Abstract: An electric battery pack is manufactured by a process whereby an outer insulating casing has contact strips partly inserted through apertures in opposed sides thereof adjacent a closed bottom thereof. A series arrangement of connected batteries is inserted into the casing until the positive and negative poles of the series arrangement engage against the contact strips. A cover having integral inward projections is pressed towards and against the casing to close an open end thereof, the inward projections being stressed and deforming against end batteries to secure all the batteries immovably in position, and the cover being welded to the casing. The inner ends of the contact strips are then welded or soldered to the poles of the series arrangement from outside the casing through access orifices in the closed bottom of the casing.