Wednesday, July 17, 2024

What Size Boat Battery Do I Need

The Electrical Source: A Battery

What kind of Batteries do I need for my Boat? Marine batteries explained!

In a boat, electricity is stored in one or more batteries. ;The batteries are charged by your engines alternator or auxiliary battery charger. ;They can hold an enormous amount of energy, capable of pushing hundreds, or even a thousand amps so care must be taken, and proper circuit protection should not be ignored.

Greatly generalizing the topic here, but you usually run into two types of batteries in the size of boat we deal with:

  • Starting Battery; Has high current rush capacity
  • Deep Cycle Battery;Capable of deep discharge without harm
  • The;two setups we most often run into is:

  • Single Engine 1 starting, and 1 house battery
  • Twin Engine 2 starting, and 1 house battery
  • Every non-engine wire should be circuit protected with a fuse or circuit breaker

    Batteries have positive and negative. ;For current to flow a complete circuit must be made from positive back to the negative. ;Any break in the circuit anywhere will stop the load from operating .

    A normal battery might be able to push 800A or more current

    A normal battery might have 70-80AH of capacity. Meaning it can run a 1A load for 70 to 80 hours, or a 10A load for 7 to 8 hours before it is discharged.

    What Size Battery Is Best For My Boat

    Ok, its time to get a bit more technical. Lets dive deeper into some of the questions we mentioned above.

    What Types Of Batteries Do You Need?

    Your boat will need a cranking or starting battery to start its main engine. Youll also need a deep cycle battery to power your trolling motor and electronic accessories. Add another deep cycle battery if you have dual engines.

    Theres one more type of battery that can do both jobs: the dual purpose battery. But most experts agree this kind of battery doesnt do either job well. You should only choose dual purpose if your boat doesnt have enough space for more than one battery.

    How Much Amperage Do You Need?

    Its time to crunch the numbers! You might not enjoy mathematical equations, but trust usyoull enjoy your fishing trips much more if you calculate the AH you need to operate your vessel.

    Batteries have an Ah rating. This relates to the actual battery capacity. For example, a battery rated 100Ah delivers 5 amps for 20 hours, or 100 amps for one hour. But that may not always be true, since you shouldnt discharge batteries past 50 percent of their capacity .

    Carry out an Energy Audit and see what battery size will meet the energy demands of all your equipment.

    Heres a simplified energy audit method:

  • Use the formula W=AV. Transpose this formula to get the number of amps for a certain device.
  • Finally, add up the average amps per hour your equipment will use to find out how many amp hours your batteries need to cover.
  • Bci Battery Group Sizes

    Well start with a quick history lesson on what Battery Council International 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 1920s to promote the interests of the lead-acid battery industry . Through the years, BCI has developed technical standards that include size groups for common battery applications. To make them true drop-in replacements, we have sized our lithium batteries according to standard lead-acid group sizes.

    Although the BCI group size range is quite broad, including passenger car, electric vehicle, and commercial batteries, today well focus on sizes commonly used in marine applications. These include batteries that fall into Group 24, Group 27, Group 31, and 8D. BCI created group sizes to communicate a general standard for the maximum overall dimensions of a battery. 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 of the battery.

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    Hottest Faqs About Electric Outboard Motors

    A single post could not answer all questions about the electric outboards. Weve picked out the most frequently asked ones below with short answers.

    If you have any further confusion about the electric outboard motors, leave them in the comment and well get back to you asap and add yours to the list.

    #1. How rock proof are electric outboards?

    The electric outboard motor blade is usually made of solid materials and ePropulsion motors feature propeller collision emergency stop

    However, the rock or oyster bed could still possibly cause damage to the motor. If you are worried, you can always protect the outboard with some propeller guard.

    #2. What is the most powerful electric outboard motor?

    The most powerful electric outboard motor by far is 80 hp rated, and it is mostly for commercial use due to the high initial cost.

    #3. What size electric outboard do I need?

    To get the right size electric outboard motor, you need to consider the boat size , boatload, your desired speed, and the boating environment, etc.

    Generally speaking, a 1kw3hp electric outboard motor is enough to provide a satisfying speed and range for tenders, dinghies, and daysailers up to 1.5 tons, and 6kw10 hp electric outboard motor is for RIBs, fishing boats, and cruising sailboats up to 6 tons.

    Other Articles On Batteries

    Best Trolling Motor Battery (Updated: February 2021)

    Float phase: When the batterys acceptance declines to two to four percent of C, the voltage is reduced to 13.4 volts to maintain the battery without losing electrolyte from the cells. This is a maintenance phase, not a charging phase.

    Equalization: This stage is used to prevent flooded lead acid batteries from aging prematurely, and is an optional, frequently omitted phase. After the battery reaches the end of the acceptance phase, the battery continues to be charged at four percent of C until the voltage stops rising, usually around 15.5 to 16.2 volts. This forces the battery to its highest possible state of charge, boiling the electrolyte in a controlled manner and dissolving the lead sulfate crystals that have collected on the batterys plates.

