This document is especially interesting when looking at the time frame of the publication's release which is about two months after the release of the Civil Aeronautics Board's Aircraft Accident Report for UAL flight 823.
This FAA order mentions an article written by Lewis Hofstatter, an engineer for the Sonotone Corporation. (The article in its entirety follows in next section). The FAA mentions that Sonotone conducted tests on its batteries in desert conditions. No date for these tests was given.