When the MimioTeach is running on battery power, the stylus will not charge. Please plug the Teach directly into the computer with the USB cable or use the provided USB adapter to plug into the wall and the stylus will charge. If the stylus still does not show a green LED, try rotating the stylus 360 degrees while in the holder to see if contact is being made with the charge pin. Also, try cleaning the contacts on the MimioTeach with a micro-fiber cloth to ensure that nothing is interfering with the charger contacts. If no green LED is shown while rotating the stylus, please contact Technical Support. We recommend charging the stylus overnight before using it for the first time and when not in use for maximum performance.