Hello there, DizDude.
The following Knowledge Base article offers up some good recommendations for troubleshooting battery issues with the 7th generation iPod Nano:
iPod nano (7th generation): Hardware troubleshooting
http://support.apple.com/kb/TS4433
Particularly this section:
Learn how to conserve battery life.
- Ensure that the latest software is installed on the iPod.
- When charging, use the cable that came with iPod nano (7th generation) and leave the device connected until it is fully charged.
Note: If you are charging using your computer, don't connect iPod nano (7th generation) to your keyboard. Also, the computer must be turned on and not in sleep or standby mode. If iPod nano (7th generation) is connected to a computer that's not turned on or is in sleep or standby mode, the iPod nano (7th generation) battery may drain.
- When you are done using the iPod nano, verify that:
- The Radio application is off (tap the button)
- Music is paused (tap the button in the iPod application or disconnect the earphones)
- There is no active Pedometer session (tap the Stop button in the Fitness application)
- Dimming the screen is another way to extend battery life on iPod nano. Go to Settings > General > Brightness and restore the brightness to the default, or drag the slider to the left to lower the default screen brightness.
- Playing tracks with EQ requires your iPod processor to consume more energy than playing tracks without EQ, because the EQ information is not encoded in the song. To prolong battery life, turn EQ off if you don't use it. Go to Settings > Music > EQ and select Off from the list. Note, however, that if you've added EQ to tracks in iTunes, you'll need to set EQ to Flat to have the effect of Off, because iPod keeps your iTunes settings intact.
- Try restoring iPod nano (7th generation) by connecting it to iTunes and clicking Restore.
- Test the battery life.
Thanks for reaching out to Apple Support Communities.
Cheers,
Pedro.