Charge only the charging cradle

To charge only the charging cradle, charge without putting in the earphones.
1.
Use the included USB charging cord to connect the charging cradle to a separately sold USB PD supported AC adapter (USB Type-C).
The charging cradle status indicator LED flashes (red, yellow, or green), and charging starts.
Charging is complete when the charging cradle status indicator LED turns off.
Charging time (the time from empty to full charge)
Charging only the charging cradle
About 2.5 hours