MacRumors published usage records for iPhones capped at 80% charge. Battery health was 88% for a 36-month-old iPhone 15 Pro Max, 93% for a 24-month-old 16 Pro Max and 97% for a 12-month-old 17 Pro Max. The comparison involves different devices, charging-cycle counts and usage, with no control group charged to 100%, so it cannot quantify the charging limit’s causal effect. It is a reference case for the personal choice to trade daily available capacity for consideration of long-term battery life.