An apparatus for operating as DC motor and DC generator is provided. Two permanent magnets are placed to be able to rotate with a shaft and one coil is placed outside the circumference of the permanent magnets and one device for making electric current flow in the coil is placed. Two secondary cell batteries are used to supply electric current to the coil. The secondary cell batteries are charged by using back-emf which occurs in the coil. If the shaft rotates without using the secondary cell batteries, the secondary cell batteries are charged by the rotating permanent magnets.