Hi, there could be a few reasons to cause slow charging. Obviously if your using it while charging it will slow it down that’s one. If the battery is getting old that can also cause it. The main one is the charging outlet or plug. The more AMP the faster the charge. For instance a 5v 2.1 A will charge slower than 5v 3.1 A . Now if your using the same plug and everything as you always have it’s probably the battery. Or finally it could be something running in the background on your device a background process. Try using a different USB plug or charging the phone while it’s completely turned off see if that helps.