After slowing down phones performance controversy, Apple published a Message to Customers about “iPhone Batteries and Performance”.
Company is trying to retrieve customer’s trust and denied that did anything intentionally, which could shorten the life of any Apple product. Additionally, Apple provides more information about iPhone’s rechargeable battery and the factors affecting its performance.
Finally, out-of-warranty iPhone battery exchange price is $29 (reduced from $79) for any iPhone 6 or later if only battery should be replaced. Details supposed to be provided in near future.
New iOS software will be released in early 2018 to provide more information about iPhone battery. It should be useful for users, who are interested in verification whether any influence on phone performance coming from battery exist.