After following the method of determining the iPod's battery life (http://support.apple.com/kb/HT1322), I came up with these results: 17 hours, 9 minutes of music playback with 20% battery percentage left. Wifi - Off Bluetooth - Off Location Services - Off Push Notifications - Off Brightness at its lowest. Only music. My question is, is this normal? or my battery is defective? Thank you in advance.