Check that no other objects are between the holder and the phone.Make sure the holder doesn't get too hot. If the holder is too warm, take your phone from the holder, and unplug the power supply. The holder may switch off automatically if it is too hot. This may happen if you are doing many power hungry activities at the same time e.g. talking on the phone and navigating at the same time. When the holder has cooled down, try charging again.