When the Apple Watch was announced, one of the biggest concerns was its battery life. Any smartwatch that can’t guarantee more than a day of performance is definitely a concerning topic for everyone. Now, what users weren’t prepared for is for the iPhone to not behave the same way after pairing the Apple Watch, and mixed results have arrived.
On one hand, a certain batch of users have praised the Apple Watch for helping the iPhone perform better in the battery department. It makes sense that if you spend more time on the watch, that as a result, this subtracts the amount of time you need the iPhone’s display to be active. By contrast, other users have complained about terrible battery life on the iPhone since pairing the Apple Watch. Most of these users have noticed that the iPhone’s companion app is to blame, and claiming that when they force close the app, battery life improves on their phone.
Sadly we don’t have specific information on which iPhones or Apple Watch models have been affected by this in a statistics level, but we should learn more as the days go by.
Source: Mac Rumors