Apple iPod nano (5th generation) - Manual (Page 18)

18 Chapter 1 iPod nano Basics
When iPod nano is connected to a power source, the battery icon changes to show
that the battery is charging or fully charged.
You can disconnect and use iPod nano before it’s fully charged.
Note: Rechargeable batteries have a limited number of charge cycles and might
eventually need to be replaced. Battery life and number of charge cycles vary by use
and settings. For information, go to www.apple.com/batteries.
Improving Battery Performance with Energy Saver
Energy Saver can extend the time between battery charges by turning off the
iPod nano screen when you aren’t using the controls.
Energy Saver is turned on by default.
To turn Energy Saver on or off:
m Choose Settings > Playback > Energy Saver, and then select On or Off.
If you turn Energy Saver off, iPod nano displays the following information after the
backlight turns off:
Turning off Energy Saver increases the rate of battery consumption.
Battery charging (lightning bolt)
Battery fully charged (plug)