“…Although there are many failure modes of VRLA batteries, including premature capacity loss (PCL), grid corrosion, softening, sulfation, drying out, additive decomposition and poor separatorplate contact, etc., they vary with different designs, manufacturing and operating conditions [7][8][9][10][11][12][13][14][15]. In the deep cycle duty, the interface of the grid/active mass easily accumulates the lead sulfate crystals with very high resistance and forms a barrier layer when Pb-Sb alloys in the positive grid are substituted by Pb-Cd-Sn-Al alloys.…”