Charge the Lily Digital Pen by plugging a Micro-USB Cable into the charging port at the back of the Lily Digital Pen. Plug the other end of the cable into your computer’s USB port or an available USB charging adapter. After the battery is fully charged, the battery indicator will turn green. A red battery indicator means it’s time to charge the Lily Digital Pen. Note: If the Lily Digital Pen is completely drained, it takes approximately 90 minutes to fully charge the battery. A full charge will last for approximately 80 minutes of continuous use.