Abstract: A device, configured as a double mold, for casting terminal bars (straps) and terminal poles onto the lugs of a completely assembled plate group for electric storage batteries ensures optimum attachment of all of the lugs (both polarities) to the molten bar lead if the heat exchange between the bar lead and the dipped volume of each negative or positive lug is identical. This requirement is met by causing the negative and positive casting molds, together with their contents, to form thermally equivalent sections or blocks, which are equalized if necessary, by changing the dimensions (thickness) of the mold's walls. When the lugs are made of lead or a lead alloy, such a double mold also makes it possible, during a subsequent two-stage cooling process, to first allow the terminal poles to solidify, simultaneously, and to then allow the terminal bars to solidify, simultaneously.