Apple has released the fourth developer beta of iOS 27. According to a new report effectively sourced from Macworld, the update contains code strings that reference the company’s rumored foldable phone, widely expected to be called the iPhone Ultra. In the Battery Health section of iOS 27 Beta 4, developers spotted phrases such as "the batteries in this iPhone are performing as expected" and "the health of the batteries in this iPhone has significantly degraded." A further string notes that "one of the batteries" is identified as a non‑genuine Apple part.

Apple has never shipped a device with multiple batteries, but the foldable design suggests a dual‑battery architecture. Similar references appeared in the first iOS 27 developer beta, indicating early preparation for a new form factor. The findings suggest Apple is preparing software support for the upcoming iPhone Ultra, though no official announcement has yet been made.

Developers and tech enthusiasts are closely monitoring the beta for additional clues about features, battery management, and software optimisations that will accompany the foldable device. The presence of these strings in a publicly available beta is a clear sign Apple is actively testing the platform for the next-generation iPhone.

These revelations underscore the importance of beta testing in identifying hardware‑specific code, and they hint at a future where Apple’s software will seamlessly manage a multi‑battery, foldable smartphone.