If it is burnt, it is mostly a line problem, check the connection between the charging port and the battery box, and the battery box.
< br >
If it is sour or rotten egg smell, it is most likely to be charged, open the battery box to see if the battery is deformed.
< br >
If the Bluetooth speaker voltage is the same. The charger can be universal, it is best to know whether the output of the commonly used charger is the same.