We have something similar in The Netherlands. Had a 2015 13" battery replaced that started bulging a few months ago, for free, within a few days. The battery wa

We have something similar in The Netherlands. Had a 2015 13" battery replaced that started bulging a few months ago, for free, within a few days. The battery was functioning fine, it didn't have many cycles, yet bulged anyway (all the cells did) to the point the bottom started to pop open. While I wouldn't have a problem replacing this battery myself with an iFixit kit or reviewed eBay stuff, after some measurements and checking this really had to be a manufacturing issue; so up to Apple to take care of (and they did).