The Magcell unit has three LED's on the face. Before downloading you need to make sure the green light is on, indicating the unit is ready. Place the baton on the unit and you will see the middle light light up. When the middle light flashes take the baton off. If the bottom light flashes this indicated the upload was unsuccessful and needs to be redone, this could also mean the baton is empty.
Below are two small video clips showing potential problems and the correct way to do it.