Two series of duplicate batteries were made. One series had a dense positive paste and the other series had a more voluminous positive paste. Identical negative plates were used with all of the batteries. These batteries were tested by ten different commercial battery manufacturers and their results were submitted for this final tabulation. Some battery tests were made according to standard specifications of the Society of Automobile Engineers. Other tests included the “E” or “Razzle Dazzle” test, besides a number of non‐standardized laboratory tests. It was found that no two laboratories, using the same testing procedure, obtained the same results. Some of these life tests did not show any appreciable difference, even though the individual batteries differed widely. However, most of the tests show certain distinct differences between widely different batteries.