Replaced my Dad's old iPod mini battery (wouldn't keep a charge) to give it a second life, cost me $10. I have an iPhone already but like the retro '00s look :
Charge the iPod the First Time - iPod: The Missing Manual, 7th Edition [Book]
Check the status light and battery charge on your iPod shuffle - Apple Support
Check Battery Status of Connected Devices from iOS Notification Center | OSXDaily
Charge your AirPods and learn about battery life - Apple Support
Check the status light and battery charge on your iPod shuffle - Apple Support
How to check AirPods Battery on iPhone, Watch, Mac, and Android
How to check AirPods Battery on iPhone, Watch, Mac, and Android
How to Get battery status on your iPhone & iPod Touch « Smartphones :: Gadget Hacks
New iPod Nano - How to check iPod Nano s battery status - YouTube