Potential energy of an implement and implement supporting member, such as a mechanical arm, attached to a machine, such as construction equipment, is recovered by an energy converter, such as a generator or a motor driven by a flywheel or a pull-cord generator, during relative movement between the implement supporting member and the machine. An activator causes relative movement between the implement and the machine. The flywheel or pull-cord generator drives an auxiliary pump or electric generator when the flywheel or pull-cord generator moves relative the auxiliary pump or electric generator. The recovered potential energy is stored in an accumulator or battery. Kinetic energy may be converted to electric energy or hydraulic pressure and stored for later use.