Hybrid vehicles require an energy storage device capable of delivering or absorbing high specific powers (powers per unit of the device size), and still, in some cases, adequate levels ofspecific energy. The paper shows that high power Lithium Batteries already on the market are able to fulfil this task satisfactorily, by means of experimental tests, whose results are shown and discussed. The results show that very high power lithium batteries can be used in hybrid vehicles as the sole energy storage device, thus avoiding the complexity of composite (e.g. battery plus supercapacitor) storage systems.