Influence of H2SO4 Concentration on Lead-Acid Battery Performance H-Type and P-Type Batteries

The present investigation determines the initial capacity performance and the changes in battery capacity on cycling of 12 V/32Ah batteries with six different electrolyte concentrations between 1.15 and 1.33 s.g. H2SO4. The batteries are cycled with two discharge currents, 3.2 and 8A. The utilization of PAM is 50% against 37% NAM utilization. The utilization of H2SO4 varies between 38 and 88%, depending on the concentration of H2SO4 in the electrolyte. At CH2SO4 = 1.24 g cm−3, ηH2SO4 ≈ ηPAM.when CH2SO4 1.24 g cm−3 (P-region) in which the lead dioxide plates limit the capacity of the battery (P-type batteries) At CH2SO4 1.24 s.g., the capacity of the battery is limited by PAM. It has been established that in the P-region of H2SO4 concentrations, the initial capacity of the battery is higher than the rated value (C0), but the life of the battery is short and require high charge voltages. In the H-region of H2SO4 concentrations, the initial capacity is lower than C0, but the cycle life is considerably longer than 100 cycles and depends on the discharge current and the H2SO4 concentration and allow to be charged at lower voltages. The voltage of charged cells on open circuit declines with decrease in H2SO4concentration, which allows charging of batteries at lower voltages, as is the case with IT batteries, and reversible sulfation of the plates is avoided as well. The obtained results of the present investigation suggest that lead-acid batteries can be divided in two types depending on the concentration of H2SO4 in them: H-type batteries with CH2SO4 1.24 s.g