    In industrial applications where maximum energy storage is important, this phase is done every charge cycle. In the marine environment, it is more likely to be done every 2050 cycles to extend the life and capacity of wet batteries. Gel and AGM batteries should not be equalized. Since electrical equipment and light bulbs can be damaged by high voltage, the battery should be disconnected from all loads during equalization.

    Recommended Reading: How To Remove Mold And Mildew From Vinyl Boat Seats

    Electric Outboard Motor For Boat: What You Need To Know

    The electric outboard motor is definitely appealing but the flooded information on the Internet could be overwhelming and get you lost especially if you are new to electric boating.

    Here I have rounded up the top 5 frequently asked questions so that you can easily decide whether to get an electric outboard motor for your boat.

    How Long Does It Take To Charge

    If you operate your house bank between a 50 percent and 85 percent state of charge, as many experts recommend, and charge once daily, you should be able to return the 35 percent of battery capacity by operating a properly-sized alternator for slightly over an hour. More deeply discharged batteries, or smaller alternators, will require more time. Surprisingly, using a massive charger or monster alternator to pour on the current can be counterproductive, and can shorten your battery life.; Excessive current makes batteries heat up and gas excessively . Soon the voltage limit is reached, causing a downshift from the Bulk to Acceptance Phase. Adding more battery capacity is a better solution, and may even decrease the needed recharging time. Bigger battery banks can accept more charging amps, so they replenish more quickly and you dont need to run your engine as long.

    Balmar’s Max Charge MC-612 Regulator has seven charging programs for your externally-regulated alternator.

    Read Also: What Is The Best Family Boat

    How To Rapidly Kill A Battery

    Undercharging: Consistently failing to fully recharge batteries leaves them with lead sulfate that hardens on their platesthey become sulfatedand gradually lose their ability to perform. Increased resistance when charging causes falsely elevated voltage readings, essentially fooling the battery charger, leading to further undercharging, in a downward spiral. Beyond a certain point, a sulfated battery cannot be returned to a healthy state, and you need a replacement. Keep your batteries charged, and equalize your wet cell batteries every six to eight weeks in temperate climates, and more frequently in the tropics.

    Overcharging: Especially fatal to Gel and AGM batteries, consistent overcharging boils the electrolyte out of the cells, and can even lead to thermal runaway, with the battery becoming hotter and hotter. One of our writers experienced thermal runaway on his liveaboard Catalina 30, caused by a ferroresonant dumb charger, with nearly catastrophic results.

    Excessive deep discharge: Dont completely discharge a deep cycle battery if it can be avoided. The deeper the discharge the less life you will get from the battery. The ideal method is to charge and discharge the batteries through the middle range of their capacity and, if they are flooded batteries, to equalize them periodically. Leaving the battery in a fully-discharged state, for example during winter storage, causes it to become sulfated.

    Cons Of Gel Cell Batteries:

    Tips – Choosing a Battery Charger for a Boat

    High initial cost; The gel cell battery is a specialty boat battery that costs twice as much as the best-flooded batteries. Although this cost lessens over time, because of its long-lasting deep-cycle uses. Anyways, entry costs are a factor for most buyers.

    Needs special chargers; You must use the correct charger on a gel cell battery or it will lead to poor performance and early failure. This means more money to spend for the boat owner.

    Overcharging sensitivity; This type of boat battery uses a special charger plus it charges at a lower voltage than other types. So, some boaters have a higher chance of high-voltage overcharging. The result is damage to the battery and is annoying to the owner.

    Poor heat resistance; Hot temperatures can create adverse effects to the electrolyte. As a result, this can turn the gel hard allowing it to shrink off from the plates. Exposing the plates will shorten the life expectancy of this boat battery.

    The Gel Cell Battery Pros:

    Deep Cycle applications; Gel cell batteries are excellent for deep cycle applications . They have a life expectancy of around 500 to 5000 cycles range.

    Vertical or horizontal orientation; Gel cells can operate in any orientation, although they may lose some capacity. They can even operate when a container cracks since these batteries dont leak. This feature is important to blue water sailors who experience survival storms. During this type of violent storm, a boat could roll upside-down so battery operation is critical. For these sailors heavy-duty battery restraints are necessary.

    No hands-on maintenance; For Gel cells, there is no maintenance after installation of the boat charging system. The sealed container means no electrolyte refilling is necessary. Which is great, as you dont need special safety gear on board to protect yourself.

    High vibration resistance; With a sealed container and the Gel technology, this type of boat battery is excellent in high vibrations. As well, they are spill proof.

    Minimal corrosion; Unlike unsealed batteries that are at risk of spills and damage, Gel cells stand up to corrosion. You can install one close to sensitive electronics since they wont damage or degrade like a Wet cell. A Gel cell is safe because there is less risk of sulfuric acid burns for unsealed batteries.

    Electric Outboard Motor Weight

    The electric outboard motor and battery weight could be a concern, especially for the elderly. Boating is enjoyable, but lugging the heavy batteries over boggy ground to get to a boat in remote areas is definitely not tempting.

