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marine battery group size chart

by Mr. Derek Jenkins Published 3 years ago Updated 2 years ago

Marine Battery Group Size Chart

Battery Group Size Length (inch) Width (inch) Height (inch)
U1 7 3/4 5 3/16 7 1/8
21 (R) 8 3/16 6 13/16 8 3/4
22F 9 1/2 6 7/8 8 5/16
22HF 9 1/2 6 7/8 9
May 23 2022

Marine Battery Group Size Chart – Common Sizes
Group SizeLengthHeight
259-1/16”8-7/8”
27M12-1/2”9-3/4”
31M13”9-7/16”
34M10-1/4”9-7/16”
4 more rows

Full Answer

What exactly are marine battery group sizes?

The term “group size” refers to the dimensions and power capacity of a battery. It is used for all batteries, not just marine batteries. Group size is usually shown as a mix of letters and numbers. For example, 24M. “24” is the size and “M” stands for “marine.” Why does battery group size matter?

What are the dimensions of a marine battery?

Quick Answer: The 7 Best Rated Marine Batteries For 2021

  • VMAXTANKS AGM Marine Deep Cycle Battery
  • Universal Power Group Deep Cycle Lead Acid Battery
  • Odyssey 31-PC2150S Marine Starting Battery
  • Optima Batteries BlueTop Marine Starting Battery
  • Optima Batteries YellowTop Dual Purpose Battery
  • Odyssey Thunder Marine Dual Purpose Battery
  • Optima Batteries BlueTop Dual Purpose Marine Battery

What is the best dual purpose marine battery?

#6 Odyssey Thunder Marine Dual Purpose Battery

  • Type: AGM / SLA (Absorbent Glass Mat, Sealed Lead Acid)
  • Size & Weight: L 13″ x W 6.7″ x H 9.3″, 71 lbs
  • Capacity: 100Ah
  • CCA: 1150 A
  • Charging Current & Voltage: 25A, 14-15V
  • Expected lifespan: 8-10 years in float mode.

What are marine battery groups?

What Exactly are Marine Battery Group Sizes?

  • A General Description. The BCI or Battery Council International created this battery size chart to standardize the industry.
  • Associations With Amp Hours. ...
  • Going With the “M”. ...
  • Customizing the Boat’s Power. ...
  • Considering Extra Power. ...
  • Prolonging the Battery’s Lifespan. ...

What is group size on marine battery?

Batteries come in range of sizes. Terms that you will often hear are group 24, 27, 31, 4D, and 8D. The group has nothing to do with the actual capacity of the battery, but merely relates to the physical size. Another factor to consider is the actual battery capacity.

What is the difference between Group 24 and Group 27 battery?

If you compare a group 24 battery and group 27 deep cycle battery together, you'll notice that the mp hours are slightly higher on the group-27 product. This specification difference is made on purpose by the manufacturers. In general, a group size with a higher number has more amp hours than lower values.

How do I know what size marine battery I need?

What kind of battery goes in a boat? In most cases, 12 volt batteries are what you need. In rare cases other types of batteries are used, like 6 volt or 8 volt batteries for example. If your boat is a bass boat or bigger, 12 volt boat battery is your best bet.

What is the difference between a Group 31 and Group 34 battery?

Their group 31 is a 96 AH battery and the group 34 is a 62 AH battery. I might eventually add a solar panel to supplement this setup and provide additional power for other accessories/gadgets when camped for longer periods of time.

Can I use a Group 27 battery in place of a group 24?

However, these batteries are not exactly the same and they should not be used interchangeably unless explicitly permitted by the manufacturer of the intended application/service/tool. Published: July 20, 2021.

What does the 27 mean in a deep cycle battery?

Group 27 batteries are rather large and powerful batteries, featuring 20h capacity in 66-110 Ah range, providing 600-1000 CCA, 140-220 minutes RC, etc. Their weight depends on the internal construction and it ranges between 54 and 70 pounds (24.5 - 32 kg).

What do battery group sizes mean?

Car and Truck Battery Group Size This refers to the battery size that will best fit the physical dimensions, terminal locations and type required for your vehicle.

What are battery group numbers?

BCI have defined Group Numbers to categorize differences between various batteries. The grouping is based on the physical dimension of a battery to best fit your vehicles. It has nothing to do with the capacity of the batteries.

