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Knowing the basics of your car—like what size battery it has or what type of oil it needs—will make it easier to keep it in the best working condition. Whether you need a new car battery and are shopping for the correct size or trying to find an appropriate charger, knowing your car’s battery size is handy in many instances.
Below, learn the most common sizes, including BCI Group sizes, the most common types of batteries, and how to determine the right fit for your vehicle.
What Are the Common Car Battery Sizes?
When we refer to a car battery’s size, we’re talking about its physical dimensions. Just because a cell is physically larger doesn’t mean it’s more powerful—it’s just bigger. However, size is crucial because just a millimetre or two of difference requires a different size. To categorise the many sizes, we use group sizes, which help standardise the many batteries available and make it easier to find the proper fit.
If you’re interested in determining your car battery size so you can find the correct charger, rest easy knowing that most sizes can be charged by driving the car, jumpstarting the car with jumping cables, or connecting the battery to a solar battery such as the EcoFlow Portable Power Station by using the EcoFlow Smart Auto Battery Charger as an adapter. The PPS you use will determine how much you can fill up your car’s battery cell.
For example, the EcoFlow DELTA Pro is the top option of the EcoFlow DELTA Series Portable Power Stations. It has a high capacity between 3.6kWh (48V 75Ah) and an output range of 2.6kW, so it can fill more of your car’s battery than a PPS with a lower capacity. You can also pair it with the EcoFlow Smart Generator (Dual Fuel), which runs on gas or propane, for additional energy.
What Are BCI Group Sizes?
BCI Group Sizes are determined by the Battery Council International, a non-profit trade group that leads the North American battery industry, although these sizes are also used elsewhere.
| Group Size | Dimensions | Commonly Seen In |
| 24 | 10 ¼” x 6 13/16” x 8 ⅞” / 260 x 173 x 225 mm | Acura, Infiniti, Honda, Nissan, Lexus, Toyota |
| 24F | 10 ¾” x 6 13/16” x 9”/ 273 x 173 x 229 mm | Acura, Infiniti, Honda, Nissan, Lexus, Toyota |
| 25 | 9 1/16” x 6 ⅞” x 8 ⅞” / 230 x 175 x 225 mm | Toyota, Honda, Nissan, Mazda, Subaru, Acura, Lexus, Infinit |
| 34 | 10 ¼” x 6 13/1”6 x 7 ⅞” / 260 x 173 x 200 mm | Dodge, Chrysler, GM |
| 35 | 9 1/16” x 6 ⅞” x 8 ⅞” / 230 x 175 x 225 mm | Honda, Nissan, Toyota, Subaru |
| 51 | 9 ⅜” x 5 1/16” x 8 ¾” / 238 x 129 x 223 | Honda, Acura, Toyota, Lexus, Mazda, Volvo |
| 51R | 9 ⅜” x 5 1/16” x 8 ¾” / 238 x 129 x 223 | Acura, Honda, Toyoya, Lexus, Infinit, Nissan |
| 52 | 7 5/16” x 5 13/16” x 8 ¼” / 186 x 147 x 210 mm | Ford, Mercury, Lincoln, Mazda, Toyota |
| 58 | 10 1/16” x 7 3/16” x 6 15/16” / 255 x 183 x 177 mm | Mercedes, BMW, Audi, Volkswagen, Porsche, Volvo, Land Rover, Jaguar, Ford |
| 58R | 10 1/16” x 7 3/16” x 6 15/16” / 255 x 183 x 177 mm | Select BMW, Mercedes, Audi, Volkswagen, and Porsche models |
| 59 | 10 1/16”x 7 ⅝” x 7 ¾” / 255 x 193 x 196 mm | Mercedes, BMW, Audi, Porsche, Land Rover, Jaguar, Volvo |
| 65 | 12 1/16” x 7 9/16” x 7 9/16” / 306 x 192 x 192 mm | Ford, Lincoln, Mercury |
*This chart is only for reference. You can find a full list of BCI group numbers and dimensions through the Battery Council.
Car Battery Types
Three primary types of car cells are lead acid, enhanced flooded, and absorbent glass mat.
Lead-Acid Batteries
The most common type is lead acid, which consists of an outer casing and an inner reservoir of battery acid. While these don’t perform as highly as advanced types, they are sufficient for most cars and are pretty affordable.
Enhanced Flooded Batteries (EFB)
EFB batteries, a type of deep-cycle battery, are commonly used in electric vehicles and cars with stop-start technology. Their construction makes them tougher and more durable, so they last longer, but they also come with a higher price tag.
Absorbent Glass Mat Batteries (AGM)
Absorbent glass mat batteries are the most powerful and the most expensive. They are constructed with a fine, absorbent fibreglass mat soaked with battery acid to ensure they’re spill-proof for all off-road applications. This makes them popular for military use and luxury vehicles or sports cars.
How Do I Know Which Car Battery Fits My Car?
If you don’t know what size your car uses, it’s an easy and short process. First, check your owner’s manual for a listing of the car’s recommended BCI size and minimum cold cranking amps (CCA).
You can also visually inspect the current battery if you can’t find it there. The label usually includes the BCI size. If the car’s previous owner installed the current cell, double-check that it meets the requirements listed in the vehicle’s manual.
Finally, if all else fails, you can use online tools to look up the correct size for your specific vehicle. The Battery Council International even sells a complete database of types, sizes, and other details so you can find the best replacement for your car.
Frequently Asked Questions
You can find your car battery’s size by checking the existing cell’s label (usually on the front or top of it), cross-checking that with the vehicle’s user manual, and using online tools to see what options are available for your car.
If you accidentally install a battery of the wrong size in your car, you may have trouble starting the engine, notice an overcharged or undercharged vehicle, or even sustain permanent damage to your car’s electrical system. Avoid these risks by asking a professional what size you need.
Final Thoughts
Getting the right size car battery will ensure your vehicle runs properly, and getting a reliable charging option will ensure you’re never stuck without battery power. When you have an EcoFlow Inverter Generator, you can trickle charge your car cell by pairing it with the EcoFlow Smart Auto Battery Charger. The charger acts as an adapter, allowing you to utilise whatever stored energy in your generator to get your car’s battery filled back up.