https://wccftech.com/apple-replaced-11-million-batteries-2018/

Thanks to the $29 battery replacement program that Apple introduced after it released a statement summarizing that it was throttling the performance of iPhones, a lot of customers replaced the cells in their devices to bring them to their original performing state. With the $29 price reduction, down from $79, the report states that the company replaced 11 million batteries in 2018, with this figure being absurdly higher than the number that’s usually recorded when replacing batteries in a calendar year.

Apple released its Q1 2019 guidance, where Tim Cook stated that the company expects revenue of $84 billion, down from $89-$93 billion. According to Daring Fireball, who heard the information from an unnamed source, Apple normally replaces between 1-2 million batteries per year, with the number climbing to 11 million in 2018. The report also states that the true effect of the battery replacement program did not become apparent to Apple after it launched its iPhone XS and iPhone XS Max, followed by the iPhone XR.