Understanding Car Battery Date Codes

by Phil Borges // in Car

Many people forget to consider the date code on the battery when buying a car. It gives information about the dates on car batteries, such as the car battery manufacture date and how soon it will last its service. However, most car owners are confused about what it means or clueless if those numerical or alphabet codes have meaning. This article will clearly explain the car battery codes and why they are essential to understand before purchasing.

Battery Date Code Chart










D = Day of Month (02 = 2nd)





M = Month (A-L > E = May)





MM = Month (07 = July)



Back Side


MMM = Month (Oct = October)





Y = Year (14 = 2014)



P = Production Line





S = Shift



Back Side


F = Factory






Back Side


What are these Battery Date Codes?

Mostly, car batteries have different types of battery options with stamped date codes to show how old the battery is. These codes indicate the month and year of manufacture, allowing you to determine its shelf life. For example, the “D” in a code means that the battery was made in December 2018; subtracting it from the current year and month yields your battery’s age.

Do you think knowing the battery age is something that has any value at all?

Yes. Knowing the battery age helps you to know if a car won’t charge long enough or will stop working altogether. This way, you’d know if the battery reaches the end of its life cycle; thus, it needs to be replaced as soon as possible. Typically, the average lifespan of a car battery is 3-5 years. When the battery reaches the end of its life cycle, it will have to be replaced with a new one. Therefore, it is important to know how to read battery date codes.

Is there an easy way to check and see when the car battery was manufactured?

Yes. The first number tells you the year of manufacture, while the second number indicates the month. So, a battery stamped with “D34” was made in December 2014. The last two digits are to be ignored. You’ll see this when you purchase your new battery, with months indicated before their “in service” date.

Common Battery Brands with Battery Date Code

1. Napa battery date code: it is a 1-4 digit numeric code with the first digit indicating the year and the following three numbers, or letter in one case, denoting the month of manufacture. For example, “M53” means April of 2013.

2. Deka battery date code: it is a 2-digit numeric code with the first digit indicating the year and the second digit indicating the month of manufacture. For example, “05” indicates May 2005 or 25% (the reciprocal) of 5 years from the date of manufacture.

3. Interstate battery date code: it is a 1-3 digit numeric code with the first digit indicating the year and the next two or three digits denoting the month of manufacture. For example, “D35” means December of 2015.

Moreover, the Interstate Battery company uses three possible date codes, depending on the length of their battery. These are the following:

  • A. The five or four-character code is in either SSMDY (January to September) or SSMY (October to December). The number and letter combinations represent a month followed by two digits for days within that year’s calendar. For example, “0613” represents June 13th, 2013.
  • B. The battery’s top is engraved with five numbers that signify the month and year of its production. The first two digits are an easy way to tell if a battery is safe for use or expired.
  • C. Every battery has a five-character sticker in the top left corner of the casing. The first two numbers on this label correspond to the month and year it was manufactured, just like your car’s Vehicle Identification Number (VIN). The stickers beneath every electronic device or toy you own have strange things about them, like how they’re hidden from sight until you take apart devices for recycling purposes.

4. AC Delco batteries date code: it is a 1-2 digit numeric code with the first digit indicating the year and the second showing the month of manufacture. For example, “D45” means December of 2014.

Final Thoughts

Different brands of batteries have different codes, too. So, knowing which one applies to your car’s battery is essential. Knowing these date codes helps you to assess the car batteries’ lifespan, which is vital for safety reasons. Identifying a faulty battery can help you avoid an unfortunate accident or having your vehicle break down on the road by taking an immediate battery replacement.

About the author, Phil Borges

Phil Borges is a battery aficionado. He's written extensively about batteries, and he loves nothing more than discussing the latest innovations in the industry. He has a deep understanding of how batteries work, and he's always on the lookout for new ways to improve their performance.