Why Your Phone Battery Slowly DIES Even If You Baby It

Your phone battery is quietly dying right now, and there is nothing you can do to fully stop it.

Why does a battery hold less charge every year, even one you treat perfectly?

Every lithium battery grows a microscopic crust on its graphite side called the SEI layer. It forms on the very first charge and it is actually necessary, because it protects the electrode from the electrolyte. But each charge cycle, it thickens slightly, and every time it grows, it permanently traps a few lithium ions inside itself. Those ions can never shuttle again. Since the total number of usable ions is what defines your capacity, every trapped ion is capacity gone forever. Multiply that by hundreds of cycles, and the shelf slowly loses its stock.

So your battery does not wear out like a worn tire. It starves. The exact layer that keeps it safe is also quietly eating its fuel, and heat and fast charging just let it eat faster.

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