Assembly and performance of hybrid-VRLA cells and batteries

Several commercial-grade hybrid-VRLA and AGM-VRLA cells and batteries have been assembled and tested under varying charge–discharge rates in a temperature range between 50 and −40 °C. Impedance studies on hybrid-VRLA and AGM-VRLA cells have been conducted to reflect on their resistive and capacitive values. A linear relationship is found to exist between logarithmic state-of-charge values and ohmic impedance of batteries. In general, hybrid-VRLA cells and batteries perform better than their AGM-VRLA counterpart. A field-performance study conducted on AGM-VRLA and hybrid-VRLA batteries for solar-lighting application also suggests the latter to be superior.