ROG Phone 9 vs Xiaomi 15 Pro
A side-by-side readout for battery capacity.
What battery capacity means for this matchup
Battery capacity is a measured value in mAh. On this field, Xiaomi 15 Pro has the advantage because the higher value is preferred.Treat this page as one decision slice, then return to the full comparison before making a purchase.
Understanding battery capacity
Battery capacity is a numeric spec measured in mAh. On this metric, higher values are generally better, but returns diminish past category-typical thresholds — going from a low value to a mid value usually matters far more than going from a mid value to a high one. When comparing two products, focus on the percentage gap rather than the raw delta: a 200-unit lead means something very different at the low end of the range than at the high end. Pay attention to the unit, too — manufacturers sometimes quote peak or burst figures that are not sustained in real-world use. Cross-check the published number against independent measurements where possible, especially for performance and battery claims. Finally, remember that a single spec rarely tells the whole story; the Mars Score weighs battery capacity together with the rest of the spec sheet so one outlier doesn't distort the verdict.
This matchupXiaomi 15 Pro's 6100mAh is roughly 5% higher than ROG Phone 9's 5800mAh (a 300mAh gap). Whether that gap is noticeable depends on workload — small percentage gaps rarely change day-to-day experience, while gaps of 20% or more usually do.
Other specs on this comparison
See the full Smartphones category for all products ranked by Mars Score.