Delco-Remy 2SM50 Battery
In 1955, Pontiac used Delco model 2SM50. It was the first Delco Group 24 12-volt battery that employed a hard rubber case, though it still used wooden separators to divide the lead plates. The separators were made from either cedar or Douglas fir, and lead straps over the partitions connected the cells (connectors). It was the last year for wooden separators and for the black Delco vent caps with the yellow ring.
Physical Features 2SM50 battery • GM Part No. 1890488 • 1955 only
2SM50 is stamped on the upper edge, but this model number isn't visible when the battery is installed in the car. The GM Part No. doesn't appear anywhere on the battery. The upper flat area reads (in an indentation) "50AMP-HR." The center area reads "DELCO" in large letters on a stippled background. One-third of the bottom area is flat and reads "DELCO-REMY. ANDERSON, INDIANA.MADE IN USA . GENUINE HARD RUBBER." The left side also has a smooth indentation with the words "DELCO-REMY. ANDERSON,INDIANA. MADE IN USA."Delco-Remy 2SMR53 Battery
For 1956, Delco-Remy introduced the 2SMR53. This 53-amp HR battery used both the hard rubber case and hard rubber separators. The latter were thinner than the wood separators, which allowed more active plate material and thus a higher battery capacity. Vent caps were changed to a solid yellow with "DELCO" in large letters.
Physical Features 2SMR53 • GM Part No. 1890587
1956-1957 The model number was again stamped on the upper lip, but also isn't visible when the battery is installed in the car. The upper flat area reads (in an indentation) "2SMR53." The center area is stippled, except fora large smooth area that reads "DELCO ORIGINAL EQUIPMENT LINE." Above the "flat" area (in the stippling) reads "RUBBER SEPARATORS - HARD RUBBER CASE." Below the "flat" area (in the stippling) reads "A GENERAL MOTORS PRODUCT." The left side also has a smooth indentation with the words "DELCO-REMY. ANDERSON,INDIANA. MADE IN USA."