If your earbud is not fully charging, please follow the below steps.
1. First charge the earbud continuously for more than 4 hours, and check if the problem has resolved.
2. Use a different standard adapter and cable for charging.
3. Charge the earbuds and charging case in an environment where the temperature is between 0°C and 45°C for optimum charging. If the temperature is too low or too high, it may be difficult to charge the earbuds and charging case
If the above troubleshooting doesn't work, please get in touch with Nothing Customer Service for further help.