Cooling system for bus bars, in particular cell connectors or module connectors of batteries, comprising a bus bar with a first connection area for a pole of a first battery, a second connection area for a connection of an electrical component, an insulation encasing the bus bar between the connection areas, wherein the bus bar is free of the insulation at least in the two connection areas, characterized in that on a side facing away from the pole of at least one of the connection areas, a gel-shaped heat conducting agent is applied directly to the surface of the bus bar.