Beyond the Percentage: What Your Smartphone's Battery Health Number Isn't Telling You
That 80% battery health figure on your smartphone may look reassuring, but the chemistry happening inside your lithium-ion cell tells a far more complicated story. From SEI layer buildup to lithium plating, the real mechanisms of battery aging are largely invisible to consumers—and the consequences show up long before any diagnostic tool flags a problem. Here is what you should actually be watching.