Battery Case for new IPhone SE

you can see what cases support the new SE here https://www.apple.com/shop/iphone/iphone-accessories/cases-protection?page=1#!&f=iphonese2&fh=458b%2B4c83

Apple says no, but some people say yes. You could try using your existing iPhone 8 case, but personally I don’t think Apple will use similar phone sizes for 2 different models. But if you wanted to buy everything at one go and to be safe maybe you should get the cases designed specially for the iPhone SE 2.