10 reasons why your phone battery keeps dying

 The screen brightness is set too high

A major source of battery drain is setting the screen brightness too high. Either dial it back and keep it at a low setting all the time, or take advantage of the setting that enables the phone to automatically determine how bright the screen should be based on your surroundings. Your phone will adjust to make your text messages visible when it’s bright outside, but you won’t be wasting precious battery power looking at the same level of brightness when you’re indoors. Another way to reduce the amount of battery power consumed by your screen is to shorten the amount of time that it’ll take for the display to turn off after you stop using it.