Exposing the sneaky math behind your Android phone’s battery life claims in 2026

Battery degradation is perhaps the biggest concern if you want to keep a phone for three years or longer. Fast degradation means terrible battery life after just a year or two. This wasn’t a huge deal in the late 2000s and early 2010s, since user-replaceable batteries let you easily switch to a new cell. But we now live in an era where most people have to take their phone to a repair center to get the battery replaced.

It used to be relatively easy to understand the battery degradation information smartphone makers disclosed. Unfortunately, I’ve noticed that some mobile brands are quietly trying to redefine how degradation is measured. But why?