While Greater China and other emerging markets accounted for the vast majority of the year-over-year iPhone revenue decline, in some developed markets, iPhone upgrades also were not as strong as we thought they would be. While macroeconomic challenges in some markets were a key contributor to this trend, we believe there are other factors broadly impacting our iPhone performance, including consumers adapting to a world with fewer carrier subsidies, US dollar strength-related price increases, and some customers taking advantage of significantly reduced pricing for iPhone battery replacements. 

Apple Website

Like many I can't say the last line that iPhone battery replacements made a significant impact to lower sales than previous projected, it's a bad look Tim. The smartphone market is mature and for the most part fully saturated. Someone like myself, who has pre-ordered most iPhones, getting the newest biggest best, have held off in recent cycles. Why? The combination of phones breaking $1,000, with the leveling off of hardware speed from year to year. Even with that, I've been Apple Leasing iPhones since they offered it. Pretty much iPhone as a service. At this point every 2 years seems more than adequate.