Apple just released the fourth beta of iOS 27 for developers, and something interesting has already been found in it. Right in the system’s code, strings were discovered that hint at an iPhone with multiple batteries inside. Nothing like this has ever appeared in any iPhone throughout its entire history, so the discovery instantly spread across tech publications. Let’s figure out what device this is about and why a smartphone would need two batteries instead of the usual one.
The foldable iPhone will have multiple batteries
What Was Found in the iOS 27 Beta 4 Code
Macworld dug through the fresh build and stumbled upon a couple of curious strings. The system usually stores service texts about battery status — the same phrases you see in the battery health section. In the new beta, similar messages appeared, but already in plural form, which immediately catches the eye.
One of the strings reports that the batteries in this iPhone are working as expected. Another warns that battery health has significantly degraded. The key difference here is the word in plural form instead of the usual singular. The old strings about a single battery haven’t gone anywhere — they remain in place for regular models.
Each half will have its own battery
So it turns out Apple has divided iPhones into two groups right in the code: those with one battery and those with multiple. This is no longer guesswork — it’s a very specific trace in the system that’s hard to dismiss as coincidence.
Two Batteries in iPhone Ultra: Why They’re Needed
Earlier this month, insider Digital Chat Station from Weibo revealed that the upcoming iPhone Ultra will get not one, but two separate batteries. At the time, it sounded like yet another rumor, of which plenty have accumulated around the top-tier model. Now the story has gained solid confirmation, straight from the depths of the operating system.
For foldable smartphones, a pair of batteries is standard practice. When the body folds in half, it’s much easier for engineers to place two separate cells in different halves than to squeeze one large battery into a thin, bending body. But for the iPhone, this will be the first such case in the entire history of the lineup, which is quite noteworthy in itself.
Previously, references to a foldable iPhone and a version with multiple displays had already been found in iOS 27 code. They’re clearly preparing a serious flagship, and it definitely won’t be limited to just the batteries.
iPhone Ultra Battery Capacity: What We Know
The most interesting part of this whole story is the specific numbers. According to data from a regulatory filing, the iPhone Ultra will have two batteries with capacities of 1,921 mAh and 2,962 mAh. Combined, this gives a solid 4,883 mAh, which is noticeably more than today’s top iPhones.
The iPhone Ultra battery capacity leaked online earlier, and it won’t be record-breaking
For comparison, current flagships usually have a capacity of around just over three thousand mAh. So the increase is truly substantial, and the logic is simple: a foldable body with two screens consumes energy much more actively than its flat counterpart. Two batteries in such a device are not a luxury or marketing gimmick, but a basic necessity.
This setup also has a pleasant side effect. The system can charge and discharge two separate cells alternately, which directly affects battery longevity. Simply put, each battery wears out more slowly than a single module that carries the entire load on its own. For a device that will likely cost as much as half a used car, this is a significant advantage.
However, I’d advise keeping in mind that this is all still at the level of leaks and code discoveries. Apple will only confirm the final specifications at the official presentation, and we still have to wait for that.
When Will iPhone Ultra Be Released
The wait for the iPhone Ultra release won’t be long
If analyst predictions are to be believed, Apple will unveil the iPhone Ultra in early September along with the entire new smartphone lineup. There’s very little time left until the announcement, which means there will only be more leaks and code discoveries. Each new iOS 27 beta reliably delivers fresh details, so there’s definitely no chance of getting bored. While some strings confirm each other, others sometimes contradict, so we’ll only piece together the complete picture closer to fall. It’s precisely on such discoveries that half of all major leaks around new iPhones are built.
Personally, I really like the idea of two batteries — if the foldable iPhone can last longer than a couple of hours, that’s already a serious argument in its favor. We’ll see how it turns out in practice, because many things look great on paper but often feel quite different in hand.
