The electric vehicles are considered one of the most fast-growing industries today. Their efficiency exceeds the efficiency of internal combustion engines, but it can be improved even more. The power supply - Li-Ion accumulator - provides significant heat losses due to its internal resistance. Connecting supercapacitors in-parallel to the accumulator battery can decrease these losses. This paper shows that efficiency of such connection depends on the supercapacitor capacitance and the rational value of capacitance, providing minimum energy consumption, exists. During the study the modernized system of power supply distribution for pause recharging of supercapacitors has been proposed. This system provides additional energy economy without implementing different components to the electric drive. The study shows that the tendency of increasing the efficiency of electric vehicle drives works for high-voltage power supply as well as for low voltage ones with the implementation of a DC-DC voltage converter.