Is 80% Battery Health a Critical Threshold?

Many users believe that a used iPhone battery must be replaced once its health drops below 80%, but this is a partial misunderstanding of Apple’s official standards. While Apple does define "normal wear" as retaining ≥80% capacity after 500 charge cycles, it does not mean batteries below 80% are unusable.

For batteries with health between 70%-80%, if the cycle count is not excessively high (e.g., under 1000 cycles) and there are no issues like swelling or abnormal charging, they can still meet daily light usage needs (such as social media or web browsing). However, their battery life will be 1-2 hours shorter than batteries with 80%+ health. If health falls below 70%, or drops sharply from 80% to below 70% within a short period (3 months), it indicates accelerated cell aging—prompt replacement is recommended to avoid impacting user experience.

Additionally, the health percentage is only a reference; actual battery life depends on usage scenarios. For example, frequently playing graphics-intensive games or using 5G may result in shorter battery life even with 85% health compared to a 75% health battery used only for light tasks. When purchasing, it’s advisable to consider health percentage, cycle count, and actual battery life tests together rather than relying solely on the health number.