Impressive battery hardware
Despite the multitude of exciting hardware on board, it’s the battery that’s the most important pillar of a modern smartphone, and objectively, the most important hardware element that matters in the long run.
And while the battery is impressive, it’s the efficiency and performance of the Snapdragon 8 Elite Gen 5 that also has a lot to play in the exceptional battery life. OnePlus has optimized it very elegantly with stability in mind.
For example, it doesn’t achieve crazy-high scores in 3D stress tests and doesn’t hit excessive fps figures but gives us one super-stable gaming experience.
The phone with the best battery life we’ve ever tested
The OnePlus 15 achieves a battery life estimate of ten hours and 44 minutes, which is a compound score combining three different tests. It hits a little over thirty hours in our custom web browsing test, twelve and a half hours in our video playback test, and finally, over 14 hours in our 3D gaming test. Some very respectable figures here, which are enough to put the OnePlus 15 at the very top of the leaderboard.
Right beneath it is the recent ASUS RedMagic 11 Pro, which is equipped with an even larger 7,500 mAh battery but loses by one minute in the compound battery life estimate score. Older excellent performers like the ASUS Zenfone 10, the Sony Xperia 10 IV, and the Nubia Z800 Ultra also complete the Top 5.
What about other current 2025 flagships? How do they perform against the OnePlus 15?
Well, the gap here is even wider, with the OnePlus 15 sitting nearly uncontested at the top of the battery life hall of fame.
Also, aside from the Vivo, the OnePlus is the fastest charging phone here, achieving a full charge in just 45 minutes, with a 30-minute charging session getting you nearly 70% of battery life, which should be more than enough for a day and a half of moderate to high usage. Pretty impressive.
Conclusion: Is this the best OnePlus phone ever?
While it’s true that the OnePlus 15 steps back from the original tenets that OnePlus stood by, it’s challenging to find any true faults here when it delivers so well in a couple of very important aspects.
The excellent battery life makes this phone the one that power users should shortlist. The era of two-day phones is here, and it’s only getting started! Who knows what 2026 could deliver, but one thing is for certain: the OnePlus 15‘s battery life record in our test might fall sooner rather than later.
