Cells VRLA cylindrical

A listing of VRLA cylindrical batteries is given in Table 24.2. The performance of these units at various current drains at 25°C is given in Fig. 24.47. A number of multicell batteries are available that use these cells in various series/parallel configurations. 

In recent years the market for small, portable lead-acid batteries has grown considerably. Almost all portable batteries are VRLA designs. Both cylindrical and rectangular (prismatic) unit cells are made and assembled into multicell packs. 

Conventional polypropylene is an appropriate container material for cylindrical VRLA cells because the necessary contact force for the glass-mat separator is supplied by the winding and maintained by a tensile force in the cell wall. Regardless of the nominal voltage, and therefore the number of cells, prismatic VRLA batteries require a reinforced plastic for the container and the lid to provide an AGM contact force and to keep the active-material compressed [42-44]. 

Figure 15.12 Principle of a cylindrical VRLA cell (Design of Gates, United States).

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