What are the different battery groups?

In general, these more-common battery group sizes are 24, 24F, 25, 34, 35, 51, 51R, 52, 58, 58R, 59, and 65. Helpful Hint: Some vehicles can handle a larger battery than was originally installed. A physically larger battery usually has more power and reserve time than a smaller battery.

What is the difference between a Group 24 and Group 34 battery?

The OPTIMA Group 34 battery is an AGM (absorbed glass mat) lead-acid battery, while the Group 24 is a flooded lead-acid battery. The OPTIMA uses 99.99% pure virgin lead, which reduces corrosion, while the Group 24 battery uses recycled lead.

What does the R stand for in a group 34R battery?

Group 34 Batteries vs Group 34R Batteries Generally, the only difference among the group 34 batteries and group 34R batteries is the terminal posts orientation. While 34 group batteries feature positive terminal on the left, 34R group batteries feature positive terminal on the right, hence the 'R' letter after '34'.

What does 31 mean on a battery?

The most common Group 31 batteries are lead-acid batteries (AGM, flooded cells, and gel cells) and Lithium Iron Phosphate (LiFePO4) batteries.

What size battery does my boat need?

If you don't know much about boat battery sizes, then you'll have to consider a few factors before getting a marine battery for the boat. Furtherly...

What is the difference between a Group 24 Marine Battery and Group 27 battery?

Considering the BCI size number of the batteries, group size 24 has a lower capacity as compared with group size 27. Moreoverfboa, the charging cap...

What does the group size mean on a marine battery?

The battery's group size is basically one of the numeric aspects of the battery labeled on it. Additionally, you can also consider it as a physical...

Is there a difference between deep-cycle and marine battery?

Deep cycle batteries can also be one of the types of a marine batteries. As compared with the cranking (starter) battery, deep cycle batteries are...

What type of battery is a marine deep cycle?

Well, the flooded lead-acid battery is the most often used marine battery type. However, there are basically two types of the marine deep cycle, in...

What makes a marine battery different?

Marine batteries have a unique body construction coming with a firm combination of thin plates. As we know, there are lots of batteries in the star...

What voltage is a marine battery?

The marine battery charge criteria is a major thing to consider for managing the voltage of the battery. The marine battery should be kept at 13.2...

What are marine batteries?

Marine batteries come in three main types that include deep cycle, starting, and dual-purpose. Deep cycle batteries are designed to provide continuous power for long periods. Deep cycle batteries are used to power house loads that commonly include navigation aids, fish finders, running lights, radios, and trolling motors. Conversely, starting batteries provide a short high current burst to crank an engine. Lastly there are dual purpose batteries that can perform both deep cycle and cranking duties. The RELiON HP line ( RB100-HP and RB300-HP included in the size chart below) are dual purpose models capable of providing up to 800 amps for two seconds to start your boats motor.

How many batteries can I use for a 24 volt motor?

If you have a 24-Volt motor, you can use two, 12-Volt batteries in series with a multi-bank charger or multiple 24-Volt batteries in parallel to meet your capacity requirements. If you have a 36-Volt motor you can use three, 12-Volt batteries in series with a multi-bank charger.

How many volts for a trolling motor?

Marine electrical systems are commonly set up in 12, 24, or 36 volts depending on the size of the watercraft and its trolling motor. If you have calculated your power needs as we referenced at the beginning of this blog, you can achieve the voltage and capacity your setup requires. If you have a 12-Volt trolling motor, you can choose from the 12V options that will suit your capacity requirements. If you have a 24-Volt motor, you can use two, 12-Volt batteries in series with a multi-bank charger or multiple 24-Volt batteries in parallel to meet your capacity requirements. If you have a 36-Volt motor you can use three, 12-Volt batteries in series with a multi-bank charger. We also have a diagram that can be used to help wire your 36V system with a HP battery for cranking that can be found below.

What is BCI in battery industry?

BCI is a non-profit trade association that was developed in the 1920’s to promote the interests of the lead-acid battery industry (1). Through the years, BCI has developed technical standards that include size groups for common battery applications.

Why are group sizes important?

Because equipment manufacturers try to minimize battery storage space, these group sizes define general battery dimension. Typically, the larger the group size, the larger the overall dimensions (and capacity) of the battery.

