When the battery is placed inside the coil and both magnets are touching the coil it produces a closed circuit between the two magnets, and current flows. As the current flows through the conductive copper wire a magnetic field is created around the wire. This magnetic field interacts with the magnetic field created by the neodymium magnets in a way that repels the magnets on one end, and attracts the magnet on the other pushing the battery through the coil.
As the train moves, the process repeats in the section of the track between the two magnets, making it run until the battery has no juice left! The coiled bare copper wire acts as the conductor. It is important that the wire is bare (not enameled) and is coiled as tightly as possible only just wider than the diameter of the magnets being used, which in turn should be the same diameter or slightly larger than the battery being used. Next, you need to take your battery and add a magnet on each end. Follow the next steps of this project to make this simple electromagnetic train.