Apple has made an unexpected slip-up: it has leaked concrete proof in the iOS 27 code that a foldable iPhone exists and will arrive in September. This is not speculation from usual leakers or analyst theories: it is official technical information from the company itself, found in the beta of the operating system it will launch alongside its next generation of mobile devices.

The code reveals what Apple did not want to confirm

According to hipertextual.com, Macworld experts have discovered revealing messages in the battery settings section of iOS 27. What is significant is not what they say, but how they say it: in plural. The texts refer to "this iPhone's batteries" and "one of the batteries", when until now all models in the range have always had a single energy cell.

This change in language is no coincidence. It is how Apple is preparing its operating system to recognise and manage devices with two separate batteries, a feature exclusive to foldable phones. Most devices of this type on the market—from Samsung Galaxy Z Fold to Xiaomi Mix Fold—use dual-battery architectures: one in each half of the device, connected by a flexible cable that runs through the central hinge.

iPhone Ultra arrives in September

Although Apple has never officially confirmed the existence of a foldable iPhone, the industry has been anticipating for months that the iPhone Ultra model will be the company's flagship launch this year. Rumours pointed to September as the announcement month, coinciding with the launch of the rest of the iPhone 18 range. Now, with the discovery in iOS 27, we have technical validation that this device is real and in advanced development stages.

The code changes are not minor details. Apple is adapting crucial features such as temperature monitoring, non-original battery detection, and load balancing between both cells. This requires significant engineering work that only makes sense if the product is close to commercialisation.

What changes for the user: price and maintenance

The adoption of dual batteries has practical implications that will directly affect the consumer's wallet:

• Higher replacement cost: replacing the iPhone Ultra battery will require disassembling more components than current models, which will increase repair time and therefore its price.
• Greater complexity: the cable connecting both cells and additional sensors make replacement non-trivial, unlike in a standard iPhone.
• Cannot replace just one: iOS 27 will detect if one of the two batteries is not original, preventing you from replacing just part of the component.

As for the price of the complete device, there are no signs that the dual battery will dramatically spike the cost—other manufacturers already absorb this expense—but future repairs will indeed be more expensive.

A leak that defines Apple's strategy

This oversight reveals something important about how software development works at Apple: all future hardware management is prepared months before launch. The fact that iOS 27 code already includes specific references to iPhone Ultra means engineers are in the final stretch of optimising the operating system for this model.

Only weeks remain before Apple unveils its foldable smartphone. When it does, we already know it will bring a completely new battery architecture to the brand and that maintenance will not be as straightforward as we are accustomed to.