This paper deals with a Lyapunov based control principle in a hybrid energy storage system for electric vehicle. The storage system consists on fuel cell (FC) as a main power source and a supercapacitor (SC) as an auxiliary power source. The power stage of energy conversion consists on a boost converter connected with the main source and a buck-boost converter connected with the auxiliary source. The converters share the same dc bus which is connected to the traction motor through an inverter. The aim is controlling power converters in order to satisfy the following requirements: i) tight dc bus voltage regulations, ii) perfect tracking of SC current to its reference, and iii) asymptotic stability of the closed loop system. It is clearly shown, using formal analysis and simulations that the designed controller meets all the objectives.