Apple recently announced that it was expecting revenues to take a hit, as a result of several factors. Economic slowdown and increased competition from China were blamed but another cause seems to be the company’s discounted battery replacement program.
Apple may have been expecting to replace between one and two million batteries for the year but things didn’t work out that way. According to John Gruber of Daring Fireball, in 2018 Apple had to contend with some 11 million iPhone battery replacements. Because reasons (to do with software throttling). That’s a lot of older iPhones that were good to go for at least another year, meaning that users didn’t really need to upgrade. At least a few of them probably didn’t.
A higher-than-expected number of users replacing batteries in older phones as opposed to upgrading their devices would have put a dent in Apple’s final results for the year. This still could have come as a surprise because “… the effect of the battery replacement program on new iPhone sales [probably] wasn’t apparent until after the iPhone XR and XS models were available.”
The information on how many batteries Apple replaced in 2018 reportedly came out during an all-hands meeting headed by CEO Tim Cook (the meeting itself was reported by Bloomberg) on 3 January. The specific contents of that meeting are unknown, except the bit about batteries picked up by Gruber.