A system for the storage of electrical energy for a vehicle with electric propulsion; the storage system presents: at least one group of chemical batteries, which are arranged aligned with one another and each of which presents an upper wall, which is provided with a pair of electrical terminals and with a safety valve, and a lower wall, which is parallel and opposite to the upper wall; a container, which houses the group of chemical batteries; a relief duct, which rests against the upper walls of the chemical batteries and presents, for each safety valve, a corresponding opening, which is coupled to the safety valve; and a cooling element, which is parallel and opposite to the relief duct and rests against the lower walls of the chemical batteries.