For years, foldable phones haven’t exactly been praised for their battery life. However, that is starting to change.
Because of their unique design, flip phones have traditionally struggled to match the battery life of conventional flip phones. Their massive display, space-consuming hinge mechanisms and limited space for heat dissipation all present challenges. But battery technology has improved in recent years, with some of the newest foldables taking advantage of higher energy-density silicon-carbon batteries and more energy-efficient processors. Even slim phones like the Galaxy Z Fold 8 can last all day, showing that you don’t have to sacrifice practicality for a sleek, innovative design.
Nevertheless, foldable phones remain a niche category, even with a major player like Apple entering the market with the iPhone Duo. But they offer an attractive alternative for anyone who wants to break away from the monotony of more traditional flip phones. And since battery life is a key consideration when choosing a new device, it’s important to know how a phone can keep up with all your scrolling, streaming and snapping without constantly reaching for a charger.
We dug into CNET’s extensive smartphone lab data to find out which foldable phone in 2026 will deliver the best battery life. Because book-style and flip phones differ in design and screen size, we separate the results to provide a more accurate comparison.
Here’s how devices from Samsung, Apple, Google and Motorola stack up.
Which foldable book style has the best battery life?
This year, CNET reviewed and tested five book-style foldable phones: the Samsung Galaxy Z Fold 8, Z Fold 8 Ultra, Motorola Razr Fold, Google Pixel 11 Pro Fold and the Apple iPhone Duo. These devices are phone-tablet hybrids, with designs ranging from taller, narrower builds to squatter, passport-style designs. (We didn’t include the Samsung Galaxy Z TriFold because of its unique design.)
Apple’s $1,999 iPhone Duo may be late to the foldable game, arriving seven years after Samsung’s first Galaxy Fold ushered in the modern era of foldable phones. Still, with Apple’s strong brand loyalty and mainstream appeal, the duo has generated significant buzz.
And there’s another reason Apple’s first foldable deserves attention: its battery. The iPhone Duo achieved the highest average score in CNET’s test among book-style phones. It’s a testament to its dual-cell battery design, which is standard and foldable, and the efficiency of the A20 Pro chip that powers the device.
To test a phone’s battery, CNET runs a 3-hour streaming video test and a 45-minute endurance test that includes watching videos, scrolling through social media, playing a game, and participating in a video call. Both tests take place on the inner screen of the foldable phone, starting with a full charge and while connected to Wi-Fi.
The iPhone Duo had the highest remaining charge after the 45-minute endurance test, finishing at 99%. It completed the 3-hour streaming test with 84%, placing it just below the Razr Fold, Galaxy Z Fold 8 and Z Fold 8 Ultra in this category. This average gives the Duo, which has a 4,883-mAh battery, the number one spot in our foldable battery testers.
Not far behind is the Razr Fold, Motorola’s first foldable book style. This phone has a whopping 6,000-mAh silicon-carbon battery, which helped it earn one of the top spots in our battery tester.
Samsung’s Galaxy Z Fold 8, which is the company’s first palm-sized foldable phone, is barely the more standard-sized Z Fold 8 Ultra. Both phones are the thinnest in this ranking, which makes their results even more impressive. The Galaxy Z Fold 8 measures 4.5 mm thick when unfolded and 9.7 mm when folded, and has a 4,800 mAh silicon-carbon battery. The Z Fold 8 Ultra is 4.1 mm thick when open and 8.9 mm when closed, and it has a 5,000 mAh silicon-carbon battery.
Close behind the competition is the Google Pixel 11 Pro Fold, which has a 4,806 mAh battery. Like the other phones, including the iPhone Duo, it did relatively better in the endurance test than in the streaming test. That suggests these devices can handle shorter bursts of use well, but can take a more noticeable battery hit during longer activities like video streaming. Still, they should easily get through a full day of mixed use, whether you’re watching movies, scrolling through social media, or taking photos.
Overall, every book style foldable we tested demonstrated strong battery results. Beyond the numbers, our hands-on experience suggests that you can get through most days without constantly worrying about your phone’s battery level. Be sure to check out CNET’s in-depth reviews for more on the day-to-day experience with each of these phones.
Which foldable clamshell has the best battery life?
Some people may prefer the more nostalgic design of a flip phone. Motorola has revived its iconic Razr brand for the smartphone era, and now has a handful of devices at varying price points to choose from. Samsung’s Galaxy Z Flip 8 is another pocket-friendly choice.
These clamshell devices have less space for a battery than larger flip and slab phones. Still, Motorola and Samsung’s battery specs are nothing to sneeze at.
This year’s $800 Motorola Razr has a 4,800 mAh battery, the $1,100 Razr Plus has a 4,500 mAh battery and the $1,500 Razr Ultra has a 5,000 mAh battery. Meanwhile, the $1,200 Z Flip 8 has a 4,300 mAh battery. Each of these phones uses a silicon-carbon battery to squeeze more power into a smaller design.
Impressively, the baseline Motorola Razr has the best average score in our battery tests of clamshell phones. It also had the highest score in CNET’s 3-hour streaming test among its peers and tied with the much more expensive Razr Ultra in our battery endurance test. The Razr Ultra, Galaxy Z Flip 8 and Razr Plus are in a row.
Interestingly, flip phones aren’t that far behind their book-style counterparts in our test. One key advantage is that their smaller cover and inner displays require less power, which helps them keep up with larger foldables.
The results are also proof of how battery technology is progressing, with the mobile industry moving more and more towards high-density silicon-carbon batteries that pack more capacity and tighter dimensions. This means that whether you choose a book-style or clamshell foldable, you can be sure that your battery won’t let you down during your day.
Final thoughts: How good is battery life on foldable phones?
From the latest foldables like the iPhone Duo and Pixel 11 Pro Fold to flip phones from Motorola and Samsung, you no longer have to sacrifice battery life for a more versatile mobile design. Today’s devices can comfortably get you through a full day of swiping, scrolling and snapping photos, even with larger screens.
In fact, when ranked among all the phones that CNET tested this year, including non-folding options, the iPhone Duo is among the top five performers, with the iPhone 18 Pro Max in the highest place.
That’s especially important because a big part of a foldable phone is the ability to switch between two displays. You can quickly send a text on a smaller screen, then move to a larger one to watch a movie, for example. This versatility requires a battery capable of handling more intensive tasks such as streaming and gaming, as well as extended activities such as browsing and working across multiple displays.
And while the iPhone Duo and Motorola Razr topped CNET’s foldable battery tests, the other phones we evaluated weren’t far behind, underscoring how competitive battery life has become in the leading brands. Ultimately, choosing the right foldable will come down to other factors, including camera performance, design and price.
Our test data, combined with real-world experiences shared in our detailed reviews, illustrate how far foldable phones have evolved. They are no longer just a novelty; they have become increasingly practical devices in their own right.
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