In the world of top-tier smartphones, battery life remains one of the key buying factors: how long a device can last without a charger during real use such as gaming, streaming, browsing, and shooting video. The YouTube channel TechDroider conducted an intensive test of three major 2025 flagships: the OnePlus 15, the iPhone 17 Pro Max, and the Xiaomi 17 Pro Max. The devices were put through a mixed workload designed to replicate a typical user’s day. The results were surprising: despite the huge batteries in the Android models, the OnePlus came out on top not only in overall runtime but also in compactness.

Test Methodology: From PUBG to 4K Video

TechDroider selected a realistic load pattern: three hours of PUBG Mobile at maximum settings, three hours of HD YouTube streaming, one and a half hours of web browsing and messaging on social media, and then continuous 4K 60 fps video recording until shutdown. The tests were conducted at room temperature of twenty-three degrees Celsius, with display brightness at fifty percent and Wi-Fi enabled. All smartphones started at full battery with no background apps.

The OnePlus 15 and Xiaomi 17 Pro Max use the Qualcomm Snapdragon 8 Elite Gen 5, while the iPhone uses Apple’s A19 Pro. This makes it possible to compare not just battery capacity but also the efficiency of each platform’s optimization.

Results: OnePlus Ahead by Half an Hour

The OnePlus 15, equipped with a 7300 mAh battery, lasted thirteen hours and forty minutes, achieving the best result. The Xiaomi 17 Pro Max, despite its larger 7500 mAh battery, managed twelve hours and fifty minutes, falling behind by nearly an hour. The iPhone 17 Pro Max, with a notably smaller 4832 mAh battery, delivered an impressive thirteen hours and two minutes, outperforming the Xiaomi but still trailing the OnePlus.

The difference was most noticeable during video recording: the OnePlus was able to record 4K at sixty frames per second for two hours longer than the Xiaomi. The iPhone, despite its lower capacity, showed strong performance thanks to the A19 Pro’s optimization, with iOS handling background activity and power consumption more efficiently.

Thickness and Weight: Compactness as an Advantage

Battery life is not the only factor. TechDroider also measured size and weight:

  • OnePlus 15: 8.1 mm thick and 215 g, the lightest and thinnest
  • Xiaomi 17 Pro Max: 8 mm and 219 g, the thinnest but slightly heavier
  • iPhone 17 Pro Max: 8.8 mm and 233 g, the heaviest

The OnePlus combines a large battery with a compact body, benefiting from an efficient LTPO display ranging from one to one hundred twenty hertz and optimization in OxygenOS 16.

Why the Results Turned Out This Way

The fifty-minute gap between the OnePlus and the Xiaomi comes down to software differences: Xiaomi’s ColorOS 16 manages background apps aggressively but reduces screen brightness during gaming. The iPhone benefits from iOS 19’s optimization, while the Snapdragon 8 Elite Gen 5 provides raw performance advantages on Android. All models support fast charging above one hundred watts, completing a full cycle in thirty to forty minutes.

Summary

The OnePlus 15 leads in battery life at thirteen hours and forty minutes among the 2025 flagships, ahead of the Xiaomi 17 Pro Max at twelve hours fifty minutes and the iPhone 17 Pro Max at thirteen hours two minutes. The test included PUBG, YouTube, browsing, and 4K video recording. The OnePlus is also thinner at 8.1 mm and lighter at 215 g. The difference comes from optimization, with the Snapdragon 8 Elite Gen 5 and OxygenOS working particularly efficiently. For maximum battery life, the OnePlus is the best choice; for ecosystem benefits, the iPhone remains preferable.