If the Xiaomi Robot Vacuum S40 cannot charge properly, please refer to the following steps to troubleshoot:
1. When used in high or low-temperature environments, the robot vacuum will automatically reduce the charging speed to extend the battery life, which is a normal phenomenon;
2. Please check if there is dust on the charging port or contacts of the robot vacuum. Wipe them clean and try again;
3. Make sure there is enough space around the charging dock; otherwise, the robot vacuum cannot dock onto it for charging;
4. Ensure that the robot vacuum is properly aligned on the station.
If the above steps cannot resolve the issue, please contact the local after-sales service center for further assistance.