Via Jalopnik:

The patent filing, number 20090091138, describes several different designs which do away with the traditional generator design with a standalone power source driving a separate electromagnetic generator. In a traditional generator, an oscillating or rotating permanent magnet is driven externally and moves inside a tightly wound and carefully designed bundle of wires, creating a magnetic field which induces electrical current. This patent describes two different types of motors which utilize the normal oscillations of a piston engine as the permanent magnet to induce current in the windings wrapped around the cylinder or the connecting rod.