OnePlus has taken a dramatic leap with the OnePlus 15, equipping it with a 7,300 mAh silicon-carbon battery — nearly 50% larger than the 5,000 mAh units found in most 2025 flagships such as the Samsung Galaxy S25 Ultra and Google Pixel 9 Pro. Extensive real-world testing confirms that this is currently the longest-lasting smartphone available.
Unmatched Battery Performance
When subjected to extreme conditions — 165 Hz refresh rate, maximum brightness of 1,800 nits, 4K video recording, high-end gaming, and constant 5G usage — the OnePlus 15 consistently delivered over 36 hours of runtime, ending the test period with 18% remaining.
A particularly revealing test involved draining the device to 2% and then playing the demanding game Dead Cells continuously. The phone sustained gameplay for more than 45 minutes before entering emergency power-saving mode at 1%. Under more typical usage patterns (120 Hz refresh, adaptive brightness, mixed 5G/Wi-Fi), the OnePlus 15 regularly achieves two full days of use, and up to two and a half days with lighter workloads.
Flagship-Level Performance
The massive battery is paired with Qualcomm’s Snapdragon 8 Elite Gen 5, the fastest Android processor currently available. Benchmark results include:
- 3DMark Wild Life Extreme scores and frame rates approximately double those of the iPhone 15 Pro Max
- Geekbench 6 multi-core performance surpassed by only the latest iPhone 17 series
- Excellent sustained performance enabled by an advanced vapor-chamber cooling system
Display, Cameras, and Charging
The 6.78-inch OLED display offers 2,722 × 1,272 resolution, an adaptive refresh rate up to 165 Hz, and peak brightness of 1,800 nits, providing excellent visibility even in direct sunlight.
The camera array consists of a 50 MP main sensor with OIS, a 48 MP ultrawide, and a 64 MP 3x periscope telephoto, delivering strong results across zoom ranges and low-light conditions.
Charging capabilities are equally impressive: 100 W wired charging reaches 100% in approximately 32 minutes, while 50 W wireless charging and reverse wireless charging are also supported.
Trade-offs
The large battery contributes to a taller, thicker design and a weight of 228 g, making it noticeably heavier than competitors. Software support includes four years of OS updates and five years of security patches — respectable, but shorter than the seven-year commitments from Google and Samsung.
Conclusion
For users prioritizing battery life above all else, no 2025 flagship comes close to the OnePlus 15. Its combination of extreme endurance, top-tier performance, a vibrant high-refresh display, and capable cameras makes it one of the most practical superphones of the year.
The 7,300 mAh battery doesn’t just set a new standard — it shatters the old one.
(Details and test results sourced from CNET’s hands-on review of a global retail OnePlus 15 unit.)