This folder contains documents pertaining to primary (non-rechargeable) batteries. The five selected items for 1918 are technical notes by Edison, addressed to experimenter Harold N. Cox at the "Primary Battery Co." (probably the recently established Edison Primary Batteries, Inc.) The notes relate to experiments with graphite coating and to battery electrolyte saturated with zinc oxide.

All of the documents have been selected except for one unsolicited inquiry about shares for sale, marked "no answer."