You can expect a 1% drop for every 25 cycles or about a 1% drop per month on average. If the phone was originally purchased new 9 months ago, then it is right on track and if it was purchased new longer than that, then you are doing better than average. The drop you experience will not be linear, meaning some months may not drop at all and other months will drop more.
After any iOS update there will be additional processes running in the background that will consume more battery power, produce more heat, and even appear to slow your device down. The same reports about battery draining quickly appear after every iOS update. The processes that are running are responsible for:
- Analyzing Significant Locations for Siri and Map Suggestions
- Analyzing all of your photos for objects to take advantage of the new algorithms
- Analyzing photos for memories suggestions
You will need to give your device at least 3 days to complete these background processes and your device should then return to normal. It will complete faster if the phone is left on and plugged in. If you still experience excessive battery usage after 3 days, then perform a Force Restart:
- Press Volume up
- Press Volume down
- Press and hold the side button until the Apple Logo appears. Ignore anything else you see on the screen during that time.
It may take a couple of attempts to get the speed and sequence of the key presses correct and the last step of holding the side button could take up to 15 seconds before the Apple logo appears.
