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In some cases, much of the battery drain happens in standby mode when the iPhone isn't in use, suggesting a background activity could be causing problems for some users. Using the phone seems to cut the battery drain in these instances.

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There are similar complaints about the iPhone 16 models and older iPhones running iOS 18 on Reddit, and while we always see reports of battery life issues when a new version of iOS comes out, there seems to be a definite uptick in the number of people having problems.