From Thomas Baumann:
BattCursor shows the battery charge in percent directly under the mouse cursor, and offers many other battery-saving features, among others, dim down the display brightness for inactivity, automatically disable the Windows Sidebar and Aero Glass. The other functions help the battery runtime mainly to increase. Including dimming down the display brightness by inactivity and automatically disable the Windows Sidebar and Aero glass. BattCursor offers the possibility of an OSD for changes to the display brightness and volume display system, and thus it can replace some OEM software completely.