By Orlando, 24 September, 2021 Forum iOS and iPadOS Hello O, I am using an iPhone 8 Plus and I recently updated to iOS 15. After about six hours my phone has gotten down to about 40%. After being charged to 100% overnight. Is anybody else experiencing battery drain issues with their device? Options Log in or register to post comments Comments Battery Using 12 pro. No issues here. Check your battery to see how it is doing. If is below 70%, you might consider changing it.