Apple's repair chain is limited to Apple's official stores and Apple Authorized Service Centers. This is, of course, speaking of company-repaired repairs, as you may very well choose to perform such repairs on ordinary technical assistance or even on your own. Think about drumsIt's a fairly common component and one that necessarily needs to be replaced if you spend more than three years with your smartphone.
The problem is that if you did that (replace the battery) with a regular service or on your own, Apple would then deny any kind of repair to your device. Example: you have an iPhone 6s and decided to change the battery yourself; but recently dropped the device and broke the screen. By taking the iPhone into an Apple Store, the company gave itself the right to deny the repair. Fortunately, that has changed.
According to the iGeneration (Google Translate), if the repair is not battery related (as in the case described above), both Apple and Apple Authorized Service Centers have accepted services normally, according to a new internal Apple document. This includes repairs to the screen, logic board, microphones, cameras, etc.
If the repair is related to a replacement battery, Apple and the CSAA may replace it in question with an official (obviously charging for it). Probably for safety's sake, Genius were instructed to drain third party batteries to less than 60% when performing such repair.
If there is any damage to the battery or excess stickers, Apple and CSAA may replace the entire iPhone by charging only the cost of replacing the battery, which of course will be a decision of the employee concerned.
Updated guidelines are already valid at least in the United States and should be spreading globally soon. I mean, not in every country. In France, this new guideline has been challenged by Ma retailers because they have not been properly consulted on the issue and believe that this new policy raises important safety issues as these third party batteries may have questionable quality and may even explode at the moment. of repair.
Note that Apple still gives itself the right to refuse services on iPhones with logic boards, frame, microphones, Lightning connectors, headphone plugs, volume buttons, sleep buttons, sensors or any other components (other than battery or screen) from third parties.
Update 3/6/2019 16:34
O 9to5Mac He also had access to the document with the new guidelines and shared some more interesting information about it.
The fact that the user exchanges the Apple battery for a non-original battery does not necessarily violate the warranty terms of the device. However, if such a battery is responsible for a device problem, the customer will have to pay the cost of repair / replacement.
Incidentally, it is worth clarifying what are third-party batteries: we are talking about components created by companies that do not supply Apple (but still produce quality parts) or even counterfeit batteries.
Notwithstanding, even accepting iPhones as such to make repairs, Apple is entitled to charge for the device if the repair in question is not successful.