There may be many reasons for the data cable purchased online to charge quickly and slowly. The following are some possible reasons:
Data line quality problems: Some data lines may have quality problems, such as the poor quality of the metal conductor material inside the wire, poor line contact, etc., which will lead to unstable current transmission, thus affecting the charging speed.
Charger power mismatch: If the charger power you are using does not match the charging power of your phone or device, then the charging speed may also be affected. For example, if you are using a low-power charger to charge a device that requires a high-power charge, the charging speed will be slower.
Charging interface problems: There may be problems with the charging interface of the mobile phone or device, such as loose and dirty interfaces, which will affect the stability of current transmission, thus affecting the charging speed.
Charging ambient temperature: Too high or too low charging ambient temperature will also affect the charging speed. When charging in a high temperature environment, the battery temperature will rise, and the charging speed will be slowed down to protect the battery. When charging in a low temperature environment, the battery temperature will drop and the charging speed will be slower.
If you encounter this situation, you first check whether the charger, data cable and charging interface are normal, if these are not problems, then it may be the phone or the device itself. If the problem persists contact the seller or professional maintenance personnel for further inspection and repair.