A system for the supply of electrical energy by means of one or more high-power electrochemical cells. The system comprises a housing, such cell or cells being located at least partially in said housing and a fan or fans actuated during heavy discharge of the cell or cells to prevent the temperature rise of the cell or cells above a certain value. The system is of importance for high power cells, such as the various types of lithium cells, calcium, lithium alloy and calcium alloy cells. Temperature sensing means and a switch can be provided adapted to actuate the fan or fans when the temperature exceeds a certain value so as to provide cooling forced air circulation.
