This paper presents a new vibration diagnostic method designed for diagnose of permanent magnets (PM) generators. Those machines are commonly used in small wind, water systems and electrical vehicles. The described method is very innovative and unique. Specific structural properties of machines excited by permanent magnets are used in this method - electromotive force (EMF) generated due to vibrations. In this article several issues will be discussed: the method genesis, the similarity of permanent magnet machines to vibration sensor, mathematical model, and results of simulation and laboratory tests. The method of determination the technical condition of PM electrical machine basing on its own signals is the subject of patent application [...