For non-Retina displays (3G, 3Gs, etc):
To display the reflection under the logo, go into /Bundles/com.springboard.app and change the filename BatteryReflectionMask.png
to BatteryReflectionMask.png1 



If the reflection is displayed and you don't want it, change BatteryReflectionMask.png1 to BatteryReflectionMask.png



For Retina displays (iPhone4, IPT4G):
To display the reflection under the logo, go into /Bundles/com.springboard.app and change the filename BatteryReflectionMask@2x.png
to BatteryReflectionMask@2x.png1 



If the reflection is displayed and you don't want it, change BatteryReflectionMask@2x.png1 to BatteryReflectionMask@2x.png



