51R VS 35 Battery: Head-to-Head Comparison

There are only 7 battery sizes that are common in car battery usage. But still, owners become confused about which should fit in their car. This is because car batteries have different names and are standardized by different authorities.

Cars that are manufactured in different regions have different measurements of batteries. However, car batteries have alternatives for use. 

Here, we have group 51R VS group 35 head-to-head battery comparison, so you can choose a better alternative if you need it.

Group 35 VS 51R Battery: An Overview 

Group 51R and group 35 car batteries are common in older American and Japanese cars. BCI batteries are very common in the USA, but the same types of batteries are used in Europe or other regions with different names. 

Group 35 Battery is also known as Q85. It is commonly used in Japanese Cars, basically in Trucks from Toyota, Mitsubishi, Subaru, and Nissan.  Some older American Cars also use group 35 batteries. 

Group 51R is slightly more common than Group 35 but lighter versions. Japanese Cars, Hondas, Nissan and GTRs, use Group-51R Battery.

The 51R has a significant terminal structure; its positive terminal is on the right. In its name of 51R, ‘R’ refers to the right.

However, both have individual specs you should know for your better choice. Here we have the most common specs, which are the same in all 51R and group 35 batteries. 

Group 51R VS Group 35: Comparison Table 

Specifications Group 51R Group 35
Dimension  9.374 x 5.0625 x 8.8125 inches 9.06 × 6.87 × 8.8 inches 
CCA 310-500 CCA 620-850 CCA
RC 60 – 85 RC 90-130 minutes
Weight 10 – 45 pounds  16 – 50 pounds. 
Position of positive Terminal  Right  Left

51R Battery Specifications 

Group 51R is a BCL battery that measures 9.374 x 5.0625 x 8.8125 inches (23.8 x 12.9 x 22 3 cm). It can easily fit in a rectangular box which is ideal for large and older car models. 

Generally speaking, 51R batteries have 36 – 45 amp hours (Ah), 450 500 CCA of cold cranking amps and 60 -75 reserve capacity RC. Its weight is 10 to 45 lbs depending on the manufacturer.

51R is significant for its vibrant resistance feature. Those who drive off-road have a fast and rough driving style. 51R remains in place in bumpy conditions that make the ride convenient. 

35 Battery Specifications 

Group 35 is a BCI battery that is also known as Q85. In inches, its dimension is 9.06 × 6.87 × 8.8. Weight differs in different manufacturing companies. 

But it’s approximately between 16 to 50 pounds. Group 35 has a 20-hour capacity in the 44-65 Ah range as a medium size car battery. It can provide  620-850 CCA and have 90-130 minutes RC. Besides, it can deliver 40 AMP hours.

However, different manufacturers make it differently under preferable demands. But all Group 35 batteries have the same specifications that are mentioned here. 

Group 51R VS Group 35: Difference

As you see above,  we have too many differences between 51R and Group 35 batteries. But the main difference is the position of the positive terminal. 

51R has its positive Terminal in the right side, but Group 35 has the opposite, Which means on the left. Normally, Japanese cars have their positive Terminal on the right side. That’s why the 51R is very common in Japanese cars.

On the other hand, Group 35 batteries are common in older American car models.

The 51R battery is lighter than the Group 35 battery. However, 35 have more RC, CCA and Amp hours than 51R battery. 

Group 51R VS Group 35: Which One is Better?

Both 51R and Group 35 have different usages. To illustrate,  BCI Group 51R batteries widely use general-purpose or auxiliary batteries. It’s reliable for continuous power supply in many conditions like ignition and dual-purpose batteries. 

It’s lightweight and preferable for racing.   In older American cars, trucks, and RVs, Group 35 is a common lead acid battery which is used for starting or dual purposes.  

In the market, both types of batteries have various brands which fit perfectly in different measured cars. Before you buy anyone, you just need to confirm your battery measurements and find something similar to yours.

Final Words

Cars have various group-size batteries from different manufacturers. So we all get puzzled when we have to buy a new one. But It’s not that hard to buy if you know the specs and features of your car batteries. 

51R and Group 35 are common in older cars, so this article tries to specify all similarities and differences, including their features, so you can find the good one.

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