how long does the charger case charge the AirPods

They have “Hey Siri!” capabilities, wireless charging, talk time went from 2 to 3 hours, Bluetooth 5.0, 2x faster switching between devices.

If the case is fully charged you can get over 24 hours use of the AirPods. 15 minutes of charging will give approximately 3 hours of use. A full charge will give 4-5 hours of use.