Adimorah JudeSmartphone batteries keep getting bigger every year, but real-life endurance doesn’t always match the numbers on paper. In a new extreme battery comparison by popular tech YouTuber MrWhoseTheBoss, the OPPO Find X9 Pro proved that capacity and optimization together make all the difference.
The Find X9 Pro, which launched alongside the standard Find X9 last year, packs a massive 7,500mAh battery — one of the largest ever seen in a mainstream flagship. And this time, it didn’t just look impressive on paper. It dominated.
The Ultimate 2026 Flagship Battery Endurance Test
To determine the best battery performer of 2026 so far, seven flagship phones were pushed through a continuous heavy-usage test including gaming, video streaming, social media scrolling, and benchmark stress tests.
The phones tested included:
- Samsung Galaxy S26 Ultra (5000mAh)
- Google Pixel 10 Pro XL (5200mAh)
- iPhone 17 Pro Max (4823mAh)
- OnePlus 15 (7300mAh)
- Xiaomi 17 Ultra (6800mAh)
- Samsung Galaxy S25 Ultra (5000mAh)
- OPPO Find X9 Pro (7500mAh)
Just two hours into the test, early signs already pointed toward OPPO’s dominance. The Find X9 Pro had dropped only 6%, while some rivals with smaller batteries were already showing noticeable decline.
Interestingly, despite sharing the same 5000mAh capacity, the Galaxy S26 Ultra outperformed the Galaxy S25 Ultra — likely thanks to better chipset efficiency and software optimization.
Gaming, Benchmarks & Heat Test
All devices were first subjected to one hour of intensive gaming, followed by benchmark stress tests that pushed temperatures up to 42°C on some phones.
This is where optimization separated the winners from the rest.
The Xiaomi 17 Ultra, despite its large 6800mAh battery, failed to impress. Around the 9-hour mark, it had already dropped roughly 80% — performing worse than devices with smaller batteries like the Galaxy S26 Ultra and iPhone 17 Pro Max.
The first phone to shut down was the Pixel 10 Pro XL. It was followed by the Galaxy S25 Ultra, then the Xiaomi 17 Ultra and iPhone 17 Pro Max. The Galaxy S26 Ultra lasted longer, narrowly behind the OnePlus 15. But the real winner wasn’t even close.
Final Results: OPPO Wins by a Landslide
The last three phones standing were:
- OPPO Find X9 Pro — 14 hours 16 minutes
- OnePlus 15 — 12 hours 55 minutes
- Galaxy S26 Ultra — 12 hours
The OPPO Find X9 Pro outlasted every competitor by a significant margin, crossing the 14-hour mark before finally shutting down. While it wasn’t the coolest device in terms of thermals, it still performed better than the Pixel 10 Pro XL under heat stress.
Why Did Xiaomi Underperform?
The Xiaomi 17 Ultra’s results were surprising given its battery size. Reports suggest that Xiaomi may have limited battery capacity in certain regions to meet shipping regulations, which could explain the underwhelming performance during the battery endurance test.
Meanwhile, the iPhone 17 Pro Max used in this test was the UK variant. The US eSIM-only model houses a slightly larger battery, meaning performance may vary by region.
Should You Buy the OPPO Find X9 Pro for Battery?
If battery life is your top priority, the OPPO Find X9 Pro is easily one of the best flagship choices in 2026. With a 7,500mAh battery and solid optimization, it delivers true multi-day usage under moderate conditions.
For heavy users, gamers, and content consumers, this might just be the ultimate battery phone of the year.
