A review of soft-lead specifications in the light of the requirements of valve-regulated lead/acid batteries

With the development of valve-regulated lead/acid (VRLA) technology and its concomitant requirements in terms of the quality of the input materials, there is a need to review the status of the present pure-lead specifications as they appear in the majority of national standards for lead. In this paper, four national standards for soft lead are compared with a list of elements that have been identified and reported in the literature as being harmful to the VRLA battery system at impurity levels. None of the four standards is found to limit the presence of all harmful impurities. An alternative specification that meets the needs of VRLA technology as they are currently understood has been proposed.