The iPhone Duo has a 4,883 mAh battery in total, according to the EU energy label Apple has filed for the foldable (model A3720). The label rates that battery for at least 1,000 charge cycles under default settings. It also lists the battery as not user-replaceable.
The total matches the figure earlier leaks pointed to. MacRumors reports that Apple published the label on Friday, though the document itself carries no date. For the rest of the hardware, see our iPhone Duo price and specs rundown.
What the iPhone Duo battery label lists
Apple’s product information sheet for the iPhone Duo includes these battery and durability entries:
- Rated battery capacity: 4,883 mAh
- Battery endurance: at least 1,000 charge cycles, default settings
- EU endurance per cycle: 51 hours 30 minutes
- User-replaceable battery: no
- Energy efficiency class: A
- Dust and water: IP68, up to 6 metres for 30 minutes
- Repairability: class C, index 2.65 out of 5
- Software updates: at least five years, counted from when Apple stops placing it on the market
- Guarantee: 12 months
Two batteries, one total
Apple’s UK specification page says the Duo uses two built-in lithium-ion batteries. The EU label gives only the combined capacity. An earlier leak, as MacRumors describes it, split that total into 2,962 mAh and 1,921 mAh cells. Apple has not confirmed the split.
MacRumors, citing iFixit figures, puts the eSIM-only iPhone 18 Pro at 4,288 mAh and the iPhone 18 Pro Max at 5,567 mAh. That places the Duo between the two on paper. Capacity is not battery life, though, and the Duo has two displays to power.
Apple’s own battery life claims
Apple rates the Duo for up to 24 hours of typical use. It claims up to 44 hours of video playback on the outer display and up to 31 hours on the inner one. Streamed video is rated at up to 37 and 26 hours respectively.
These are Apple’s figures, measured on pre-production units in July and August 2026, according to its footnotes. The EU’s 51.5-hour cycle figure comes from a different test, so the two sets of numbers don’t line up directly.
For charging, Apple says the Duo reaches 50% in around 20 minutes with an adapter of 60W or more.
Repairs and the eSIM tradeoff
The label answers the user-replaceable question with a plain no. It does point to Apple’s Self Service Repair programme for parts and manuals. Apple’s battery service costs $229 without AppleCare+, as we reported earlier this month.
Apple’s UK page also confirms the Duo is eSIM-only and won’t take a physical SIM card. Apple pitches that as more convenient and more secure. The cost to buyers is that you can’t move a SIM card between phones, and every carrier you use must support eSIM.
MacRumors infers that the 4,883 mAh figure applies worldwide, because no SIM-tray version exists. Apple’s page backs the no-SIM-tray part, but not the worldwide claim itself.
Sources: Apple EU energy label, Apple UK specifications, MacRumors
