Apple has put a number on the iPhone Duo battery. The foldable is rated at 4,883 mAh, which places it between the iPhone 18 Pro and the iPhone 18 Pro Max.
The figure comes from the EU energy label Apple published for the iPhone Duo. Apple rarely lists battery capacity in mAh in its own specs, so the label is where the number surfaces, along with endurance, drop test and repairability ratings.
The iPhone Duo Battery Is About 14 Percent Larger Than the iPhone 18 Pro
The iPhone Duo has no physical SIM tray and activates only with an eSIM, so the 4,883 mAh rating applies to every unit Apple sells, including those in the US. That makes the eSIM-only iPhone 18 Pro and iPhone 18 Pro Max the cleanest comparison.
A teardown of both phones measured the iPhone 18 Pro at 4,288 mAh and the iPhone 18 Pro Max at 5,567 mAh. That puts the iPhone Duo about 14 percent above the smaller phone and about 12 percent below the larger one.
Capacity alone does not decide runtime on a foldable, because the large inner display pulls more power than the outer one. Apple’s battery life numbers for the iPhone Duo are up to 44 hours of video playback on the outer display and up to 31 hours on the inner display. The iPhone 18 Pro is rated at 36 hours and the iPhone 18 Pro Max at 45 hours.
The capacity is split across two cells, one in each half of the foldable, and the phone measures just 5.2mm thick when open.
Apple Rates the iPhone Duo Battery for at Least 1,000 Charge Cycles
The 1,000 cycle rating applies on default settings, and the iPhone Duo earns an A for energy efficiency. The EU rates its endurance at 51 hours 30 minutes per charge. That figure comes from a standardized EU test, so it will not match Apple’s video playback ratings.
The foldable carries an IP68 rating, tested to a depth of 6 meters. Apple’s other durability and support ratings for it include:
- Drop test: at least 140 falls without defect, rated class B
- Drop test, fully extended: 35 falls without defect
- Screen scratch resistance: 5 on the Mohs scale
- Software updates: at least 5 years of security, corrective and functionality updates
The iPhone Duo Battery Is Not User Replaceable and Scores a C for Repairability
Under EU criteria, the iPhone Duo battery is not user replaceable. The foldable scores a C for repairability, with an index of 2.65 out of 5.
Spare parts availability and repair information each score a full 5 out of 5. Fasteners score 2.24, tools score 1.12 and software update duration scores 1.00, which pulls the total down.
Apple’s own battery service costs $229 without AppleCare+. With AppleCare+, the replacement is free once capacity falls below 80 percent.
The iPhone Duo starts at $1,999 for 256GB and goes on sale October 23.
