All of this will happen when you upgrade to iOS 14.5, so performance issues may disappear.
An official certified documents Based on this, Apple is trying to solve the downtime and performance degradation that some iPhone 11 mobile phone users complain. Apple is trying to solve this situation by recalibrating the battery.
All of this will happen when users upgrade to iPhone 11, iPhone 11 Pro and iPhone 11 Pro Max to iOS 14.5. Based on this information, it may take several weeks for the system to determine the remaining battery capacity and the performance that can still be guaranteed. A message will also notify the user.
This feature has been tested in the latest developer Beta. If recalibration encounters an error, Apple promises to replace the battery free of charge. Of course, it is difficult to say whether recalibrating the energy source can really solve the problem in every situation, or whether components need to be replaced in any situation.