Best Group 8D Batteries: Comparison and Recommendations

Published on: May 11, 2022
Written by Liam Jaxon / Fact-checked by David Rowan

Group 8D batteries are big and bulky lead-acid batteries that can store and release significant amounts of energy in short but powerful bursts or longer. This is why it is pretty popular in automotive, industrial, and marine applications that demand high-capacity, long-lasting batteries that are easy to maintain. 

group 8d batteries

The size and attributes of BCI Group 8D batteries are quite similar to those of BCI Group 6D batteries. I discuss all of the various group 8d battery segments, as well as our preferred one, to assist you to compare and choose between them. Always remember to check how many watts a car battery has and how to choose your battery(Battery group size chart) whenever you buy new batteries, especially ones of this size and cost. 

What Is a Group 8d Battery?

Batteries are classified into “Groups” based on the physical size. Generally, the bigger a battery is, the more volume and output it can produce. A typical Group 8D battery is one of the largest 12-volt batteries available to the general public today.

Because of the massive size of lead-acid, 8D batteries can accommodate more and thicker lead plates within their interiors. In comparison to Group 24 Batteries, Group 34 Batteries, Group 65 Batteries and other battery groups, the additional plates provide more capacity and higher cranking amps. They also lead them to weigh far more than normal. They can deliver up to 1,500 cold-cranking amps(CCA) and recharge in as little as 30 minutes.

With their enormous capacity and strong cranking amps, they are ideal for large RV and boat batteries. Because of their huge capacity, 8D batteries can commonly replace three smaller lead-acid batteries, reducing battery footprint.

Group 8d Battery Specification

  • Group Size: Group 8D;
  • Amp Hours (Ah): 200 to 350 Ah;
  • Cold Cranking Amps (CCA): 1350 to 2250 Amps;
  • Marine Cranking Amps (MCA): 1700 to 2700 Amps;
  • Reserve Minutes: 450 to 780; 
  • Approximate Weight: 130 to 190 pounds;
  • Approximate Dimensions: 20 3/4″L x 11″W x 10″H.

Group 8D Batteries Features

BCI Group 8D batteries are heavy lead-acid batteries used in solar, wind, off-grid, automotive, marine, industrial, and other demanding applications. Check the below features before buying the battery.

Maintenance Free and Safe

Group 8D Batteries are maintenance-free and safe to handle. Most have rope handles, but others may also have holes to tie more ropes if you want to use them as handles. They usually have a flat top with a positive and negative post on one end, but most standard 12-volt batteries have posts on both ends. 

Handle More Cycles

The number of cycles depends on the Depth of Discharge(DoD) and allowable capacity loss. When evaluating a battery’s performance in deep cycle applications (down to 80% of nominal capacity), 50% or 80% DoD is a reasonable starting point. However, manufacturers sometimes report only the number of cycles, not actual capacity loss.

Group 8D Batteries can withstand 500 charging or discharging cycles, with tolerable capacity drops to 80% of nominal capacity on most versions (again, 50 percent DoD, down to 80 percent capacity).

Faster Charging Capacity

Not only do lead-acid batteries perform well, but they also charge more quickly. According to some estimates, a lead-acid battery may charge up to five times faster when equipped with the appropriate charge controller.

Enhance the Function

It is possible to enhance the current capacity of group 8d batteries while simultaneously decreasing charging time and connecting batteries in series. When group 8D batteries are connected in series, their voltage is equivalent to the voltage of a single battery. 

At the same time, their current capacity is equal to the sum of all of their battery capacities. The result of connecting two 12V lead-acid batteries with a combined capacity of 60 Ah in parallel is 12 Volts with a total capacity of 120 Ah.

Integrated Battery Management

8D deep lead-acid batteries are special in that they can handle more starting and deep cycles. They can even deliver more amp-hours than deep cycles. They have thicker insulating separators, stronger plates, and more lead. In brief, they are engineered to withstand deeper discharges than any other marine battery on the market.

Comparison Chart of Popular Group 8D Batteries

ModelBattery TypeChemistryAhCCAMCARCWeight (lbs/kg)Dimensions(LxWxH, inches)
Mighty Max ML8DDeep CycleAGM250600 (@24.5 Amps)159 lbs; 72.0 kg20.47 x 10.55 x 8.66
Renogy 12V Deep Cycle Agm BatteryDeep CycleAGM200~600 (@20 Amps)129 lbs; 58.5 kg20.50 x 9.4 x 9.4
Deka – 8G8D-T975Deep CycleGel22511501470500157 lbs; 71.2 kg20.75 x 11 x 10
Trojan 8D-Gel 12VDeep-CycleGel225500168 lbs; 76 kg20.69 x 10.95 x 10.82
Renogy 12V 200AH BatteryDeep CycleGel200~600 (@20 Amps)127.9 lbs; ~58 kg20.6 x 9.4 x 8.8
ZOOGAMO ZB-12V200AH-B1Deep CycleLiFePO420048056 lbs; 25.4 kg19.5 x 10.6 x 8.8
ExpertPower 12V 200Ah Lithium LiFePO4Deep CycleLiFePO420048048.3 lbs; 21.9 kg20.6 x 9.5 x 8.6 

