Phone Charging Myths, Debunked "Don't use your phone while it's charging," "don't leave it plugged in overnight" and "always let it die completely" — these are just a few popular myths about smartphone batteries. When it comes to battery life, there are many little rules for what you can and can't do with your smartphone. While plenty of real rules exist, there are several rumored ones you can simply ignore. Phone batteries have evolved so much over the years, becoming smarter and easier to manage. Most lithium-ion batteries, used by major retailers like Samsung and Apple, should last between three and five years, if you take proper care of it. Phone Charging Myths, Debunked "Don't use your phone while it's charging," "don't leave it plugged in overnight" and "always let it die completely" — these are just a few popular myths about smartphone batteries. When it comes to battery life, there are many little rules for what you can and can't do with your smartphone. While plenty of real rules exist, there are several rumored ones you can simply ignore. Phone batteries have evolved so much over the years, becoming smarter and easier to manage. Most lithium-ion batteries, used by major retailers like Samsung and Apple, should last between three and five years, if you take proper care of it.