1. Make sure that the headphones are correctly positioned in the charging case.
2. Make sure that the battery of the charging case is not discharged. Charge the case if necessary.
3. Make sure that the charging contacts of the headphones and the case are clean and firmly in contact with each other.
4. If the headphones or the case have been exposed to low or high temperatures for some time, wait until the temperature of the device equals room temperature, and only then try to charge them
We recommend using a power adapter with the following characteristics: 5V, 0.5 A. When using a more powerful charger, the probability of a malfunction of the charging case increases.