Group 42 car batteries are highly favored by vehicle owners for their dependable performance and versatility in working with various applications. In this detailed guide, we will delve into the fundamental features of Group 42 batteries and highlight what sets them apart from other battery groups.
General Characteristics
Group 42 batteries are known for their optimized size and performance, making them a versatile choice for various automotive applications.
- Physical Dimensions: The standard dimensions are approximately 9.5 inches in length, 6.9 inches in width, and 6.9 inches in height. This battery’s optimized size makes it a popular choice for many vehicles as it fits well in most car battery trays.
- Voltage and Terminals: All Group 42 batteries provide 12V DC power with standard SAE side-mounted top terminal posts using L-connectors. This standard configuration ensures compatibility with a wide range of vehicles and applications.
- Cold Cranking Amps (CCA): A minimum rating of 500 CCA is typical for Group 42 batteries, but high-performance versions can exceed 800 CCA. Higher CCA improves starting reliability in cold weather, making this power supply suitable for a wide range of climate conditions.
- Capacity: Group 42 batteries typically range from 50-75 Ah (amp-hours), with 70 Ah being the most common. More reserve capacity allows the battery to run vehicle electronics if the alternator fails, providing added reliability and performance.
Group 42 Battery Dimensions
Battery Design |
---|
![]() |
Dimensions and Sizes (Length x Width x Height) |
---|
9.5625'' x 6.9375'' x 6.9375'' Inches 242 x 175 x 175 Millimeters |
Group 42 Battery Post Terminals
Post Terminal Types and Locations | Posts Used |
---|---|
![]() |
Type "A", "A1" or manufacturer's custom post design |
Group 42 Battery Voltage and Current Characteristics
Volts | Cells | CCA Range |
---|---|---|
12 | 6 | 210-650 |
Best Group 42 Batteries
List of recommended batteries
Good Choice
![]() |
SLI42/58R Duracell Ultra Flooded 580CCA BCI Group 42 Heavy Duty Battery
|
Check Price |
Good Choice
![]() |
EverStart Maxx Lead Acid Automotive Battery, Group Size T5 650 CCA
|
Check Price |
Good Choice
![]() |
Super Start Premium Group Size 42 Top Post Battery 500 CCA
|
Check Price |
Good Choice
![]() |
DieHard Silver Battery, Group Size 42, 495 CCA
|
Check Price |
Group 42 Alternatives and Closest Battery Groups by Dimensions
Interchangeable Battery Groups for 42 Battery
These groups have the same dimensions and performance but can have different terminal post types, post locations, and polarity.
Battery Group Number | Dimensions | Shape | Volts | Cells | Post Terminal Type |
---|---|---|---|---|---|
Group 42 Battery | 9.5625'' x 6.9375'' x 6.9375'' in. 242 x 175 x 175 mm |
![]() |
12 | 6 | "A", "A1" |
Group 90 Battery | 9.5625'' x 6.9375'' x 6.9375'' in. 242 x 175 x 175 mm |
![]() |
12 | 6 | "A1", "A2" |
Similar Battery Groups With the Same Length, Width and Voltage
These dimensions will fit you in 99% of cases when you want to use a different battery group instead of a 42 battery since most battery compartments have a height margin and strict limitations on height and width only, which match batteries in the table below. Please check the battery compartment before you buy a battery from this group.
Battery Group Number | Dimensions | Shape | Volts | Cells | Post Terminal Type |
---|---|---|---|---|---|
Group 42 Battery | 9.5625'' x 6.9375'' x 6.9375'' in. 242 x 175 x 175 mm |
![]() |
12 | 6 | "A", "A1" |
Group 47 Battery | 9.5625'' x 6.9375'' x 7.5'' in. 242 x 175 x 190 mm |
![]() |
12 | 6 | "A", "A1", "F" |
Closest but not Identical Size Battery Groups
Battery groups in this section below are not identical to the group 42 battery, they can be a little bigger or smaller. Please pay attention to the post terminal types and their location
Closest Groups that Have Slightly Smaller Dimensions
Smaller batteries can have less capacity, performance, and power in comparison with 42 group.
Battery Group Number | Dimensions | Shape | Volts | Cells | Post Terminal Type |
---|---|---|---|---|---|
Group 42 Battery | 9.5625'' x 6.9375'' x 6.9375'' in. 242 x 175 x 175 mm |
![]() |
12 | 6 | "A", "A1" |
Group 22F Battery | 9.5'' x 6.9375'' x 8.3125'' in. 241 x 175 x 211 mm |
![]() |
12 | 6 | "A" |
Group 96R Battery | 9.5'' x 6.9375'' x 6.9375'' in. 242 x 175 x 175 mm Positive post on the Right |
![]() |
12 | 6 | "A", "A1" |
Group 67R Battery | 9.125'' x 6.9375'' x 6.9375'' in. 231 x 175 x 176 mm Positive post on the Right |
![]() |
12 | 6 | "A" |
Group 86 Battery | 9.0625'' x 6.8125'' x 8'' in. 230 x 173 x 203 mm |
![]() |
12 | 6 | "A" |
Group 85 Battery | 9.0625'' x 6.8125'' x 8'' in. 230 x 173 x 203 mm |
![]() |
12 | 6 | "A" |
Group 55 Battery | 8.5625'' x 6.0625'' x 8.375'' in. 218 x 154 x 212 mm |
![]() |
12 | 6 | "A" |
Closest Large Dimensions
Bigger batteries can have more capacity and power compared to 42 batteries.
