Pre-orders for the iPhone Duo opened on Friday, and a new EU regulatory filing has revealed exactly how much battery Apple's first foldable is packing. According to 9to5Mac, the iPhone Duo carries a combined 4883mAh across two separate cells — a 2962mAh cell and a 1921mAh cell.
That number lands the iPhone Duo near the top of Apple's iPhone battery rankings. It's not the biggest iPhone battery ever, but it sits almost exactly between the iPhone 18 Pro and the iPhone 18 Pro Max, which is a strong position for a first-generation foldable.
iPhone Duo battery vs other iPhones
Only the two most recent Pro Max iPhones beat the Duo on raw capacity. The iPhone 18 Pro Max tops the list at 5567mAh, while the iPhone 18 Pro sits below at 4288mAh. The 4883mAh figure cited comes from eSIM models, which Apple equips with larger battery cells than the physical SIM versions sold in some markets.
Compared with anything other than those two Pro Max devices, the Duo has a physically larger battery. That matters because foldables typically struggle to match the endurance of standard phones — a bigger cell helps offset the extra screen.
- iPhone Duo: 4883mAh (2962mAh + 1921mAh dual-cell)
- iPhone 18 Pro Max: 5567mAh
- iPhone 18 Pro: 4288mAh
- All figures refer to eSIM versions, which use larger cells than physical SIM variants
