It takes about 1.5 hours to fully charge your Ultrathin Keyboard Folio Type-S.
To charge the keyboard:
Locate the micro USB cable that came with your keyboard.
Insert the micro USB connector into the port on the keyboard.
Plug the larger USB plug into either a PC or your USB charging adapter.
The power and battery status LED will:
Blink green while the keyboard is charging
Turn solid green when your keyboard is fully charged
For battery information, see answer 360023422353.