Apple has created a repair program for the iPhone 6s to address an issue that could cause the phones to shut down spontaneously. The fix is to replace the battery.
Apple says that the problem affects a very small number of iPhone 6s models manufactured between September and October 2015 with specific serial numbers. At first, Apple didn’t have a serial number checker available for this program, but they’ve since added one. Simply enter your device’s serial number on the repair program Web page to see if your device qualifies.
If your iPhone 6s is shutting down unexpectedly, you can schedule an appointment with an Apple Authorized Service Provider or the Genius Bar at your nearest Apple Store, or you can contact Apple Technical Support. As always, be sure to back up your iPhone to iTunes or iCloud before you take it in for service.
Apple didn’t say whether it would reimburse users who have already paid to have the battery replaced in these phones, perhaps because it affects so few people. That said, if you’ve had your iPhone 6s battery replaced because of this problem, contact Apple to see if the company will help.