iOS 27 beta code reveals Apple’s dual-battery iPhone plans

Macworld

Apple has just released the fourth developer beta of iOS 27, and buried deep inside the update is what may be one of the clearest references yet to the company’s long-rumored foldable iPhone.

Macworld discovered new Battery Health strings referencing an iPhone with multiple internal batteries, a setup no current iPhone has, but one that would make a lot of sense for a foldable device.

iOS 27 lays the groundwork for Apple’s foldable iPhone

The new code strings explicitly state that they are intended for a multi-battery iPhone, alongside the existing references to single-battery iPhones (emphasis ours): “The batteries in this iPhone are performing as expected,” reads one of the strings. Another mentions that “the health of the batteries in this iPhone has significantly degraded.”

The wording is notable. Rather than referring to a single battery, as every current iPhone does. Apple now explicitly talks about “the batteries in this iPhone” and even mentions a situation where “one of the batteries” may not be a genuine Apple part.

The folding iPhone Ultra is expected to utilize a dual-battery system, with separate batteries on both sides of the display.

Foundry

On its own, that might not sound like much. After all, it’s not likely that Apple is going to suddenly shove two batteries into an iPhone Pro Max. But given the rumors that Apple’s expected to reveal its first foldable iPhone this fall (the so-called iPhone Ultra ), the idea of adding dual-battery support suddenly makes a whole lot of sense.

Once again, no shipping iPhone today would ever trigger these strings. Every current model contains a single battery, making the new “multi-battery” wording difficult to explain unless Apple is actively developing hardware with a different internal architecture. Back when the iPhone X arrived, Apple implemented a twin-cell L-shaped battery design for space purposes, but they functioned as a single battery. The wording here makes it seem as though the batteri…