Various Batteries and Thin Cases - 5th Gen modding : r/ipod
Metal Back Case Housing 1900mAh Battery Hold Switch for iPod 6th Classic 80GB | eBay
Amazon.com: hkoem 128gb Thick Metal Back Housing Case Cover Headphone Audio Jack Hold Switch 1900mAh Battery for iPod 6th 7th Gen Classic SSD Upgrade : Cell Phones & Accessories
128GB Back Housing Case 1900mAh Battery for iPod 6th 7th Classic SSD Upgrade | eBay