The iPhone Duo has what Apple is calling an "iPhone-first dual battery system" with one battery on each side of the device. Apple optimized physical space for battery capacity to make sure that the battery lasts as long as possible.
When using the larger 7.6-inch inner display (unfolded), the battery lasts for up to 31 hours of video playback.
If you're using just the 5.4-inch outer display, the battery lasts for up to 44 hours when watching video.
With Apple's typical use metric, which includes equal use of both screens, the battery lasts for up to 24 hours. Typical use includes a mix of messaging, photo capture, listening to music, social app use, streaming video, playing games, web browsing, and navigation. Apple says it is based on median usage across iPhone users.
The typical use metric for the iPhone Duo matches the iPhone 18 Pro's. The larger 7.6-inch display draws more power and eats more battery than the 18 Pro when watching video, while the smaller display gets better battery life. The iPhone 18 Pro Max has the longest battery life of the three iPhones at up to 45 hours.
The iPhone Duo is able to charge to 50 percent in around 20 minutes with a 60W or higher USB-C power adapter. It includes support for MagSafe and can wirelessly charge at up to 25W using MagSafe or Qi2.
The two batteries in the iPhone Duo are managed as a single battery by iOS. Apple says battery life was maximized through the two-battery design, eSIM-only design, C2 modem efficiency, and the new A20 Pro chip.
Preorders for the iPhone Duo will start on October 16, with a launch to follow on October 23.
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