How long does a deep cycle battery last?

If you take the marine battery off the boat, the charging session should last between 14 and 16 hours, reports Battery University.

What is the difference between a group 24 and a group 27?

Associations With Amp Hours. If you compare a group 24 battery and group 27 deep cycle battery together, you’ll notice that the mp hours are slightly higher on the group-27 product. This specification difference is made on purpose by the manufacturers. In general, a group size with a higher number has more amp hours than lower values.

Why use dual purpose batteries?

The dual purpose product supports your marine accessories so that you can lower the strain and costs on the other batteries. Add these accessories to your extra battery, such as: By removing the accessories from the main batteries, you allocate their power to the engine and critical operations.

Can you use a boat battery without the M?

Although you may find the right group size for your vessel, don’t use a battery without the “M” designation. The internal construction won’t work in the long run for your boat. Batteries will decline with rapid ease. Don’t leave yourself stranded with an improper battery.

What is the best source of information to find the recommended battery group size and specifications?

The best source of information to find the recommended battery group size and specifications is your Owner’s Manual.

What is the most common battery group for electric cars?

The most common battery groups for electric and hybrid cars are GC2 and CG2H, which are a 3-cell battery. However, batteries for electric and hybrid cars also come in 4-cell and 6-cell versions. These include GC8, GC8H, and GC12 battery groups.

What is a BCI 35 battery?

A BCI Group 35 battery is a standard battery size for a wide range of cars and small trucks. It has a top-post design and fits popular models, including Toyota, Nissan, KIA, Ford, and other models. It is the recommended Honda Accord and CR-V battery for many models.

What does BCI stand for in batteries?

These numbers and letters are the BCI group size of the battery. BCI stands for Battery Council International.

What is a BCI group 100?

By comparison, A Group 100 and 101 are automotive batteries that have the posts located on the side, and the left post is the positive terminal. This should give you an idea of what the different BCI group numbers mean when you are looking for your next battery.

What happens if you put a bigger battery in your car?

On the other end of the spectrum, if you put a battery that is larger than recommended, it can cause significant damage to your car. The larger battery can cause spikes and power surges that can damage your electronics, including your onboard computer.

What is universal battery number?

A universal battery number is simply another battery naming system. They are still in different sizes and shapes. These numbers usually begin with UB followed by a sequence of five numbers and another set of five letters and numbers separated by a hyphen.

What is BCI in boating?

Battery Council International (BCI) The BCI created and maintains an international chart that defines the battery size groups. This is one of the specifications you need to look out for because not only does the battery need to produce enough power, but it also needs to fit in the space in your boat.

What to do if you can't find your battery category?

If you can’t find your category on the battery, then you should check your owner’s paperwork. The battery category will be listed here. If you don’t have the original paperwork, then your final option is to ask an expert or boat mechanic to help you identify your battery.

What does higher category number mean?

You will notice that the higher the category number, the more amp hours the battery has. Manufacturers do this on purpose. It means that the battery will have more power as the day goes on.

Do all boats need a battery?

Since all boats need a battery, there’s a wide variety of marine battery sizes available. Knowing the size you need is vital to ensure your new battery will fit on your boat and be strong enough to power everything you need. Use this guide to help you buy your next marine battery.

Can you use a marine battery from the other categories?

Those with an “M” are specifically designed for marine use. Now, this doesn’t mean you can’t use a battery from the other categories. But you need to understand that batteries not designed for marine use will not last as long.

How to choose the right size battery for a boat?

When it comes to picking the right size of battery for your boat, that first thing you have to do is to determine the actual electrical load of the boat. It will give you an idea of how much power do you need to crank up its engine and at the same time power all of the boat’s electrical components and accessories . Once you have an idea of the enough power that you need , you can now then identify what size of battery you are going to need.

What does a marine battery do?

The marine battery you will purchase should also have the ability to keep up with the demands of your boat to make sure that your boat will provide the performance that you need.

How does reserve capacity work on a boat battery?

The reserve capacity of a power cell indicates the amount of time it can stand on its own and provide the power your boat needs for its electrical components. It tells about the amount of time a fully charged marine battery requires to drop below 10.5 volts if it is discharging 25 amps. The larger the electrical load of your boat, the higher the reserve capacity it needs to be able to run the entire electrical grid relying on the battery alone. Batteries with higher reserve capacity can be a bit expensive, so make sure to weigh all your options carefully to come with a smart decision.

