Development of advanced electrolyte retainers for improvement of the life cycle of valve-regulated lead-acid batteries

Advanced electrolyte retainers have been developed to improve the life cycl e of valve-regulated lead-acid (VRLA) batteries. One of the retainers is a separator mat which contains synthetic wood pulp (SWP), or fine polymer fib re. It shrinks less than conventional absorptive glass mat (AGM) when wette d with acid and is so elastic that the plates are kept well-pressed togethe r when the volume of the plates changes during charge and discharge. The ot her retainer is granular silica which fills the space between and around th e plates instead of the AGM. In a battery using this type of retainer, the plates are tightly compressed from all directions and the compression does not decrease after water loss. The basic characteristics of these new retai ners and their influence on battery performance are discussed. (C) 1999 Els evier Science S.A. All rights reserved.