iPhone Duo pre-orders opened this morning, and the spec Apple keeps pointing to is battery life. Its first foldable is rated for up to 44 hours of video playback on the outer screen and 31 hours on the big inner one, which Apple says beats the iPhone 17 Pro Max. For a phone that is 5.2mm thin when open, that is a bold claim.
Nobody outside Apple has a Duo to test yet. But we do have the next best thing: detailed, independent battery tests of six flagship Android foldables, published by TechRadar’s Nirave Gondhia after weeks of runs on his own CellMark test suite. Those numbers show two things very clearly. Foldable battery life varies wildly between brands, and the figures phone makers print on the box are almost always optimistic.
We took that data, compared every result with the manufacturer’s own claim and used the pattern to estimate what the Duo will really deliver. Here is what we found.
The six foldables in the test
The test group covers the big passport-style foldables you can buy right now, including two that are not officially sold in the US. Battery sizes range from 4,800mAh to 6,660mAh, a 39% spread.
| Phone | Battery | Chip | Sold in the US? |
|---|---|---|---|
| Samsung Galaxy Z Fold 8 | 4,800mAh | Snapdragon 8 Elite Gen 5 for Galaxy | Yes |
| Samsung Galaxy Z Fold 8 Ultra | 5,000mAh | Snapdragon 8 Elite Gen 5 for Galaxy | Yes |
| Google Pixel 11 Pro Fold | 4,806mAh | Tensor G6 | Yes |
| Motorola Razr Fold | 6,000mAh | Snapdragon 8 Gen 5 | Yes |
| Oppo Find N6 | 6,000mAh | Snapdragon, one fewer performance core | No |
| Honor Magic V6 | 6,660mAh | Snapdragon flagship | No |
| Apple iPhone Duo | Dual cells, capacity not disclosed | A20 Pro | Yes, from October 23 |
The Android giants with the biggest batteries, Honor and Oppo, use silicon carbon cells that pack more energy into the same space. That technology is why Chinese foldables keep pulling ahead on capacity, as we explained when Honor showed off a silicon carbon battery as thin as a playing card. Samsung and Google are still a generation behind on that front.
Test 1: web browsing
The browsing test loads 20 of the heaviest pages on the web, scrolls through them and loops until the battery is empty. It is a good stand in for the way most of us use a foldable’s big screen: reading, shopping and scrolling.
The surprise here is Samsung. The regular Galaxy Z Fold 8 had the lowest drain rate of the whole group, about 271mAh per hour, thanks to its smaller screen. It only finished fourth because it has the smallest battery. Give it Honor’s 6,660mAh cell at the same drain rate and it would have run for almost a full day.
The Pixel 11 Pro Fold finished last, and the Razr Fold won by more than an hour. Motorola’s choice of the standard Snapdragon 8 Gen 5 instead of the faster Elite chip pays off in exactly this kind of everyday use.
Test 2: video playback vs what the box says
Video playback is the one test where every manufacturer publishes a number, so it is the best way to check how honest those numbers are. The test looped a locally stored 4K video at 50% brightness.
| Phone | Maker’s claim | Measured | Share of claim delivered |
|---|---|---|---|
| Honor Magic V6 | 24 hours | 21h 57m | 91% |
| Oppo Find N6 | 26 hours | 22h 47m | 88% |
| Galaxy Z Fold 8 | 26 hours | 20h 32m | 79% |
| Galaxy Z Fold 8 Ultra | 27 hours | 20h 39m | 76% |
| Pixel 11 Pro Fold | 24 hours | 18h 14m | 76% |
| Motorola Razr Fold | 39 hours | 20h 49m | 53% |
Measured times from TechRadar’s CellMark video test. Percentages are our calculation: measured time divided by the manufacturer’s claim.
Not one phone reached its rated figure. Honor and Oppo came close, delivering about 90% of what they promised. Samsung and Google landed around three quarters. Motorola’s 39-hour claim was the outlier, and the Razr Fold managed barely half of it, despite being one of the best performers in absolute terms.
Part of the gap is methodology. Manufacturers test in ideal lab conditions, often with lower brightness, airplane mode and fresh batteries. Still, the pattern is useful: across these six phones, the median foldable delivered about 78% of its claim.
Test 3: heavy loads and heat
Browsing and video are the scenarios phone makers optimize for. The harder test is sustained heavy work. The “Synthesizer” test hammers the processor with prime number calculations and background file operations until the phone dies, which is a decent proxy for long gaming sessions or video editing.
| Phone | Projected life under heavy load | Drain per hour |
|---|---|---|
| Honor Magic V6 | 12h 37m | 7.5% |
| Oppo Find N6 | 11h 32m | 8.2% |
| Motorola Razr Fold | 10h 55m | 8.6% |
| Pixel 11 Pro Fold | 7h 05m | 13.3% |
| Galaxy Z Fold 8 Ultra | 6h 03m | 15.5% |
| Galaxy Z Fold 8 | 5h 51m | 16.1% |
This is where the philosophies split. Samsung does not throttle the Snapdragon 8 Elite Gen 5 in its Folds, so they finish more work per minute but run out in under six hours. Honor, Oppo and Motorola trade a little peak speed for roughly twice the endurance. Oppo uses a chip with one fewer performance core, and Motorola skipped the Elite chip entirely. Both choices were made with battery life in mind, and it shows.
