How to upgrade an iPod for 2018 with flash memory and a new battery - The Verge
Amazon.com: i-Blason Battery Case Designed for iPod Touch 7/6/5, 2200mAh Portable Charging Rechargeable Extended Battery Slider Case for iPod Touch 5th/6th/7th Generation, Black : Electronics
Internal Battery for Apple iPod 4th Generation MP102 616-0206 616-0183