You can choose from three different levels of battery savings in this mode, although I was unable to make the phone go into ultra power saving mode on its own at any moment. (sammobile.com)
Baby call monitoring can last for 12 hours with power saving mode on and 8 hours with screen - on. (makeyourbabylaugh.com)
Have it your way: 124 miles in power saving mode, or 0 - 60 in 7 seconds in bat - out - of - hell sports car mode. (extremetech.com)