iPhone Duo battery capacity sits between Pro and Pro Max
Apple’s first foldable iPhone reportedly packs 4,883mAh across two cells, placing it below the latest Pro Max but above most of the range.
Apple’s iPhone Duo has a combined battery capacity of 4,883mAh, according to an EU regulatory document reported by MacRumors. 2 The figure comes from two cells: one rated at 2,962mAh and another at 1,921mAh. 3
That places the foldable iPhone between the iPhone 18 Pro and iPhone 18 Pro Max by physical capacity. The iPhone 18 Pro is listed at 4,288mAh, while the iPhone 18 Pro Max reaches 5,567mAh. The Duo therefore has more capacity than the standard Pro, but less than Apple’s largest current phone. 3
What the number means
The capacity comparison does not translate directly into battery life, particularly because the Duo has two displays and a larger inner screen. Apple’s product page says the phone can deliver up to 31 hours of video playback when using that inner display. 1 The company also describes the device as using an iPhone-first dual-battery architecture and an eSIM-only design that leaves more physical room for battery capacity. 1
The comparison reported by 9to5Mac places the iPhone Duo above most recent iPhones by capacity, with only the two latest Pro Max models listed higher. The iPhone Duo’s two-cell design is part of the engineering trade-off required by a foldable chassis: it needs to distribute power across a device that can open into a much larger screen. 3
Apple’s official product page positions iPhone Duo as its first foldable iPhone, with a 7.6-inch inner display, an A20 Pro chip and a claimed 31 hours of inner-display video playback. 1 The phone is due to become available on 23 October, following its pre-order period. 1
Our opinion
The 4,883mAh figure makes the Duo look strong on paper, but the more useful comparison is the gap between capacity and screen demand. Sitting between the Pro and Pro Max suggests a substantial battery, while the 31-hour inner-display figure shows why foldables still need their own battery-life context rather than a simple capacity leaderboard. This story is distinct from existing iPhone Duo coverage because it focuses on the newly revealed regulatory capacity and what the dual-cell design means for comparisons across Apple’s range.