Thanks for the good discription. I have changed the Akku from my iPphone 6+ and the 6 from my brother, but now is my question how we can reset the batterie in iOS, because we can’t see the max. capacity of our Akku.
Before the update iOS 11.3 is available, I used an app to check the capacity and the apps works great before and after changed of my akku. I used an alternative Akku in my phone and an original Akku in the phone from my brother and we have the same problem.