A flat phone battery is beyond frustrating, especially when we're out of the house and in need of our smartphones. Sometimes it feels like you're charging your phone for hours only to have it die in half the time. But why, exactly, is your phone battery draining so fast? What you might not know is that several things can eat away at your battery without you even realizing it, and taking control of them can keep your battery fuller for longer. So, here are the seven most common causes of a quick-draining phone battery.