How to find the right power cell for a boat?

If you are trying to find the right suitable power cell for your boat, you first have to determine the entire electrical load of your boat and the current that it needs to start its engine. As we mentioned above, your marine battery will have to handle two tasks. Starting your boat’s engine and running its entire electrical grid. If you have an estimated value of these two things, then you will have an idea of what kind of battery you need to handle these two crucial tasks.

Why do you need a cold cranking amp for a boat battery?

It indicates the battery’s ability to provide enough power to start your boat’s engine in cold weather or low-temperature conditions. The higher the CCA or cold cranking amp rating the battery has, the better for you boat.

What is deep cycle battery?

Compared to the first type of battery, deep cycle batteries are capable of providing enough power for longer periods of time.

Do boats need batteries?

Boats come in various sizes, and they also come with different accessories, then you need the right type and size of the battery to power them all. The larger the boat and its electrical load the larger the battery it needs to get enough amount of power that it needs.

BCI Battery Group Sizes

Image
We’ll start with a quick history lesson on what Battery Council International (BCI) is, what BCI group sizes entail, and how RELiON Lithium batteries fit within the BCI sizing scheme. BCI is a non-profit trade association that was developed in the 1920’s to promote the interests of the lead-acid battery industry (1). Through the …
See more on relionbattery.com

Types of Marine Batteries

  • Marine batteries come in three main types that include deep cycle, starting, and dual-purpose. Deep cycle batteries are designed to provide continuous power for long periods. Deep cycle batteries are used to power house loads that commonly include navigation aids, fish finders, running lights, radios, and trolling motors. Conversely, starting batteries provide a short high curr…
See more on relionbattery.com

Common Trolling Motor Battery Configurations

  • Marine electrical systems are commonly set up in 12, 24, or 36 volts depending on the size of the watercraft and its trolling motor. If you have calculated your power needs as we referenced at the beginning of this blog, you can achieve the voltage and capacity your setup requires. If you have a 12-Volt trolling motor, you can choose from the 12V o...
See more on relionbattery.com

A General Description

  • A battery group size refers to the product’s physical dimensions, including: 1. Length 2. Width 3. Height The BCI or Battery Council International created this battery size chart to standardize the industry. By selecting a group 24 battery, for example, you know the exact size that you’re purchasing. Regardless of the battery’s manufacturer, the gr...
See more on northeastbattery.com

Associations with Amp Hours

  • If you compare a group 24 battery and group 27 deep cycle battery together, you’ll notice that the mp hours are slightly higher on the group-27 product. This specification difference is made on purpose by the manufacturers. In general, a group size with a higher number has more amp hours than lower values. This fact translates to more power in your battery as the day goes on. You sh…
See more on northeastbattery.com

Going with The “M”

  • Along with the group-size numbers, you might see letters printed on your battery. For marine applications, look for group sizes indicating the letter “M.” These batteries are designed for watercraft applications. Although you may find the right group size for your vessel, don’t use a battery without the “M” designation. The internal construction won’t work in the long run for your …
See more on northeastbattery.com

Customizing The Boat’S Power

  • You might discover that an enhanced battery might help your progress on the water. The battery’s tray, however, limits the marketplace sizes. You can change battery sizes by upgrading your tray. Pay careful attention to the surrounding items so that nothing is pinched or hindered otherwise. Remember that there are two different batteries for marine applications, reports Bass Pro Shops…
See more on northeastbattery.com

Considering Extra Power

  • A clever way to add extra power to your boat is with a dual-purpose battery. This product is different than the cranking or deep-cycle battery on your boat. The dual purpose product supports your marine accessories so that you can lower the strain and costs on the other batteries. Add these accessories to your extra battery, such as: 1. Fish finders 2. Fishing scales 3. Radios By re…
See more on northeastbattery.com

Prolonging The Battery’S Lifespan

  • Every deep cycle battery that you own can have a long life if you give it a full charge each time. The battery’s internal construction doesn’t respond well to short bursts of power. If you take the marine battery off the boat, the charging session should last between 14 and 16 hours, reports Battery University. This time period allows the battery to saturate with the electrical power so th…
See more on northeastbattery.com

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