In Android, as in other mobile operating systems like Windows or iOS, the status of the battery charge level is displayed through a small icon usually located in the upper-right corner of the device. As the level of battery charge changes, this battery icon also changes slightly to indicate the charge status. But you cannot really see the difference unless the charge level drops to a considerable level, for example, from 100% to 70%. If you want to have a much more clear indication of the battery charge level then you can use the free app Energy Bar.
Energy Bar can clearly display the battery level using two indicators – color and a long bar. It displays a long bar along the top edge of your Android device beside the status bar. The length of the bar indicates the battery charge status – longer the bar, higher the battery level. In addition, it also uses color indicator to tell you how much the battery level has dropped. The long bar is color coded using red, yellow, blue and green colors indicating the battery level of 0%-25%, 26%-50%, 51%-75% and 76%-100% respectively.
The app allows everything to be customized – you can change the position of the energy level bar, the origin of this bar, the thickness of the bar, the visibility of this bar, whether the bar should display animation when you are charging the device, and you can also customize the colors used to display the bar for various charging levels of the battery.
If you have an Android phone that has a considerably smaller capacity battery (2000 mAh or smaller) then Energy Bar app can be very useful for you as it can clearly indicate when your battery level has gone down and when you should connect the phone charger or a portable power bank.
You can get the Energy Bar app for Android from https://play.google.com/store/apps/details?id=you.in.spark.energy.