On many modern vehicles, the battery is not just a part in a box. The car's computer monitors it and adjusts how hard it charges. When you install a new battery, the computer needs to know about it. This is called battery registration, or coding.
The car's charging system is tuned to the battery's age and capacity. If the car still thinks it has the old battery, it can overcharge or undercharge the new one, shortening its life. Start-stop and other features may also not work properly.
It is most common on European makes such as BMW, Mercedes-Benz, Audi, Volkswagen and Volvo, but a growing number of vehicles from other makers have battery sensors and start-stop systems that expect it. The specifics vary by model and year.
If you are replacing the battery yourself on one of these cars, you may skip the registration step without knowing and cut the battery's life short. When you book a replacement, tell us the make, model and year, and ask what your car needs.
Use the finder to see which battery your car takes, or call for a test.
Pick your vehicle. 21 makes, 149 models, 1990 to 2026. We show the battery group size our technicians will bring.
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The honest answer: it depends on climate, driving habits and the battery itself.
We come to you, test the battery and tell you straight.