Hey Questers, 🌟

Battery life is no longer just a spec you glance at and forget. In today’s flagship phones, displays are already excellent, performance is more than sufficient for almost everyone, and cameras have reached a point where real differences only become apparent in very specific situations. What actually affects everyday use is much simpler: how long your phone lasts when you stop babying it and start using it properly. To find that out, we put three of the most powerful Android flagships of 2025 through a controlled six-hour battery drain test: the OnePlus 15, the iQOO 15 and the Realme GT 8 Pro. All three devices are powered by the Snapdragon 8 Elite Gen 5 chip, all sit in the same premium price bracket, and all promise top-tier performance. The real question was which one could hold on the longest once the workload became serious.

Test conditions

To ensure fairness, all three phones were connected to the same Wi-Fi network. Display brightness was calibrated to 500 nits using a lux metre, screen colour mode was set to Natural, resolution was locked to FHD+, and refresh rate was set to Adaptive. Audio volume was fixed at 50%, and each device was fully charged to 100% before testing. All phones were running their latest Android 16-based software builds.

Prices in India

OnePlus 15: Rs 72,999 (12 GB + 256 GB), Rs 79,999 (16 GB + 512 GB)

iQOO 15: Rs 72,999 (12 GB + 256 GB), Rs 79,999 (16 GB + 512 GB)

Realme GT 8 Pro: Rs 72,999 (12 GB + 256 GB), Rs 78,999 (16 GB + 512 GB)

Key specifications 

The OnePlus 15 features a 6.78-inch LTPO AMOLED display with a 1.5K resolution (1272 x 2772) and a 165Hz refresh rate. It peaks at 1,800 nits in high brightness mode and is protected by Gorilla Glass Victus 2. It runs OxygenOS 16 based on Android 16 and houses a 7,300mAh battery with 120W wired and 50W wireless charging.

The iQOO 15 uses a larger 6.85-inch LTPO OLED panel with a QHD+ resolution (1440 x 3168) and a 144Hz refresh rate. It is the brightest of the three at 2,600 nits HBM. It runs OriginOS 16 atop Android 16 and packs a 7,000mAh battery with 100W wired and 40W wireless charging.

The Realme GT 8 Pro comes with a 6.79-inch LTPS AMOLED display at QHD+ resolution (1440 x 3136) with a variable 60-144Hz refresh rate. Peak brightness is rated at 2,000 nits (HBM). It runs Realme UI 7.0 based on Android 16 and also has a 7,000mAh battery, with 120W wired and 50W wireless charging.

All three phones use the Snapdragon 8 Elite Gen 5 chip, up to 16 GB LPDDR5X RAM and 512 GB UFS 4.1 storage, aluminium frames, glass backs and IP68/69 dust and water resistance.

2 hours of YouTube video playback

We began with two hours of continuous YouTube video playback. Despite differences in resolution and refresh rate, all three displays looked excellent in real-world viewing. The Realme GT 8 Pro leaned towards a more natural, balanced colour profile. The OnePlus 15 also delivered pleasing colours, and its 1.5K panel clearly helped with efficiency

The iQOO 15 stood out visually. Its panel was noticeably brighter, with stronger highlights and punchier colours that held up better outdoors. All three performed well under direct sunlight, but the iQOO had the most visual impact.

1 hour of social media

The final hour consisted of continuous Instagram usage. By the six-hour mark, the OnePlus 15 finished with 50% battery remaining. The iQOO 15 wrapped up at 41%, followed by the Realme GT 8 Pro at 39%.

Total battery drain after 6 hours

OnePlus 15: 50% remaining (3,650mAh drained)

iQOO 15: 41% remaining (4,130mAh drained)

Realme GT 8 Pro: 39% remaining (4,270mAh drained)

Conclusion 

On paper, the OnePlus 15 wins this test by finishing with the most battery left. However, that result needs context. The phone crashed during both Antutu and 3DMark, meaning it did not endure the same workload as the other two devices. While it ran an extra CPU throttling test, that does not match the intensity of full GPU stress testing.

The Realme GT 8 Pro emerged as the most stable and consistent performer. It rarely spiked in temperature, completed every test, and delivered predictable results, though it lagged behind in raw performance.

The iQOO 15, however, proved to be the strongest all-rounder. It delivered the best sustained performance, the brightest display, excellent efficiency during video playback, and the most dominant gaming results. Yes, it drained more battery during benchmarks, but that was the cost of pushing higher performance without crashing.

thermals, display quality and real-world performance, the iQOO 15 is the phone that truly stands out in this three-way battle.

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Regards,

@Aman_karadbhajne