回答“Hinge on the right is broken, is there any way to fix?”There are many compatible cases for the original nds now, so following these guides will point you in the right direction!
回答“xiaomi qicycle battery replacement”https://www.aliexpress.com/wholesale?cat... This is a link to a search for the battery on AliExpress, you can find many replacements, with prices starting at $219.99 (USD). The real problem with repair or recreation of these batteries is opening the unit without damaging it. I'd love to be able to open the battery unit and test the cells to see if one is faulty and preventing further charging. I'm a hair’s breadth from buying a replacement battery myself, as my battery won't charge anymore and Xiaomi don't support the cycle in my region. But that $219+ replacement price isn't a small amount, so I'm struggling on without the battery for the moment.