This undated notebook was probably used by Edison during the period 1913-1914; several of the entries were annotated in June 1926. All of the entries and notations are by Edison and pertain to the construction, electrical capacity, and efficiency of his alkaline storage batteries. Most of the entries contain data and observations, probably transcribed from earlier notebooks, regarding numbered cells made with experimental iron "pockets" or negative electrodes. Also included are notes, probably transcribed from earlier notebooks, pertaining to experiments made with various electrolyte solutions and positive electrode "tubes" and to tests made under different charge and discharge conditions. Among the earlier notebooks consulted are N-06-09-05, N-10-02-24, and N-10-10-31. The notations from 1926 consist of brief observations about specific data, along with disparaging remarks about former employee Dr. Otto Grothe. The front cover is labeled "Very Important." The pages are unnumbered. Approximately 50 pages have been used.