Apple’s first foldable smartphone, the iPhone Duo, has been confirmed to have a battery capacity of 4,883 mAh. It is the third largest among recently released iPhones, larger than the standard Pro model but smaller than the Pro Max.

On Oct. 18, local time, tech media outlet 9to5Mac reported that Apple disclosed the total battery capacity by releasing European Union energy-efficiency regulatory documents after starting iPhone Duo preorders.

The iPhone Duo is known to include two battery cells with capacities of 2,962 mAh and 1,921 mAh. The combined total is 4,883 mAh. The batteries are split and arranged to suit the foldable structure.

That is larger than the iPhone 18 Pro’s 4,288 mAh but smaller than the iPhone 18 Pro Max’s 5,567 mAh. Among recently released iPhones, it is the third largest after the iPhone 18 Pro Max and the iPhone 17 Pro Max at 5,088 mAh.

Compared with other models, the iPhone 16 Pro Max has 4,685 mAh, the iPhone 17 Pro has 4,252 mAh, the iPhone 17 has 3,692 mAh, and the iPhone Air has 3,149 mAh. The comparison is based on eSIM-only models, which can secure more battery space, and the iPhone Duo also supports only eSIM, with no physical SIM card slot.

A larger battery capacity does not necessarily mean longer real-world usage time. The iPhone Duo shows a significant difference in battery life when the screen is folded versus unfolded.

According to Apple’s official data, video playback lasts up to 44 hours when using the outer display and up to 31 hours when using the inner display. Using the unfolded screen cuts playback time by up to 13 hours.

The gap also appears for streaming video playback, with up to 37 hours on the outer screen and up to 26 hours on the inner screen.

The iPhone Duo’s battery performance is likely to feel very different depending not only on total capacity but also on how often users switch between the outer and inner screens.