FAQs from Samsung (My device is charging slowly) Check your charger.
Although most phone chargers and charging cables look similar, there can be a huge difference between their quality and charging speed. It is always recommended to use the charger that came in the box or an official Samsung replacement as these have been specially made for your device.
If you're using an official charger, check to ensure that there isn't any damage to the cable or plug. If you notice any damage, stop using the charger immediately. While checking your charger, look at the charging port on your device to ensure that it is free from any debris.