While in use, a solid green light indicates the Wonderbook is in play mode. A flashing green light indicates the Wonderbook is in pause mode. A flashing red light indicates a low battery and less than one hour of play time left. It should be charged at this time. When charging, you will see a flashing green light and solid red light. The red light will turn off once fully charged. Wonderbook charges completely (from dead to full battery) in one hour.