This is most likely due to using a non-fast charging wall plug. Please make sure you are using a quick charge plug or at least a wall plug that can support 2.4A wall plug. For example, standard Apple wall plugs are not powerful enough as they only support 5V 1A. If you are not sure, please have a look at our Qualcomm Quick Charge 3.0 Wall plugs, this way you will be guaranteed to get the full fast wireless charging speeds. You can find them here.