iPhone 17 Pro Max vs Samsung S26 Ultra Battery Test

The 2026 battery test features a comparison between traditional lithium-ion "beta" devices and high-density silicon-carbon "alpha" devices.

The beta group consists of the Samsung S26 Ultra with 5,000 mAh, the iPhone 17 Pro Max with 4,823 mAh, and the Google Pixel 10 Pro XL with 5,200 mAh.

The alpha group includes the Xiaomi 17 Ultra at 6,800 mAh, the OnePlus 15 at 7,300 mAh, and the Oppo Find X9 Pro at 7,500 mAh. To bypass international shipping regulations that restrict large single-cell batteries, brands like OnePlus and Oppo utilize a dual-cell silicon-carbon architecture.

Regarding thermal performance and efficiency, the Samsung S26 Ultra and iPhone 17 Pro Max switched from titanium to aluminum frames to improve heat conductivity. During heavy stress tests, the Oppo Find X9 Pro became the hottest device, reaching 42°C and experiencing a performance drop due to its MediaTek chipset.

Conversely, the Google Pixel 10 Pro XL was consistently the hottest during moderate use and ultimately delivered the lowest performance scores, falling behind even the previous year's Samsung S25 Ultra.

The final endurance results saw the Oppo Find X9 Pro win with 14 hours and 16 minutes of life, followed by the OnePlus 15 at just under 13 hours.

The Samsung S26 Ultra lasted 12 hours, while the iPhone 17 Pro Max lasted roughly 10 hours and 50 minutes, narrowly beating the Xiaomi 17 Ultra. The older Samsung S25 Ultra finished in sixth place, and the Google Pixel 10 Pro XL came in last.

Notable features mentioned include the super power-saving modes on Oppo and OnePlus that extend core functionality at 1% battery.