How the battery score is calculated

Expected battery life from specifications: battery capacity (60%, required), battery capacity per inch of screen (20%), chip manufacturing process (10%), ltpo variable refresh display (10%).

Estimated from specifications, not from a battery rundown test. Real endurance also depends on software tuning.

Inputs, weights and scales for the battery score (formula version 2.6). Values between two points are scored on the straight line between them; values beyond the ends get the end score.
InputWeightRequiredScale: value → points
Battery capacity60%yes4,000 mAh → 0 · 5,000 mAh → 40 · 6,000 mAh → 65 · 7,000 mAh → 85 · 8,000 mAh → 100
Battery capacity per inch of screen20%no600 mAh/inch → 0 · 750 mAh/inch → 40 · 900 mAh/inch → 70 · 1,050 mAh/inch → 90 · 1,200 mAh/inch → 100
Chip manufacturing process (smaller is more efficient)10%no3 nm → 100 · 4 nm → 75 · 5 nm → 55 · 6 nm → 35 · 12 nm → 0
LTPO variable refresh display10%noyes = 100, no = 0

Worked example

The Redmi Note 17 Pro Max is #3 in the current battery list. Its battery score of 100 comes from these inputs:

Redmi Note 17 Pro Max: battery score step by step. Points are on the 0 to 100 scales above.
InputThis phonePointsWeightContribution
Battery capacity10,000 mAh battery10060%75.0
Battery capacity per inch of screenworked out from other specifications10020%25.0
Chip manufacturing process (smaller is more efficient)not confirmed—10%left out
LTPO variable refresh displaynot confirmed—10%left out

The contributions add up to the score. An input that is not confirmed is left out and the remaining weights are scaled up to 100%, except where the category counts an unknown input at the middle of its scale (shown as "counts as 50").

See the ranking.

Full methodology