIM): 5,567 mAh → ~15% increase
For comparison, the standard iPhone 18 Pro is rumored to get a modest 1–2% bump: 4,288 mAh (eSIM) / 4,056 mAh (physical SIM) vs. the 17 Pro’s ~4,200 mAh.
The Pro Max is clearly getting the lion’s share of the battery gains this generation.
Why the Split Between eSIM and Physical SIM?
The physical SIM tray takes up internal volume. Removing it (eSIM-only) frees space for a larger battery—hence the ~176 mAh gap between variants. The US has been eSIM-only since iPhone 14; most other markets still get physical SIM trays.
Launch Timeline
The iPhone 18 Pro Max launches next month alongside the iPhone 18 Pro and a new “iPhone Ultra” model. If the leak holds, the Pro Max’s battery life could be a genuine standout feature—especially combined with whatever efficiency gains the A19 Pro chip brings.
Bottom Line
An 11–15% battery capacity increase year-over-year is significant for Apple, where 3–5% has been the norm. If real-world testing bears this out, the iPhone 18 Pro Max could be the battery life king of 2026 flagships.
