Chosen Solution

The tiny yellow clip that holds the battery in my Nikon J1 has broken. I would like to know how to fix it and what that part is offically called

This little plastic part could be actually bought for around $10 from a seller on eBay. But looks like it is out of stock now. The part number is 1K684-884. Alternative solution: buy the extension grip Nikon GR-N2000 or its Chinese knock-offs available on AliExpress. They might help, as they should press strong enough against the battery door and keep the battery in place.