Valve-regulated lead-acid (VRLA) batteries with gelled electrolyte appeared as a niche market during the 1950s. During the 1970s, when glass-fiber felts became available as a further method to immobilize the electrol. Lead-acid batteries represent the oldest rechargeable battery system and despite their r. The lead-acid battery represents a rather complex electrochemical system of primary and secondary reactions. The discharging–charging reactions are based on the conversio. The VRLA battery is based on the same materials and electrode reactions as the conventional version. The main difference is the immobilization of the electrolyte and the internal oxyg. When the battery is overcharged, in principle, the same secondary reactions occur in the vented and the VRLA system, but their weighting is quite different.••. Discharge performance of VRLA batteries corresponds to that of the vented version, since the same reactions occur in both types. In general, discharge performance is degraded at lowe.