The social media “doom scroll” test told a similar story about heat. The Galaxy Z Fold 8 Ultra, Samsung’s thinnest Fold, spent 27.5% of its run at a “critical” thermal level, the only phone in the group to get anywhere near it. Hot phones drain faster, so thin designs pay twice.
Charging speed
The cleanest way to compare charging across different battery sizes is how much energy each phone takes in per minute on average.
Samsung’s 45W charging got the Galaxy Z Fold 8 to about 66% in 30 minutes, and the Ultra to 71%, because it sustains peak speed for longer. Apple says the iPhone Duo reaches 50% in about 20 minutes with a 60W-capable adapter, or in 30 minutes on a 35W MagSafe charger. That would put it roughly level with the Fold 8 Ultra and the Honor Magic V6, though Apple has not published a full charge time.
What this means for the iPhone Duo
Here is the official Apple rating, straight from the spec sheet, and what it could look like in practice.
Apple rates the Duo at up to 44 hours of local video on the outer screen and 31 hours on the inner screen, with 37 and 26 hours for streamed video and up to 24 hours of “typical use.” If the Duo hits the same 78% median as these Android foldables, you would get around 34 hours folded and 24 hours unfolded. That is still longer than any foldable in the test, including the Oppo Find N6 at 22h 47m.
There are reasons to think Apple may do better than the median. Its video ratings have historically held up well in independent testing, and TechRadar found the iPhone 18 Pro’s 36-hour claim accurate in its own review. The Duo is also thicker than the slimmest Android rivals at 11.3mm folded, uses a vapor chamber and splits its capacity across two battery cells, one in each half. That should help it stay out of the thermal trouble that hurt the Fold 8 Ultra. We covered the rest of the hardware, including its 100-part hinge, in our iPhone Duo specs breakdown.
The real unknown is the A20 Pro under load. It is a very fast chip, and Apple tunes for performance much like Samsung does. If the Duo behaves like the Galaxy Folds in sustained work, heavy gamers could see six to eight hours of screen time rather than the 11 to 12 hours Honor and Oppo deliver.
Which foldable has the best battery life?
| Category | Winner | Runner-up |
|---|---|---|
| Web browsing | Motorola Razr Fold (20h 14m) | Oppo Find N6 (18h 52m) |
| Video playback | Oppo Find N6 (22h 47m) | Honor Magic V6 (21h 57m) |
| Heavy loads | Honor Magic V6 (12h 37m) | Oppo Find N6 (11h 32m) |
| Charging speed | Oppo Find N6 | Honor Magic V6 |
| Most honest claim | Honor Magic V6 (91%) | Oppo Find N6 (88%) |
| Best sold in the US | Motorola Razr Fold | Galaxy Z Fold 8 |
Samsung’s Folds are the safe mainstream choice and the most widely supported in the US, which we covered at launch in our Galaxy Z Fold 8 and Z Fold 8 Ultra announcement coverage. On battery, though, the test makes it clear that a bigger, newer foldable is not automatically a longer lasting one. The Ultra’s larger cell could not save it from its thin, hot body.
FAQ
Which foldable phone has the best battery life in 2026?
In independent tests, the Honor Magic V6 and Oppo Find N6 performed best overall, and the Motorola Razr Fold led web browsing at 20 hours 14 minutes. Among foldables sold in the US, the Razr Fold is the strongest performer.
How long does the iPhone Duo battery last?
Apple rates it for up to 44 hours of video playback on the outer display, 31 hours on the inner display and up to 24 hours of typical use. Independent results are not available yet.
How fast does the iPhone Duo charge?
Up to 50% in about 20 minutes with a 60W-capable USB-C adapter, or in about 30 minutes with a 35W adapter on a MagSafe charger. Both are sold separately.
Are foldable phone battery claims accurate?
Usually not fully. In the tests covered here, real video playback ranged from 53% to 91% of the manufacturer’s claim, with a median of about 78%.
Does the Galaxy Z Fold 8 have good battery life?
It is efficient for everyday browsing, lasting 17 hours 44 minutes, but drains fast under heavy loads at under six hours. Lowering brightness and turning off background sync stretched one test run to more than 24 hours.
About this article: GeekBlog covers U.S. technology news, AI, phones, smartwatches and gaming. Every story is written and checked under our Editorial Policy. Spotted a mistake or have a story tip? Contact our editors.
