iPhone 13 battery health dropped from 94% to 81% in 2 months

When was the last time that you replaced the battery at the Apple Store or authorized Apple service shop?

If you have never replaced the battery, it is probably failing and will need to be replaced. Make an appointment at the Apple Store / Genius Bar, or take the phone to an authorized Apple service shop. Do not choose an unauthorized repair shop, because they will not have access to a genuine Apple replacement battery.

You might be able to find a list of authorized locations in your area using this link: Find Locations

Good luck.

If the battery has never been replaced, it is likely failing. How long has it been since the phone was new, or had a battery replaced by Apple?