The first iPhone Duos will be landing in users' hands by the end of this week, and it means we finally get a chance to find out all the things we still don't know about the phone. One thing we can cross off the list is the phone's total battery capacity, thanks to the newly published EU energy label.
According to EU law, all phones that go on sale in the region also need a publicly accessible Energy Label, which offers key details about the device in question. Alongside information like IP rating, drop test performance and repairability, the labels also lists the phone's energy performance and battery specs. In the case of the iPhone Duo, it confirms the long-standing rumor that the phone packs in a 4,883 mAh battery pack.
For reference the eSIM-only variants of the iPhone 18 Pro and iPhone 18 Pro Max both have respective 4,288 mAh and 5,567 mAh batteries. Which means the iPhone Duo falls somewhere in the middle of the two.
However, considering this is a dual screen phone, one of which is almost 8-inches in size, it's not entirely clear whether the actual battery life will do the same. We'll have to wait and see how the Duo fairs in our own battery life testing.
How iPhone Duo's battery compares to other foldables
Battery Capacity (mAh) | Battery Life (Hrs:Mins) | |
iPhone Duo | 4,883 | N/A |
iPhone 18 Pro | 4,288 | 16:17 |
iPhone 18 Pro Max | 5,567 | 18:27 |
Samsung Galaxy Z Fold 8 | 4,800 | 12:50 |
Samsung Galaxy Z Fold 8 Ultra | 5,000 | 14:33 |
Google Pixel 11 Pro Fold | 4,806 | 12:31 |
Motorola Razr Fold | 6,000 | 14:44 |
As you can see, the iPhone Duo's battery life isn't dissimilar to that of other foldables out there. It's slightly below the Z Fold 8 Ultra, and slightly higher than the Pixel 11 Pro Fold, though both of them are full size book-shaped foldables with a little more space for larger batteries. As is the Motorola Razr Fold, which has a hefty 6,000 mAh battery hiding inside.
The closest we have to Apple's passport-shaped design is the Samsung Galaxy Z Fold 8, which has a slightly smaller 4,800 mAh battery.
This phone lasted just shy of 13 hours during testing, which may give us a benchmark of what to expect from the Duo. Not only is Apple's battery store an extra 83 mAh of power, it also features the same energy-saving features as the 18 Pro series — including the A20 Pro chipset and C2 modem.
I'd expect the iPhone Duo to last a little longer than the Z Fold 8 based on those two factors, but we can't know for sure until we actually get it into the Tom's Guide lab.
Everything else the EU just revealed about iPhone Duo
The EU Energy Label also confirmed some other details. One of which is that the Duo's battery is rated for 1,000 full recharge cycles (zero to 100% and back), which means it should keep at least 80% of its total capacity for that duration.
The Duo also lasted 140 free falls without causing problems, though this number dropped to 35 when it was dropped with the screen fully open.
So as durable as it may be, the iPhone Duo is still a lot more fragile if you leave the inner screen open and exposed. For comparison the Z Fold 8 and Z Fold 8 Ultra both lasted 210 drops, which dropped to 45 when opened, while the iPhone 18 Pro Max lasted 180.
As for water, the phone is IP68 rated (as expected) and is capable of being immersed in up to six meters of water. The screen is also listed as scratch-resistant up to 5 Mohs on the hardness scale, compared to just one on the Z Fold 8 series. Since this is the same as the iPhone 18 Pro Max, which has a Ceramic Shield 2 display, my guess is that only the Duo's outer display was tested.
The Duo's repairability index score of 2.65 is also lower than that of the other three phones. The 18 Pro Max hit 3.14, while the Z Fold 8 and 8 Ultra score 2.79 and 2.78, respectively.