Prest-O-Lite Factory Marks
Indianapolis—50 Cleveland—7 San Francisco—23
For example: “50-K” indicates that the battery was manufactured at Indianopolis in January, 1920.
In addition to the above, each “Wet” Prest-O-Lite battery is branded in the side with a date, as “9-19,” indicating October, 1919. This date is really sixty days ahead of the actual building date, to allow time for shipping, etc., before the guarentee starts. The branded “9-19” was actually built in August, 1919.