Use your Galaxy S5 power-saving mode. Check for rogue apps. If all else fails, reboot or reset. How to get better Galaxy S5 battery life. One of the top questions we'll get this year regards Samsung Galaxy S5 battery life.
The Samsung Galaxy S5 offers two power saving battery modes – Power Saving and Ultra Power Saving. Power Saving is a fairly traditional mode that tweaks things like processor clock speed and screen brightness/contrast.
The longer you leave the interval gaps, the more battery life you will save. Try to keep your Samsung Galaxy S3 on charge whenever possible and never let the device run down to the point where it turns off.
Samsung's AMOLED displays keep getting more efficient, but the screen continues to be a notable drain on a phone's battery life. You can simply lower the screen brightness on your Galaxy S8 to save battery life — either by using the slider in the notification shade, or in settings then display.