I have the iPhone 7 battery case and it is still working well and looking new. It makes a big difference. I am a very light phone user. However, I have noticed that my phone battery drain has been quicker lately, and I haven’t done anything different. I was getting much better battery life on iOS 13. I could easily make it 1 - 1. 25 days before needing got charge. With iOS 14, a lot of times I am already at 20 - 30% by the end of the day. It’s not a big deal but, I have started using my battery case more just to be on the safe side.