Frequently Asked Battery Questions
Q: What is a contract battery?
A: A contract battery was manufactured as a new part for Pontiacs. All batteries installed in vehicles at Pontiac assembly plants were considered "contract" batteries. Delco-Remy, even though it was a division of General Motors, was required to bid for the contracts to supply batteries to assembly plants. Thus, to keep its costs down, Delco-Remy never painted contract batteries.
Q: What is a counter battery?
A: A counter battery was manufactured for sale at Pontiac dealership service counters and at Delco-Remy retailers.
Q: Is there a difference in internal design between contract and counter batteries?
A: No.
Q: Do contract and counter batteries appear the same?
A: No. A contract battery was never letter-painted. A counter battery was letter-painted by Delco-Remy before being shipped to a dealer for retail sale.
Q: What is a tar-top battery?
A: The tar-top battery earned its name from the tar that was used to seal the six individual top covers. Tar-top batteries were used at Pontiac through 1966, in most applications.
Q: What is a lead-acid battery?
A: A lead-acid unit utilizes electrodes of lead metal and lead oxide in an electrolyte of sulfuric acid to store voltage. It's the design used by Delco-Remy in most of its Pontiac applications through 1975. Lead-acid batteries may sometimes spew acid out of the vent caps if they're overfilled or overcharged. This acid can corrode battery cables, battery hold-downs, battery boxes and discolor the paint on vent caps.
Q: What's inside a lead-acid battery?
A: Each 12-volt battery case is divided into six cells by walls called partitions. Each cell contains separators. (The number of separators varies by the amount of lead plates per cell.) Each of the separators has lead plates attached. The lead plates of each cell are joined to one another by "connectors." More lead plates per cell means more cranking power for the battery.
Q: Why are vent caps used in lead-acid batteries?
A: To let the pressure out of the case because gases will build up as the battery charges and discharges due to the electrolytes (acid). Vent caps can also be removed to check water levels and to check specific gravity with a hydrometer.
Q: What does a battery group number mean?
A: A battery group number is an industry-standard specification for batteries, defined and regulated by the Battery Council International (BCI), formerly called The Association of American Battery Manufacturers (AABM). The purpose of BCI is to set up guidelines the battery manufacturers adhere to. All '55 through '69 Pontiacs (excluding 4-cylinder '61-'63 Tempests) used a Group 24 battery, which measures 101/4 inches long by 63/4 inches wide and 9 inches high to the top of the post. All Group 24 batteries are top post. In 1970, Delco-Remy introduced the Group 74 side terminal battery at 101/4 inches long, 7 inches wide and 83/4 inches high (to the top cover). In the Pontiac line, it was first installed in cars equipped with the 455 engine.
Q: Why is my battery imprinted with "459" when the battery model number is really 458?
A: Delco-Remy used the same battery cases to make both the "wet" and "dry" batteries, and to save money. Your Pontiac shipped with a wet battery and Pontiac service parts dealers sold dry batteries. Example: 459 or 559 (odd numbers) signify the dry model on the front and 458 or 558 (even numbers) signify the wet model stamped into the top.
Q: What is the difference between a wet and dry battery?
A: A wet battery is delivered fully operational with electrolytes added. Conversely, a dry battery is purchased requiring four quarts of electrolytes and charging before it's ready for use. Water is then added as needed to maintain the correct electrolyte level.
Q: I found an NOS Delco-Remy battery online. Is it valuable?
A: Probably not, for three reasons. First, the NOS batteries remaining in the hobby are counter batteries and don't correctly match the black contract battery and date-code that shipped in your Pontiac when it left the factory. Secondly, NOS batteries decay over time and do not hold a charge properly. Third, NOS counter batteries have a warranty "punch-out" decal that was never applied to your original battery.
Q: Is a reproduction battery a better choice than an NOS battery?
A: Absolutely! Reproduction Delco-Remy batteries from the supplier we contacted are correct in appearance to the battery that was supplied in your new Pontiac. They also use current technology to maintain long life, and sufficient cranking amps to start your classic Pontiac without worry.
Conclusion
Next month, Delco-Remy enters the musclecar era with the famous Delco Energizer R59, the side-terminal R79/R89 and the torque-taming R89W. Plus, Pontiac's very first maintenance-free battery, a commentary from Pontiac historian John Sawruk on POCI judging of your battery, and more.