This notebook covers the period October-December 1904. It contains notes and drawings by Edison regarding storage batteries. Included is a twenty-nine-item list entitled "Experiments on Battery for ESBCo," followed by observations drawn from the results of endurance tests performed at the Silver Lake plant and from the examination of cells used in a Studebaker electric vehicle. Also included are entries regarding defects in the batteries and outlining possible causes for the loss of cell capacity. Inserted into the book are several pages of notes by Edison and an unidentified experimenter concerning the battery tests. The front cover is marked "T.A.E. Observations & Theories." The pages are unnumbered. Approximately 80 pages have been used.