After delivery to a lead-acid battery manufacturer, the separator roll is fed to a machine that forms “envelopes” by cutting the separator material and sealing its edges as shown in Figure 3. Next, either a positive or negative grid that is pasted with electrochemically active material is inserted into the envelope to form an electrode package. The electrode package is then alternated with the other grid type to form a stack in which the separator acts as a physical spacer and an electronic insulator between the grids (i.e., electrodes). After making series and parallel connections between the grids, sulfuric acid is then introduced into the assembled battery to facilitate ionic conduction. The battery then goes through an electrochemical formation step prior to final inspection and shipment.