iOS 27 beta 4 reveals an iPhone with two batteries, new hint about the foldable?

Apple seems poised to expand its lineup of mobile devices with a brand-new product, and the clearest traces of this development come directly from its operating system.

The fourth developer beta of iOS 27 has indeed uncovered very explicit references to a smartphone equipped with two batteries.

This discovery, initially traced by Macworld, strongly reinforces the hypothesis of Cupertino’s imminent debut of the much-discussed foldable smartphone, providing clear indications regarding both the internal technical structure and the new maintenance approaches planned.

iPhone Ultra, new confirmations from iOS 27 Beta 4

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By analyzing the code strings of the recent test release, developers identified a series of new warnings placed in the settings section dedicated to the phone’s health status.

Until the current iPhone generation, official wording has always referred to a single power unit. The new texts, by contrast, clearly pluralize the term. In the settings you can now read phrases such as “the batteries in this iPhone are functioning as expected,” or warnings indicating that battery health has significantly degraded.

A particularly telling error message flags the inability to confirm whether “one of the batteries” is an original Apple component, inviting the user to contact an authorized service provider.

A dual battery is easier to replace

The use of separate cells is a widely adopted feature in the foldable smartphone sector. Such devices typically house one cell in each half of the chassis, balancing overall weight and optimizing the distribution of internal space.

Based on the speculation circulating so far, this as-yet-unreleased model, which could be marketed under the name iPhone Ultra, will adopt exactly this philosophy.

Preliminary information indicates the adoption of two units with asymmetric dimensions: one of 1,921 mAh and a second of 2,962 mAh. The combination of the two cells would give the device a total capacity of 4,883 mAh.

The plurality of messages integrated in iOS 27 suggests an additional practical advantage related to support. It is highly likely that the two units of the iPhone Ultra can be diagnosed and replaced completely independently. If one cell wears out or shows defects earlier than the other, technicians could intervene only on that cell.

Such modularity would bring a considerable economic benefit, reducing the replacement costs for end users outside the warranty period.

The wait for field testing of these rumors shouldn’t be long: the expected timing indicates that Apple will unveil its first foldable device in September, alongside the launch of the upcoming iPhone 18 Pro lineup.