Ok hopefully this story isn’t too confusing. I and another person got iPhone 7+ at the same time. 9 months later hers got audio loop disease so I switched with her as I always use blue tooth. I was surprised that as we switched my battery life was 96% and hers was 89 %. That was two months ago. I bought her a new XR so I got my phone back. In that two months my phone went from 96 to 89%. Her iPhone 7 Plus that I used for those two months only went from 89 to 88% life. How the hell is she so hard on batteries??