Hello there, popvalleyboy.
The iPod Shuffle tech specs provide a good overall answer to standard usage provided by a fully charged battery:
Apple - iPod shuffle - Technical Specifications
By leaving it on pause, it sounds like you're already using some of the great pointers for maximizing battery performance on the iPod mentioned here:
Apple - Batteries - Maximizing Performance
Always make sure your iPod is using the latest version of Apple software. Put your iPod in its dock or plug it into your computer, and iTunes will notify you of available updates.
Hold and pause. Set the Hold switch when you’re not using your iPod. This will prevent iPod from accidentally waking up and using unnecessary power. If you’re not listening to your iPod, pause it, or turn it off by pressing the Play button for two seconds.
Equalizer (EQ). Adding EQ to playback increases use of your iPod processor, since EQ isn’t encoded in the song. Turn EQ off if you don’t use it. If, however, you’ve added EQ to tracks in iTunes, you’ll need to set EQ to “flat” in order to have the effect of “off,” because iPod keeps your iTunes settings intact.
Backlight. Setting the backlight to “always on” will significantly reduce your battery life. Use the backlight only when necessary.
Make sure your computer is plugged in and powered on when you’re using it to charge your iPod via USB. If your iPod is connected to a computer that’s turned off or is in sleep or standby mode, the iPod battery may drain.
Thanks for reaching out to Apple Support Communities.
Cheers,
Pedro.