Comparing a Mobile Nature Guide and a Paper Guidebook in the Field

The cell-container, obtained by blow-forming, thus having a minor thickness, presents at the upper-rim a conformation in two steps (1) permitting the mating of the cell-lid to the cell-container remaining within unified overall-dimensions, as the welding-bead between the cell-lid and the cell-container forms itself on the inside instead of on the outside of the same. Furthermore, it becomes possible to increase the welding-surface according to one's need if the cell-container is cut in correspondence with the flat-part of the step. The cell-container presents, furthermore, horizontal-recessings at various levels permitting the modular-cutting of the product according to unified measures. The cell-lid's form is concave towards the exterior in order to follow the dilatations of the poles during the service-life of the battery. The cell-lid is also furnished with a molded ring, which has a circular profile around the electrolyte's inlet thus avoiding the application of a gasket onto the top-cover.