Our Recommendation of Group 8D Batteries

If you are searching, who makes the best 8D battery? Then you came to the right place where we discussed many models and their acceptance. Most 8D batteries are AGM SLA batteries, with a few Gel-Cell SLA versions and a few Lithium-ion batteries (Lithium Iron Phosphate – LiFePO4). Below is the discussion:

AGM SLA Batteries

An ideal alternative for standby or daily power demands, [amazon link=”B075RGX1WR” title=”Renogy 12V Deep Cycle Agm Battery” /], is designed for solar energy storage applications. This maintenance-free battery performs optimally even at freezing temperatures and is leakproof. Renogy’s AGM batteries keep your car or off-grid solar system running.

These batteries have a high discharge rate, wide working temperature, long life and deep discharge recovery. Besides, the UL Certified Mighty Max Battery Sealed Lead-Acid Battery is ideal for those looking for a long-lasting, rechargeable battery.

It’s a flexible, shock- and vibration-proof rechargeable battery. It also performs high in both hot and cold conditions like Marine Lifeline AGM Battery

The other AGM battery, Universal Power Group UPG 45964, is also a spill-proof and leak-proof rechargeable battery capable of being put in any position and can withstand shock or vibration.

Gel-Cell SLA Batteries

Gel batteries get their name because they use silica or sand to transform the acid inside the battery into a viscous liquid. The Deka – 8G8D-T975 is an SLA gel battery with an amp hour capacity of 20 hours in 225 amp-hours. This gel deep cycle battery does not have any liquid electrolyte that can leak or spill out.

An actual deep cycle gel battery like Trojan 8D-Gel 12V allows you to install it in any position. This GEL battery is high-performance that lasts for a long time in both hot and cold environments. It is shock and vibration-resistant. There is no need for maintenance and an acid pack. 

More than that, the advanced design of the Renogy 12V 200AH Rechargeable Deep Cycle Hybrid GEL Battery works right out of the box and requires no maintenance. Still, it also allows extending the standard life by adding additional electrolytes to the system.

LiFePO4 Batteries

LiFePO4 is a newer lithium solution that is non-combustible and has a lower energy density. Aside from safety, LiFePO4 batteries outperformed other lithium chemistries in high power applications. The most popular ExpertPower 12V 200Ah Lithium LiFePO4. 

can run typical appliances for days, such as an 80W refrigerator for 48 hours ( about 2-4 days ). Its 300Ah capacity is 40% more potent than a comparable lead-acid battery of the same size. 

Also, the POWER QUEEN 12.8V 50Ah LiFePO4 Battery protects the LifePO4 battery from overcharging, over-discharging, over-current, overheating, and short circuits. Simple parallel and series connections increase the capacity and voltage of the lightweight ZOOGAMO 12V 200Ah Lithium LiFePO4 batteries. 


How Many Amp-hours Is an 8d Battery?

The nominal capacity of Group 8D batteries ranges from 220 to 350 AH, while their relative capacity ranges from 1.2 to 1.9 AH per pound of battery mass.

What Is the Difference Between 4D and 8D Batteries?

The key distinctions between 8d and 4d batteries are that 4D batteries are slightly smaller and weigh between 100-150 pounds less than 8d batteries. They have a smaller capacity and cold cranking amps.

What is the Lifespan of 8D AGM Batteries?

Depending on how often you use it, an AGM battery can last anywhere from three to four years if properly maintained. In addition, the quantity of driving you do affects the battery’s lifespan.


BCI Group 8D batteries store a lot of energy and are utilized worldwide. I hope after going through the overall article now you are clear about group 8d batteries and their varieties with comparison. Batteries should be chosen based on personal needs and budget. But make sure you measure the actual battery size, the battery connectors, the battery compartments, and the wires before buying.

Keep in mind that these are huge units that can cause significant damage and possibly injury to humans, children, and pets if mistreated.

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About This Writer

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Hi, I am responsible for the 'Homeowners Power Solutions' category. My name is Liam Jaxon and a licensed technician with 7 years of experience in vehicle batteries, electrical gadgets, and home appliances. My working experience in different residential & light commercial electrical sectors and the automobile industry helped to acquire vast knowledge in this industry.

Hi, I am responsible for the 'Homeowners Power Solutions' category. My name is Liam Jaxon and a licensed technician with 7 years of experience in vehicle batteries, electrical gadgets, and home appliances. My working experience in different residential & light commercial electrical sectors and the automobile industry helped to acquire vast knowledge in this industry.

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