Dozens of user reports on the Apple support community claim that their iPhones are suffering from expedited battery drain on iOS 11.4.
Specifically, the issue has been reported on older iPhones including the iPhone 6, iPhone 6s, iPhone 6s Plus and iPhone SE. The issue occurs regardless of if users have recently replaced their device’s battery — some iPhone owners were told that they should get their battery replaced even after recently getting a replacement.
For now, moderators have suggested that turning off location services and keeping Wi-Fi on to ameliorate the situation, but it’s no fix.
The first report was made on June 2. Apple released iOS 11.4.1 today along with corresponding updates to macOS, watchOS and tvOS. No anecdotes on if that update has solved anything yet.