https://wccftech.com/airpods-get-optimized-charging-support-with-ios-14/

Apple has added support for optimized charging for AirPods in iOS 14. This feature aims to prolong AirPods battery life by slowing down charging once it goes past 80%. Apple had first introduced optimized charging in iPhones, and recently added it to the Mac.

Hüseyin İyibaş on Twitter shared a screenshot of a notification on his iPhone running iOS 14, which shows the following message: