This study focuses on energy harvesting from vehicle suspension by employing a regenerative rotational shock absorber. Designing, manufacturing and testing of a prototype device is done step by step to provide a useful manual for researchers. The prototype damper was especially designed for low frequency applications. A rack-pinion mechanism was proposed to transform linear motion to rotational one. Unidirectional motion was realized by using a new combination of bearings and gear chain mechanism. This mechanical rectifier was coupled to light weight gear box with high reduction factor. Experimental studies were conducted in laboratory by utilizing a damper testing device. Excitation vibration motion on prototype was in constant amplitude (25 mm) and at variable low frequencies (0.16, 0.32 and 0.48 Hz). Additionally, different resistances were tested as an external load for electric generator (0.66 similar to 10.4 omega). Generated voltage and power in different case studies were presented. The maximum power was found to be 35 W and the maximum performance achieved was 34.36%. The range of calculated damping coefficient is in between 4800 Ns/m and 16000 Ns/m that is convenient for passenger and commercial vehicles.