Group 24 Vs Group 27 Deep Cycle Battery: Which One Should You Get?

Though both group sizes mentioned in the title are almost the same, there are some subtle differences.

That is why knowing a detailed group 24 vs group 27 deep cycle battery comparison can help you choose the best option.

I have considered several parameters to show their differences which include dimension, terminal orientation, RC, and CCA rating. Without further ado, let’s get started.

Group 24 Vs Group 27 Deep Cycle Battery: 4 Differences to Consider Before Replacing the Existing One

When you are looking for replacing the existing battery in your vehicle, the very first thing to consider is compatibility. You can confirm its fit by reading the dimension difference in both groups.

Also, there are a few more important parameters to keep in mind. Here, I have described them all for your convenience.

1. Difference: Dimensions

The width and height of both group 24 and 27 batteries are the same. Their only difference is in the length.

Group 24 deep cycle batteries are 10.25 inches or 26 cm long, and group 27 deep cycle batteries are 12.06 inches or 30.6 cm long.

2. Difference: Terminal Positions

Another minor difference is in their terminal orientation. I have shortly reviewed a few products from both groups. Check the links, see their pictures, and decide which one fits your vehicle.

3. Difference: RC Rating

Approximately group 27 has a 20% larger dimension compared to its counterpart. And, it is also true for the reserve capacity.

Now, you can understand that different brands and models have various RC ratings. This is why, it is not possible to mention a specific number, and tell how much more group 27 has to offer.

I can make an estimation. According to the research, the average reserve capacity of the popular group 24 battery models is 140 to 175 minutes. On the other hand, 27 batteries offer 170 to 220 minutes which is way more.

4. Difference: CCA Rating

Like the previous comparison regarding RC rating, it is not possible to show exact numbers for the CCA rating of these batteries. All I can do is show the data of two batteries and give you a rough idea.

NORTHSTAR Group 27 Battery features a 930 CCA rating which is more than NORTHSTAR Group 24F Battery (840 CCA).

Which Group Size Deep Cycle Battery Is Better: 24 Or 27?

Besides all those differences in the detailed comparison, there is also a visible gap in power between them.

To give you a perspective, I am going to compare the Ah difference in Mighty Max Batteries. A group 24 Mighty Max battery has 75Ah where the group 27 model has 100Ah.

As I have presented everything about the two stated BCI battery groups, it is clear as daylight that group 27 batteries ace in all aspects.

If it is possible for you to buy a group 27 battery instead of the existing group 24 model, I will highly recommend spending some more and changing the group size.

And, those who already have been using the best type in this comparison should stick to it.

But you should check out the product recommendation I have given below so that you can enjoy the best features and benefits of this group size.

What Is the Best Group 24 Battery?

1. Best Overall: ACDelco M24AGM AGM Voyager

I like this AGM battery from ACDelco as one doesn’t need to spend time on its maintenance. It offers deep cycle performance with enough safety. You don’t have to worry about acid-related accidents or leaks. 500 CCA rating and lower self-discharge rates make it suitable for harsh weather and off-season storage.

2. Runner-Up: Universal Power Group UB12750

Universal Power Group UB12750 is a very popular general-purpose deep cycle battery in the BCI Group 24 category. It is affordable, has good cycle life, and is spill-proof housing. If the electronic component draws less than 25 amps, you can get up to 2 hours of backup time.

3. Best Budget: Interstate (DCM0035) SLA AGM

You will be glad to know that the battery is made with VRLA technology to prevent any kind of accident due to a spill or physical impact. People like it for its durable construction and affordable pricing. It can handle constant deep discharges in vehicles. The credit goes to its thicker lead plates which are perfect for deep cycles.

What Is the Best Group 27 Battery?

1. Best Overall: VMAX MR127 AGM

As it is a marine battery, you can expect it to perform both indoors and outdoors. Durable build quality is another big advantage of MR127 which features industrial-grade plastic and tin alloy plates. Also, you don’t have to worry about spillage. Furthermore, the battery doesn’t take long to fully recharge.

2. Runner-Up: Optima D27M BLUETOP

What makes Optima D27M BLUETOP unique is its spiral-cell technology. Hence, D27M is a better performer than the lead-acid counterparts. This battery features an 800 CCA rating and comes with 140 minutes reserve capacity. It has a cast cell connection making it safe from harsh conditions of the road. Another popular brand is Odyssey. Read my full comparison of odyssey vs optima battery to know which brand is better.

3. Best Budget: Universal Power Group VRLA Battery

At an affordable price, you can get an AGM deep cycle battery of group 27 which can absorb sulfuric acid making it leak-proof. Also, the build quality of this VRLA battery doesn’t require any maintenance and supports fast charging. As it can hold a charge for a long time, you can store the battery in off-seasons.

frequently asked questions (FAQs)

Are 24 and 27 batteries the same size?

From the measurements I have given at the beginning of the discussion, you will notice that both group size batteries have the same width and height. And, there is a slight difference in the length which is 1.8125 inches or 46 mm.

What does battery group size 27 mean?

Group size 27 means a specific battery type with a certain dimension, weight, and capacity. According to the BCI standards, the dimension must be very close to 306 x 173 x 225 mm.

After reviewing the specs of different brands’ products of this group size, I have come to know that they feature 20h capacity in the 66 Ah to 110 Ah range.

Also, their CCA rating is somewhere between 600 and 1000 along with an RC of 140 to 220 minutes. Such a difference is because of the various battery chemistry and technology used by different brands.

What does Group 24 mean on a battery?

Like the previous answer, Group 24 batteries must be produced maintaining a dimension of 260 x 173 x 225 mm. Because of their smaller size compared to group 27, the RC is slightly less.

What cars use a Group 24 battery?

Some of the most popular car brand series named Lexus, Honda, Toyota, Infiniti, Nissan, and Acura is compatible with group 24 batteries. Also, you will find older American cars using this BCI group size.

What vehicle uses a Group 27 battery?

Besides some old American car models and boats, some Honda and GM vehicles use group 27 batteries.


Now, you have a clear overview of group 24 vs 27 deep cycle battery comparison. For car or truck owners, it is hard to do anything else besides the factory default group size.

But for boaters, it is not a big deal. And, you have seen from the comparisons that a group 27 deep cycle battery is larger than a group 24 deep cycle battery.

Therefore, it is ahead of group 24 in all other aspects. If you need more power and does not have any compatibility issue, you must get the best group 27 battery I have recommended above.

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