Some iPhone users who have recently installed the iOS 16 update may feel that their battery is draining much faster than before. Especially when using applications like https://apps.apple.com/us/app/call-recorder-for-iphone/id1503665233 in the background. And truthfully, it is very well maybe! If your iPhone's battery is draining quickly after installing iOS 16, there's probably a reason for it, and luckily, it's usually one of the easiest things to fix.
1: Spotlight and photo crawling drain battery life
If you recently upgraded to iOS 16 and find that your battery life is much worse than usual, this is actually normal and expected behavior because the crawling activity continues in the background.
Every time you update the iOS system software, background tasks start and end. This includes everything from Spotlight, which re-indexes your phone's contents, including notes, photos, and app data, to the Photos app, which re-indexes and scans photos to find objects, faces, locations, and metadata.
These background operations and indexing methods consume power and thus temporarily drain the battery when they finish.
The more stuff you have on your iPhone, the longer the indexing process takes, so if you've just updated to iOS 16 and your battery is about to die, it's best to just wait. Depending on what's in your iPhone, this could take an hour or even a few days, but it will drain on its own and you'll be back to normal battery usage in no time.
Often, plugging your iPhone into a power outlet and charging it overnight while connected to Wi-Fi is enough to get it to work on its own.
2: Install app updates
Third-party apps can always increase battery usage, and keeping them updated is an easy way to ensure that such issues are resolved.
Open the App Store and then click on your Apple ID profile in the upper right corner, then scroll down to find the Updates section and install updates for any app or apps you use frequently.
3: Find out exactly which apps are using the battery.
Go to Settings - Battery and you will see a list of apps using the battery. This can provide information about app behavior, which apps may need updating, and what to do.