In this paper, a prototype of a regenerative hydraulic suspension is constructed, modeled and produced. The regenerative device theoretically and practically enables the storage of a part of the vehicle vibration energy. The proposed regenerative suspension, in relation to previously published research, enables permanent storage of energy in the hydraulic accumulator and is designed for approximately real dynamic loads that occur when driving a vehicle. A prototype design methodology is proposed and contains a calculation of all critical components of the device which are important for the mechanical functionality of the system. A novel nonlinear dynamic numerical bond graph model of a regenerative hydraulic suspension with two degrees of freedom is proposed. The presented model contains and combines different physical effects, which some of them were not taken into account in previous research (e.g. weights of all significant components, approximations of all local and longitudinal hydraulic energy losses, stiffness and damping of vehicle tire, hydraulic stiffness of oil in cylinder chambers...). By simulating and analyzing a numerical model of a regenerative system with two degrees of freedom, different approximate dependences were obtained on how a some parameter change affects the values of regenerated power and driving comfort (relative displacements). In particular, the impact of changing the following parameters were analyzed and investigated: road quality, amplitude and frequency of input excitation, vehicle tire stiffness and damping, unsprung and sprung vehicle mass, suspension spring stiffness, hydraulic cylinder diameter and gas volume / precharge pressure in the hydraulic accumulator. After the research, it was discovered that the greatest influence on the regenerative potential of such devices have the amplitude and frequency of the input excitation, the stiffness and damping of the vehicle tire and the diameter of the hydraulic cylinder of the proposed device. The conclusions of this analysis generally agree with the conclusions set in previously published research. Simulation of the bond graph model of a regenerative system with two degrees of freedom (for differently set parameters) most often yields values of useful regenerated power between 10 and 100 W. The novel results of this work and the results of previous research of regenerative suspensions show good agreement (same order of value). The final proof of the basic hypothesis of the work was confirmed experimentally on a actual prototype but also with an approximate simulation of the experiment where the average (mechanical) regenerated power of 5.2 W and maximum regenerated power of 11.5 W was obtained. These regenerative power values are comparable to the power values which have been published in other research papers. The simulation results and the experimental results in this paper approximately agree although there are some small disagreements that represent space for future research in this scientific field.