Samsung’s decision to keep a 5,000mAh battery in the Galaxy S26 Ultra sounded, at first, like a recipe for disappointment. With several Android rivals pushing bigger silicon-carbon batteries and eye-catching capacity numbers, many shoppers expected Samsung to fall behind in real-world endurance. But a recent battery drain test suggests the opposite: the Galaxy S26 Ultra delivers impressively long battery life, even while sticking to the same battery size seen in previous Ultra models.
In a head-to-head battery drain gauntlet conducted by YouTuber Mrwhosetheboss, the Galaxy S26 Ultra was tested alongside six other top-tier flagships, including Apple’s iPhone 17 Pro Max. There was initial skepticism that Samsung’s newest flagship wouldn’t keep up, especially against phones boasting much larger batteries. Instead, the Galaxy S26 Ultra turned in a standout performance and finished in third place overall.
What makes the result especially interesting is that the Galaxy S26 Ultra managed to outlast the iPhone 17 Pro Max (non-eSIM version) despite having only a modest advantage in battery capacity on paper. That points to something many buyers care about more than raw mAh numbers: efficiency. Optimization across the chipset, software, display tuning, and background power management can make a major difference in how long a phone lasts, and this test suggests Samsung has done serious work in that area.
The only devices that lasted longer than the Galaxy S26 Ultra were the OPPO Find X9 Pro and OnePlus 15—both equipped with silicon-carbon batteries and significantly higher capacity cells. In other words, it took much bigger batteries and newer battery chemistry for competitors to pull ahead, while Samsung still delivered 12 hours of runtime on a 5,000mAh pack.
Here are the recorded runtimes from the battery drain test:
OPPO Find X9 Pro (7,500mAh) – 14 hours and 16 minutes
OnePlus 15 (7,300mAh) – 12 hours and 55 minutes
Samsung Galaxy S26 Ultra (5,000mAh) – 12 hours
Apple iPhone 17 Pro Max non-eSIM (4,823mAh) – 11 hours and 32 minutes
Xiaomi 17 Ultra (6,800mAh) – 11 hours and 27 minutes
Samsung Galaxy S25 Ultra (5,000mAh) – 10 hours and 43 minutes
Google Pixel 10 Pro XL (5,200mAh) – 9 hours and 53 minutes
Another detail worth noting: the Galaxy S26 Ultra also showed a meaningful improvement over the Galaxy S25 Ultra, even though both share the same 5,000mAh battery size. That’s a strong signal that Samsung’s gains are coming from better efficiency rather than simply increasing capacity.
For anyone who has been on the fence about the Galaxy S26 Ultra because of the unchanged battery rating, this kind of real-world battery test helps reframe the conversation. Bigger numbers can be appealing, but day-to-day battery life is what matters—and the Galaxy S26 Ultra appears to be one of the strongest performers among current premium flagships.
