Apple may have dropped one of its biggest hints yet about its long-rumoured foldable iPhone. References found in the fourth developer beta of iOS 27, which is now available to download, point to an iPhone with two internal batteries, a change from the single-battery wording used on current iPhone models. The discovery, first reported by Macworld, has almost confirmed that the software is preparing for Apple’s first foldable iPhone, widely rumoured to debut later this year.
iOS 27 beta 4 contains iPhone Ultra battery reference
Macworld found new Battery Health strings in the latest iOS 27 developer beta that refer to “the batteries in this iPhone” instead of “the battery in this iPhone.” Other messages also mention that “one of the batteries” may not be verified as a genuine Apple battery, suggesting the operating system is capable of monitoring multiple battery cells independently.
Current iPhone models only contain a single battery, and the wording throughout the Battery Health section reflects that. The shift to plural references therefore stands out, although Apple hasn’t confirmed what device these strings are intended for. It’s most likely the foldable iPhone Ultra.
- “The batteries in this iPhone are performing as expected.”
- “The health of the batteries in this iPhone has significantly degraded. An Apple Authorized Service Provider can replace the batteries to restore full performance and capacity.”
- “The health of the batteries in this iPhone has significantly degraded, and one of the batteries could not be verified as a genuine Apple battery. An Apple Authorized Service Provider can replace the batteries to restore full performance and capacity.”
Earlier reports claimed Apple’s foldable iPhone would use two battery cells with capacities of 1,921mAh and 2,962mAh, combining for a total capacity of 4,883mAh. That design would be similar to most existing foldable smartphones, which typically split the battery between the two halves of the device to make better use of internal space.
This also isn’t the first time Apple’s iOS is pointing towards a foldable iPhone. The iOS 27 first beta had references to angle detection and fold states, implicitly confirming that they’re referring to the iPhone Ultra.
The new iOS 27 strings also suggest each battery could potentially be serviced separately. If that is true, replacing only the degraded battery instead of the entire battery assembly could help reduce repair costs for some users. While Apple has yet to announce a foldable iPhone, software references often appear months before new hardware reaches consumers, though they should not be treated as confirmation of an unreleased product. Apple is expected to unveil its first foldable iPhone alongside the iPhone 18 Pro series in September.
The latest discovery is another indication that Apple is preparing software support for a new form factor rather than a guarantee of specific hardware. Foldable phones from Samsung, Google, Honor and other brands already use dual-cell battery designs, so Apple’s implementation would follow an established approach. Those planning to upgrade this year may want to wait until Apple’s September event if they are interested in a foldable iPhone.
