In previous paper [1], a bi-directional energy conversion system has been developed and described to drive an electric scooter, as well as to recover braking energy using supercapacitors as unitary energy/power source. Two test conditions are verified with reasonably-well correlated results published. However, there were a few problems and ambiguity presented in that paper. First of all, influences due to road load change was not carried out, so that the circuit was not tested up to its fuller operational range where potential issues may occur.Secondly, the DC-DC converter, used to boost the motor back EMF to a higher DC bus rail voltage, was treated as a “black-box” type component with its input and output variables unevaluated. This, suspectedly leads to a “tailing effect” observed in [1] which was not explained and couldn’t be understood well without further characterization of the DC-DC converter alone. Lastly, a lot of noise due to EMI was present in some measurement channels that needs to be mitigated so as to give more meaningful and accurate data.All issues aforementioned tie themselves to the test platform of the original paper [1] – the road test conducted in an open area has too many constraints that important variables cannot be easily adjusted and calibrated. In other words,variables subject to test environment such as human weight,ramp angle, ground defects, even wind and traffic conditions are often uncontrollable. Measurement instrumentation was limited due to cramped package space. Even worse, thermal runaway may occur under high load conditions which will eventually lead to transistor damage on the board without driver’s notice.The solution is to, instead of road test, build and use a dedicated test rig, with the abilities to adjust load and other parameters, while keeping the chassis of the scooter stationary.The structure of this paper is arranged such that in section II, the operating principles of the scooter sub-system in [1] is recapped briefly; section III focuses on detailed design of the test rig sub-system including implementing a four-quadrant variable speed drive(VSD); finally, three cases of operating conditions are designed in section IV, evaluated rigorously in section V, with comprehensive experimental results shown,discussed and conclusions drawn in section VI.