    If you are looking for a portable electric outboard motor, consider the one with a built-in battery. The electric outboard motor with battery is easy to transport and could save you a lot of trouble.

    Some electric outboard motor batteries can even float in the water so there is no need to worry about dropping it while installing the outboard.

    Looking for a higher power electric outboard motor?

    It will need standalone batteries to power the electric outboard. If you are going this way, wed recommend looking at the E-Series LiFePO4 battery range.

    The E-series electric outboard motor batteries offer a modular system from 2kWh to 144kWh. They are very affordable marine-grade batteries with a long lifespan.

    Is There A Difference Between Deep Cycle And Marine Battery

    So what does deep cycle mean?

    Youve heard the term thrown around when talking about marine batteries. Youve probably also heard terms like starting, cranking, and dual purpose.

    Why should you care?

    All of these terms refer to different types of batteries that your boat may use.

    So no, there isnt exactly a difference between the terms deep cycle and marine battery. A deep cycle battery is a type of battery, and a deep cycle marine battery is a specific type of marine battery.

    Lets take a closer look at deep cycle, starting or cranking, and dual purpose batteries as they apply to marine batteries.

    Determine The Needs Of Your Boat

    What Size Battery Do I Need For My Boat? (Size Chart Added)

    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 boats 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.

    What Are The Dimensions Of A Marine Battery

    The dimensions of a marine battery refer to its length, height, and width.

    You might be wondering how to find the dimensions of your current marine battery. Is it fairly small or the largest your boat can handle?

    The battery dimensions are probably listed on the battery. If you cant find them, use a measuring tape to measure each side of the battery. This will give you the dimensions.

    Here are a few examples of marine battery dimensions:

    • 24M: 10 1/4 L, 6 13/16 W, 9 3/4 H
    • 27M: 12 1/2 L, 6 13/16 W, 9 3/4 H
    • 31M: 13 L, 6 13/16 W, 9 7/16 H

    Do I Need Multiple Batteries Formy Jon Boat

    There may be a case where youll be out on thewater without any energy or maybe you just need a little extra juice to keepyour jon boat moving along. Having multiple batteries for a jon boat can behelpful when you need it, which is why you may want to keep in mind having twobatteries on your jon boat.

    While it may seem like having an extra batteryon your jon boat makes sense because itll give you more power for your boat,youre most likely better off just getting a bigger battery. If you have a jonboat thats bigger than average and requires a strong supply of current to keepeverything powered, then it may mean youll need two batteries.

    If youve maxed out on battery size for yourlarge jon boat and you need more power, consider getting another battery thatyou can put in parallel to your existing battery. Before you do this, you needto make sure the specs of the batteries are similar, especially voltage, butthe amps can be different. By putting batteries in parallel, you canelectrically add the amps together to get even more energy to your jon boat.

    Types Of Marine Battery

    Choosing the right type of marine battery is going to be crucial for your boats performance, and when it comes to picking the right type, you also have to consider the chemistry of the power cell. Before you choose the battery for your boat, you have to keep in mind that the battery will handle two things; starting your boats engine and running all of its electrical load. Being aware of this aspect will make sure that the battery you are going to purchase will have the capability to provide every power that you need for your boat.

    • Smaller boats that need enough power for both starting their engine and running their electrical loads from a stand-alone battery.
    • They are also suitable for sailboats with two interchangeable batteries for powering electrical loads.
    • Dual purpose batteries can a be a good replacement battery for boats that need enough power for their electrical load and starting their engine compared to starting batteries.

    Those are the different types of batteries that you can choose from. You have to keep in mind that selecting the right type of battery is going to be crucial for your boats performance. Now you have to learn about the different types of battery chemistry to make sure that you are going to pick the best suitable battery for your needs.

    The Abcs Of Marine Batteries


    You need to know the differences between battery types before you can pick the right setup for your boat.

    I;recently received an e-mail from a reader who said that while he liked this column and looked forward to it every month, he also viewed it with trepidation because every time he finished one task he found he had more things to add to his to-do list. For his benefit and that of other harried readers I offer this column as a Christmas present. I promise it will be informational only and contain no maintenance tasks whatsoever.

    The subject is marine batteries. This may not seem terribly exciting at first glance. Most of us give little thought to our batteries until they dont work. Fortunately thats rare. Marine batteries are remarkably durable and reliable, but like old soldiers, they eventually fade away. When they do, knowing some battery basics can help you pick the best replacement.

    A batterys ability to crank an engine is indicated by its cold cranking amps , the amount of juice delivered at a specific temperature, usually 32 degrees Fahrenheit. Since few pleasure boats operate near freezing, CCA is valuable mainly for comparison, and most people just use the amp-hour rating. Diesel engines require batteries with more amp-hours because they have much higher compression ratios, which make them harder to crank.;

    This article originally appeared in the December 2014 issue of Power & Motoryacht magazine.

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