Let’s take a look at BCI group 34 batteries.
If you’re looking for information or to purchase this type of battery then it’s likely you’re replacing your current one.
You can use your current battery to help you pick a new one as you can compare specifications like application and chemistry types.
Below we will go through all the important aspects to consider including group 34 dimensions, uses, and equivalents. Plus answer all your questions as we go.
⚡BCI Group 34 Key Facts⚡
- Length: 10 1/4 inch
- Width: 6 13/16 inch
- Height: 7 7/8 inch
- Weight: 36 lbs
- 50Ah – 80Ah
- 750 – 900 CCA
- AGM, WET, SLA
- Starting, Marine, Deep Cycle
What is a Group 34 Battery?
BCI group 34 are 12 volt batteries used in a wide array of vehicles, power backups, and off-grid energy systems.
You’ll see them in a number of cars including brands like Chrysler, GM, and Dodge. If you have a Chrysler Concorde, Chrysler LHS, Chrysler Town & Country minivan, Jeep Cherokee XJ, Jeep Liberty, or Dodge Intrepid you’ll likely use a group 34 starting battery.
Along with starting batteries, you can also get hybrid marine to use in boats. These give you a dual purpose with enough cranking power to start an engine, plus the ability to cycle the battery to run electronics.
Group 34 are built as dedicated deep cycle batteries too which means you can use them in RVs, campervans, and power backup systems.
As you can see, there are lots of choices to give you a versatile use. They are mid-sized batteries which give you between 50Ah – 80Ah energy capacity or 750 – 900CCA for starting.
BCI Group 34 Dimensions and Weight
The dimensions of a group 34 battery are:
- Length: 10 1/4 inches (260mm)
- Width: 6 13/16 inches (173mm)
- Height: 7 7/8 inches (200mm)
Group 34R batteries have the exact same dimensions. The only difference is the position of the positive and negative terminals. The ‘R’ specifies that they are reversed, so the positive terminal is on the right, not the left.
A group 34 battery weighs around 36lbs (16kgs). Although this can vary depending on the cell and chemistry type.
Application and Chemistry Type
Group 34 batteries are built for all types of applications including starting, deep cycle, and marine.
This does not mean all are the same and can be used for any purpose. When buying your battery you need to ensure it is built for that specific application. For example, a car needs a group 34 starting battery whereas a boat needs a group 34 marine battery.
Adding to this, you’ll find different options for the cell and chemistry type. This includes lead acid flooded, SLA (Sealed Lead Acid), and AGM (Absorbent Glass Mat).
Be careful when selecting to make sure it is the correct application and chemistry. When replacing a battery you should match the current type. This ensures you have the correct application, and it will charge correctly in your vehicle or system.
Lithium batteries are available in the same dimensions as a group 34. Technically, BCi sizing only refers to lead-acid, but manufacturers design lithium (Lifepo4) to the same specification. Often these give you a higher capacity and reduced weight thanks to increased energy storage density.
Pro tip: Compare the application and chemistry type with your current battery to ensure it matches.
Pros and Cons of Group 34 Batteries
Let’s look at the advantages and disadvantages of these batteries.
Pros:
- Very common and easy to find
- Starting, deep cycle, and marine all available
- Lithium equivalents
- Reverse polarity available
- Lots of equivalents and alternatives
Cons:
- Relatively expensive ($200+)
- Becoming less common
Group 34 vs Group 24 Batteries
Group 34 and group 24 batteries are both commonly used in a wide range of applications. Generally, you’ll see more group 24 marine and deep cycle, whereas group 34 are more abundant for starting.
Many people compare these two groups as they share similar characteristics and dimensions. For example, both are about 10 inches long and 6.8 inches wide. Although, group 24 is 1 inch shorter in height.
| Group | Length (inches) | Width (inches) | Height (inches) |
| 24 | 10 1/4 | 6 13/16 | 8 7/8 |
| 34 | 10 1/4 | 6 13/16 | 7 7/8 |
When it comes to chemistry, you’ll see both groups in all the common types including WET, SLA, AGM, and LifePo4.
Group 34 vs Group 27 Batteries
Group 27 batteries are usually built for deep cycle and marine use, while group 34 can be found for these uses along with engine starting.
As you can see in the comparison below, group 27 are bigger at 12 inches long and 8.7 high. This extra size helps to increase the amp-hour capacity and marine cranking amps.
| Group | Length (inches) | Width (inches) | Height (inches) |
| 27 | 12 1/16 | 6 13/16 | 8 7/8 |
| 34 | 10 1/4 | 6 13/16 | 7 7/8 |
If you’re considering replacing a group 34 with a group 27 in your RV or boat, you should carefully measure your battery compartment to make sure it can fit!
In addition, you should check the chemistry type matches. Group 27 are most common as AGM, but WET and SLA are available in some cases. Of course, group 34 are available in all chemistry types.
Group 34 vs Group 35 Battery
It’s only natural to compare group 35 and 34 batteries as they are in the same BCI class. You would think they are similar due to their number but there are several subtle differences.
Let’s start with the dimensions. You can see on the table below that group 35 is shorter in length by nearly 1 inch and taller by 1 inch. This means you’ll need to measure a battery compartment carefully to check it fits.
| Group | Length (inches) | Width (inches) | Height (inches) |
| 35 | 9 1/16 | 6 7/8 | 8 7/8 |
| 34 | 10 1/4 | 6 13/16 | 7 7/8 |
The application of the batteries can be the same in certain cases. You’ll find both as starting and dual purpose marine. Group 35 deep cycle batteries are rare and more easy to find as group 34. So check the application carefully before making a replacement.
Finally, both are available in various chemistry types including AGM, but WET and SLA, plus LifePo4 are slowly entering the market.
Group 34 vs Group 78 Battery
Group 78 are often considered similar equivalents to group 34. This is because they share the same length and width. In addition, a group 78 is nearly 1 inch shorter in height. This means it would easily fit in a battery compartment.
| Group | Length (inches) | Width (inches) | Height (inches) |
| 78 | 10 1/4 | 7 1/16 | 7 11/16 |
| 34 | 10 1/4 | 6 13/16 | 7 7/8 |
FAQ
Automobiles using group 34 include Chrysler Concorde, Chrysler LHS, Chrysler Town & Country minivan, Jeep Cherokee XJ, Jeep Liberty, or Dodge Intrepid. These are mainly older US made vehicles prior to 2003.
This battery group has a energy storage capacity of 50Ah to 80Ah
Many manufacturers categorize group 34 and group 78 as the same battery. The label denotes that you could use it for both groups. They are similar in size and have the same SAE terminal layout.
It is unlikely you can replace a group 35 with a group 95. This is because they are very different in size, a group 95 is much bigger and heavier.
Summary
I hope this page about group 34 batteries provides you with the answer you require.
As you have discovered, these batteries are built for a wide range of applications. It is a mid-sizes battery with similar dimensions at about 10 by 7 inches.
You can find starting options to crank older American made vehicles, marine hybrid choices for your boat, and deep cycle versions for your RV.
Adding to this, the chemistry type covers all the major lead-acid designs and a growing list of lithium batteries.
