|1. The charging current of power bank or laptop is not enough to charge the ring 2. If the ring is not used for a long time, the battery will be depleted severely. It will take 3-5 minutes to initiate charging before the green light flashes, indicating that the charging is in progress 3. Try reconnect the ring and the charging connector, or the charging electrode may be oxidized, try to clean the charging electrode of the ring with an alcohol cotton ball and then charge again 4. Change another power adapters to charge the ring 5. Insert the power adapter in another 220v AC socket to try again.