Microsoft recently updated the Battery Saver app of Windows Phone 8.1 with new features including live tile and the battery saver shortcut in the action center. But, these two features required a new build of Windows Phone 8.1. The new build is also available for download now which means you can finally get the live tile for Battery Saver and add it to action center as well.
The live tile as expected shows the battery percentage of your phone when the Battery Saver app tile is pinned to the Start Screen of your Phone. The tile only shows the battery percentage and the battery saver icon if, you have enabled it.
Coming to the shortcut for Battery Saver app in action center, it works as a toggle switch for different battery saver modes including less than 20%, until charge, battery saver and turned on – anyone of them can be selected.
No new features can be seen in the th1 14203 build of Windows Phone 8.1.1 other than these two Battery Saver options.