Car Battery Sizes – Does It Matter?

It should come as no surprise that car batteries not only come in all shapes and sizes, but also in various electrical capacities. This makes sense because the wide variety of vehicle sizes and types in use make it unlikely that a single battery can serve every application. But does car battery size matter? And what if you are wondering what size battery for my car is best? Let’s take a look at why car batteries are different sizes and what car battery sizes you might find under the hood of most cars, trucks, SUVs and vans.

Why Are Car Batteries Different Sizes?

The very earliest cars used batteries of various sizes with no standards whatsoever. Battery manufacturers simply made batteries the way they wanted and car makers picked whatever fit. But then the Battery Council International (BCI) was formed and battery sizes started to fall in line with the standards set forth by the BCI. This helped simplify and standardize automotive engineering designs with common battery tray sizes as well as power output measurements.

Common Car Battery Sizes

Over the years car manufacturers figured out it was easier to just stick to a few common battery sizes to use across their production lines. The car battery size chart below lists out the dimensions of the most common car battery sizes:

That may look like a long list of car battery sizes, but there are actually many more in use around the world. A more inclusive battery size chart for cars, trucks, SUVs and other vehicles can be found in the NAPA Batteries Application Guide here.

Size Isn’t The Only Factor

Looking at the above car battery sizes chart you may notice that some batteries are physically the same size, but that doesn’t mean they are interchangeable. The location of the positive and negative battery terminals, the battery case mounting provisions, and the type of battery terminal connections are all important factors.

There are also differences in battery capacity. The cranking amp (CA) capacity and cold cranking amp (CCA) capacity are both important factors in matching a battery with a vehicle’s needs. The CA and CCA both refer to the amount of amps available to start the vehicle at a certain temperature. Then there is the reserve capacity (RC) of the battery which is how long a battery can deliver 25 amps of power until it is drained down to 10.5 volts. 

What Is The Right Battery Size For My Car?

If you are trying to find the right battery size for your car then the answer is the size that your vehicle’s manufacturer designed it to use. Trying to shoehorn in a bigger battery may sound like a good idea, but if the battery mount can’t hold it securely then you may end up with a big headache. Likewise picking a smaller battery than specified could lead to electrical issues if it can’t handle the electrical load. It may also rattle around in the battery tray leading to a shorter battery life or even a dangerous short circuit. And even if the car battery group size chart says a battery physically fits, it may be the wrong capacity or voltage. Trust the engineers that designed the vehicle and only replace the battery with an exact size unit. You can change your car battery yourself if you have the proper tools, or let the experts at your local NAPA Auto Care handle it for you.