The foldable iPhone continues to gain new details, and this time it’s about the battery. According to well-known Chinese insider Digital Chat Station, Apple will use two battery cells in the foldable iPhone Ultra. In principle, this is logical, considering that the smartphone itself will consist of two parts. What’s interesting here is something else — the total battery capacity will be 4883 mAh, which is noticeably less than the top-tier iPhone 18 Pro Max, which will also become noticeably thicker. Let’s break down what this means for battery life and how much it will differ across various iPhone models.
The battery in iPhone Ultra won’t be very large
Foldable iPhone Battery Capacity: What We Know
Let’s note right away: this is a leak, not official Apple data, so these figures should be taken with caution. Although overall, the story doesn’t look like a fabrication. Apple’s main supplier registered two battery cells with nominal capacities of 1921 mAh and 2962 mAh for each part of the foldable iPhone Ultra respectively.
Together, this gives a minimum total capacity of about 4883 mAh. The insider himself adds that the supply chain is targeting a range of 4800–5000 mAh, but there’s no final confirmation yet. That is, it’s possible we’re still talking about a test prototype. However, the final version is unlikely to differ significantly upward.
Two separate cells are no coincidence either. That’s how most book-style foldable smartphones are designed: the battery is split into two halves to fit into both parts of the body. Based on the leak, Apple is going the same route.
Foldable iPhone vs. iPhone 18 Pro Max
The main question is whether this is a lot or a little. Apple hasn’t published official specifications, but we can rely on leaks, of which there have been plenty by now.
Let’s compare the batteries of all three Apple novelties coming out this year. The hours of battery life in the last column are our own calculation, not an Apple promise: we’ll explain how we got it below.
| Model | Battery Capacity | Screen | mAh per inch | Video, hours (estimate) |
|---|---|---|---|---|
| iPhone 18 Pro | ~4288 mAh | 6.3″ | ~681 | ~33 |
| iPhone 18 Pro Max | ~5567 mAh | 6.9″ | ~807 | ~42 |
| Foldable iPhone Ultra | ~4883 mAh | 7.8″ + 5.5″ | ~626 | ~30–35 |
The last column is the most interesting. Per inch of inner screen, the foldable iPhone has the least energy of the three: approximately 626 mAh versus 807 for the iPhone 18 Pro Max. The difference is almost 25%. The Ultra’s battery is larger than the iPhone 18 Pro’s, but it also has to feed a much more power-hungry display.
Let’s be honest: compared to many competitors, the foldable iPhone looks decent, but without any records. The Pixel 10 Pro Fold got 5015 mAh, while the Samsung Galaxy Z Fold 7 got 4400 mAh. So Apple beats Samsung and nearly catches up with Google, staying in the middle of the segment.
The iPhone Ultra clearly won’t be the battery life king
Foldable iPhone Battery Life: What to Expect
Hours of battery life for the iPhone Ultra haven’t been named even by insiders yet. But we have a reliable reference point: the current iPhone 17 Pro Max with a 5088 mAh battery is rated by Apple at 39 hours of video, and the iPhone 17 Pro at 33 hours. Dividing one by the other gives approximately 7.7 hours of video per thousand mAh.
The chips and screens in the 18th lineup are changing evolutionarily, so the ratio can be applied to the new models. For the iPhone 18 Pro, it comes out to about 33 hours — exactly the same as the current 17 Pro, with almost no improvement. For the iPhone 18 Pro Max, it comes to 42–43 hours, which is already a noticeable step forward.
But with the foldable, everything is more complicated. By pure capacity, it should deliver about 37 hours, but the 7.8-inch inner screen consumes noticeably more than the 6.9-inch one. Adjusting for this, the realistic range for the iPhone Ultra is 30–35 hours of video. This creates a paradox: the foldable’s battery is larger than the iPhone 18 Pro’s, but it will last the same amount of time or even less.
There are also positive factors. Back in March 2025, a rumor appeared that Apple is focusing on energy efficiency while simultaneously trying to reduce the thickness of key components in the foldable iPhone. Taiwanese analyst Ming-Chi Kuo separately noted that the device will feature a battery with increased density — meaning more capacity in the same volume. Plus, foldable smartphones aren’t always used in the open position: some of the time only the external 5.5-inch screen is active, and it’s much more economical.
The inner screen of iPhone Ultra will clearly consume considerable resources
There’s also a contradiction. An earlier leak mentioned testing of a much larger battery — from 5400 to 5800 mAh. But that referred to an engineering sample, not the final device. Either Apple revised the design, or that rumor was inaccurate — this can’t be determined from publicly available data.
Foldable iPhone Ultra: Specs and Price
Based on the sum of rumors, the foldable iPhone may launch under the name iPhone Ultra. Here’s what is known about it at the level of leaks and predictions:
- inner screen about 7.8 inches and outer screen about 5.5 inches;
- Touch ID instead of Face ID;
- A20 chip and Apple C2 modem in some countries;
- announcement alongside iPhone 18 Pro in September.
Now about the money. IDC analysts forecast an average price of about $2,500 — that’s approximately 269,000 ₽ at the current exchange rate. Versions with larger storage could reach $3,000, or roughly 323,000 ₽. Even by the standards of top-tier iPhones, this is very expensive.
Should You Wait for the Foldable iPhone Ultra
For now, we’re talking about a leak, not a finished product, so there’s nothing to buy — you can only observe. According to supply chain data, the first foldable iPhone remains on schedule and is expected in September alongside the iPhone 18 Pro.
If you’re looking at a regular iPhone and maximum battery life is important to you, the foldable device is unlikely to be your choice: by our estimates, it will lose even to the iPhone 18 Pro, while costing three times as much. It’s worth following for those who need a large inner screen in their pocket and who are willing to pay for the form factor. Everyone else can calmly wait for the September presentation and not treat the leaked figures as final.