Battery Group Number | Dimensions | Shape | Volts | Cells | Post Terminal Type |
---|---|---|---|---|---|
Group 42 Battery | 9.5625'' x 6.9375'' x 6.9375'' in. 242 x 175 x 175 mm |
![]() |
12 | 6 | "A", "A1" |
Group 97R Battery | 9.9375'' x 6.9375'' x 7.5'' in. 252 x 175 x 190 mm Positive post on the Right |
![]() |
12 | 6 | "A1", "A2" |
Group 58 Battery | 10.0625'' x 7.1875'' x 6.9375'' in. 255 x 183 x 177 mm |
![]() |
12 | 6 | "A" |
Group 58R Battery | 10.0625'' x 7.1875'' x 6.9375'' in. 255 x 183 x 177 mm Positive post on the Right |
![]() |
12 | 6 | "A" |
Group 59 Battery | 10.0625'' x 7.6875'' x 7.75'' in. 255 x 193 x 196 mm |
![]() |
12 | 6 | "A" |
Group 101 Battery | 10.25'' x 7.0625'' x 6.6875'' in. 260 x 179 x 170 mm |
![]() |
12 | 6 | "S" |
Group 78 Battery | 10.25'' x 7.0625'' x 7.3125'' in. 260 x 180 x 186 mm |
![]() |
12 | 6 | "S" |
Group 100 Battery | 10.25'' x 7.0625'' x 7.375'' in. 260 x 179 x 188 mm |
![]() |
12 | 6 | "S" |
Group 124R Battery | 10.375'' x 7'' x 8.625'' in. 262 x 177 x 218 mm Positive post on the Right |
![]() |
12 | 6 | "A" |
Group 36R Battery | 10.375'' x 7.1875'' x 8.125'' in. 263 x 183 x 206 mm Positive post on the Right |
![]() |
12 | 6 | "A" |
Group 124 Battery | 10.4375'' x 6.9375'' x 8.4375'' in. 265 x 175 x 214 mm |
![]() |
12 | 6 | "A" |
How to Get 24 Volts from 12V of a 42 Battery Group
If you need 24 Volts, you can connect two group 42 batteries in series to double the voltage. The voltage of a series connection is equal to the sum of the voltages of all its batteries. If one 12V lead-acid battery is connected to another 12V lead-acid battery, you have 24V total power output. Each battery must be fully charged and completely isolated from the other before connecting them in series, or there will be damage to at least one of them.
Increasing a Capacity of 42 Batteries with a Parallel Connection
If you need to increase current capacity and reduce charging time, connect batteries in parallel. When group 42 batteries are in parallel, their voltage is equal to the voltage of one battery, while current capacity equals to the sum of all its battery capacities. If you have two 12V lead-acid batteries with 60 Ah capacity and you connect them in parallel, you'll get 12 Volts with 120 Ah.
ArrayAdvantages over alternative solutions
Group 42 batteries offer several advantages that distinguish them from other battery groups. Here are some key points of comparison:
- Optimized Size: The optimized size makes them a versatile choice for various automotive applications. Their compact dimensions allow them to fit well in most car battery trays, providing a wide range of vehicle compatibility.
- Reliable Performance: Group 42 batteries are known for their reliable performance, with a minimum CCA rating of 500 and a typical capacity of 70 Ah. This ensures that they can provide reliable starting power and run vehicle electronics if the alternator fails.
- Versatility: Group 42 batteries are suitable for a wide range of climate conditions, making them a versatile choice for various geographic regions. Their high CCA rating and reserve capacity make them suitable for both cold and hot weather conditions.
When to Choose Group 42 Batteries
The Group 42 strikes an optimal balance for many drivers. It fits easily into 1990s – 2000s model BMW 3 Series, Honda Accord and Civic, VW Golf and Jetta, and Toyota RAV4 vehicles with ample power. Choosing Group 42 over Group 35 batteries provides longer lifespan and reliability without the hassle and cost of resizing the tray for larger groups.
Premium Group 42 batteries with 800+ CCA offer extreme cold weather starting performance to handle winter weather, even in northern regions. And all BCI group standard batteries have interchangeable dimensions in case you need an emergency replacement from a different brand.
In summary, the Group 42 hits a sweet spot for battery tray fitment, capacity, power, and cost.
Vehicle Fitment
The Group 42 battery has an optimized footprint to fit these common vehicles:
- BMW 3 Series (E36, E46)
- Honda Accord, Civic
- Toyota RAV4
- Volkswagen Golf, Jetta, Passat, Beetle
It may also be compatible with vehicles from Mercedes, Chrysler, Mazda, Subaru, and other manufacturers. Always check your owner’s manual or an online fitment guide before purchasing.
*While Group 42 batteries may be compatible with these vehicles, the specific fitment should always be verified using the owner’s manual or an online fitment guide before purchasing
In summary, Group 42 car batteries are a dependable and flexible option suitable for various automotive uses. Their size and performance are optimized for reliable and versatile performance, which makes them a popular choice among drivers. Comparing the overall features of Group 42 batteries with alternative options can help you select the best battery for your vehicle.

Eric Strong works in the automotive repair industry more than 12 years. His work included repairing electrical systems in various vehicle systems. A hybrid electric car battery replacement experience expanded his understanding of automotive battery technology.
Page Contents