Battery life is a perennial problem for smartphone owners. While our handsets have become faster and more powerful over the years, smartphone batteries often last less than a day under heavy use, or even moderate use after a few months.
The lithium-ion battery has been around for more than two decades, and hasn't fundamentally changed since 1991. And despite lots of effort being put into replacements, these batteries are likely to be with us for many more years. Here's what you need to know about your smartphone's battery.