iPhone 14 Battery Draining after update

There could be several reasons why your iPhone 14 Pro Max is experiencing battery drain after updating to iOS 15.3.1. Here are some steps you can take to try and fix the issue:

1. Check Battery Usage: Go to Settings > Battery > Battery Usage to see which apps are using the most battery. If you see an app using a lot of battery, try force-closing the app or deleting it and see if it helps.
2. Turn Off Background App Refresh: Go to Settings > General > Background App Refresh and turn off the switch to prevent apps from refreshing in the background.
3. Turn Off Location Services: Go to Settings > Privacy > Location Services and turn off location services for apps that don't need it. You can also turn off the "Precise Location" setting to improve battery life.
4. Reduce Screen Brightness: Go to Settings > Display & Brightness and turn off "Auto-Brightness" and reduce the screen brightness.
5. Turn On Low Power Mode: Go to Settings > Battery and turn on "Low Power Mode" to conserve battery life.
6. Update Apps: Make sure all your apps are up-to-date, as older versions of apps can sometimes cause battery drain.
7. Reset Your iPhone: If none of the above steps work, you may need to reset your iPhone to factory settings. Before doing so, make sure to backup your data to iCloud or iTunes.

If you've tried these steps and your battery life is still poor, you may want to contact Apple support or visit an Apple Store to get further assistance.