"Coil magnet battery". That's what I googled to re-find this video that I saw on Facebook last week. At first sight it looks somewhat strange but when you start to think about it it's quite understandable. The wire is un-insulated copper and the magnets are attached to the end of a battery. The magnets make contact with the coils causing current to flow. The coils are in the magnetic field of the magnets resulting in a force (Flemings LHR). The magnet then experiences an equal and opposite force (Newton 3) that propels it along the coil. The thing I don't get is why I have never seen this before.

Great potential for an EE here.