This is a normal phenomenon. The general charger will generate heat when charging, but some of the heat is larger. Some produce less heat. The size of the heat depends on the design problem, the capacity of the charger considered by the famous brand manufacturer is relatively large, and the quality of the material used is also guaranteed, so the heat of the charger of the famous brand manufacturer will be relatively small.
The quality of the charger produced by a small factory is poor, and the heat will be larger, which is mainly due to cost considerations.