When asked to comment about the long wait times, Apple pointed to its support site. Different models can have different wait times. Some of the phones covered by Apple's replacement program — the iPhone 6 and iPhone 6 Plus — no longer are being manufactured, which means battery supply is limited. (Many of the people who have been complaining say they have the iPhone 6.) An internal document reportedly leaked to MacRumors about a week after the program launched warned even then that some of those batteries would not come in until March.

Source: Los Angeles Times February 20, 2018 19:41 UTC