Failure mechanisms of lead/acid automotive batteries in service in the U.S.A

Discarded lead/acid batteries were selected at random without regard to brand or condition and these were inspected and tested to determine the causes of failure. Samples were limited to 12-V automotive passenger-car batteries. Their age was determined from the manufacturing code and shipping date. In addition to the cause of failure, information on battery components and construction was also noted. Data are presented showing the principal modes of failure, the effect of geographical location, and the influence of grid alloy on life. In particular, the differences observed between those batteries utilizing calcium alloy for the positive grids and those using antimony alloy are discussed.