Best Deep Cycle Marine Batteries : Tested!


Sure, you may have all the latest and greatest fishing gear and gadgets, but without a reliable battery to power your boat, you’ll be up a creek without a paddle (literally).

Now, I know what you’re thinking. “Bill, how do I even begin to choose the right marine battery for my needs?” Trust me, I’ve been there. It can be overwhelming to navigate the sea of options out there and decipher all the technical jargon.

But fear not, my fishing friends, because I’ve done the legwork for you. I’ve scoured the market and put together a list of the top-rated marine batteries that will keep your boat cruising all day long.

And don’t worry about getting bamboozled by sneaky manufacturers making grandiose claims. I’ll give you the inside scoop on what really matters when it comes to selecting the right battery.

So, whether you’re a seasoned angler or just starting out, buckle up and get ready to learn everything you need to know about choosing the perfect deep cycle marine battery. Let’s dive in, shall we?

Here’s My Top Pick

Let me tell you about the holy grail of deep cycle marine batteries. This beauty is not only a champ when it comes to recharging methods and times, but it’s also the most reliable and performance-oriented battery out there.

Trust me, I’ve tested them all and this one reigns supreme. It’s the LeBron James of marine batteries, the Tom Brady of deep cycle power, the Beyonce of boat juice.

So if you want to leave your fishing buddies in the wake of your superior battery power, look no further. This bad boy is the cream of the crop, the top dog, the big kahuna.

Table of Contents

Why We Need Marine Grade Battery?

Face it, the most important thing you can have on your boat is a deep cycle marine battery. Why?

Because they help to start engines a lot easier by augmenting the amount of powering chances and preserving energy much more efficiently – cells are a must.

A deep-cycle battery is designed to provide a much more efficient surge of power that will start an engine.

Contrarily, less efficient but more powerful surge of energy from ordinary engine-starting batteries can drain out of power in just a few unsuccessful starts.

A starting battery, on the other hand, is also very efficient in providing great sustained loads of power while trying to start a 12v system.

However, this one works better for engines than for entire systems, making them much more useful at the time of getting the boat ready to keep navigating.

These are both the types of marine batteries you can pick, and almost all of them are pretty similar to each other while some can offer both performances at the same time.

Now, let’s see our top 3 pick for deep cycle marine battery.

Top Pick
OPTIMA Batteries OPT8016-103 D34M BlueTop Starting and Deep Cycle Marine Battery
Best Cheap
VMAX857 AGM Battery 12 Volt 35AH Marine Deep Cycle HI Performance Battery ideal for boats and...
Premium Choice
Odyssey 34M-PC1500ST TROLLING Thunder Marine Dual Purpose Battery
Battery Name
Optima BlueTop D34M
VMAX V35-857
Odyssey 34M-PC1500ST
Our Rating
4.9 / 5
4.3 / 5
4.5 / 5
Top Pick
OPTIMA Batteries OPT8016-103 D34M BlueTop Starting and Deep Cycle Marine Battery
Battery Name
Optima BlueTop D34M
Our Rating
4.9 / 5
Best Cheap
VMAX857 AGM Battery 12 Volt 35AH Marine Deep Cycle HI Performance Battery ideal for boats and...
Battery Name
VMAX V35-857
Our Rating
4.3 / 5
Premium Choice
Odyssey 34M-PC1500ST TROLLING Thunder Marine Dual Purpose Battery
Battery Name
Odyssey 34M-PC1500ST
Our Rating
4.5 / 5

Best Deep Cycle Marine Battery for the Money

1. Optima BlueTop D34M Starting and Marine Battery

The BlueTop marine starting battery from Optima is an outstanding addition to any boat, not only for its excellence in recharging methods and times, but because it is a lot more reliable and performance-oriented.

It works exceptionally well for electronic systems, trolling motors, and even RVs, and other similar 12v vehicles.

The unit is effortlessly one of the most flexible, versatile and yet reliable starting and deep-cycle batteries in the market.

Outstanding Power & Strength

At 12v with 750 cold-cranking AMPs, the OPTIMA BlueTop will quickly turn any engine on.

Even the largest of boat engines or RV motors, this battery will give its great to provide a first-touch ignition that no other cell is capable of.

Even in bad weather, the starting will be faster and more effective than most cells out there.

Durable & Reliable Construction

You can mount the Optima BlueStop practically anywhere without having to worry about its functionality or integrity.

It is designed to support up to fifteen times more vibration while delivering 120 minutes of constant performance and providing three times more charges than ordinary batteries.

Also, it is spill-proof and demands almost no maintenance at all.

Top-Notch SpiralCell Tech

When looking at the interior of the Optima BlueStop battery, you can see a unique manufacturing method for its lead plates and oxide, which deliver better performance and durability.

All of this is done with spiral winding lead plates that maintain better tolerances, humidity, temperatures and eventually get every process done more efficiently.


  • Exceptional strength and power charge: will turn any engine on.
  • Fantastic construction for a long-lasting and reliable experience.
  • Much more efficient & resistant in the long run.
  • Excellent spiral cell technology: more efficient performance from the inside.


  • Not the best one-stand durability out there, as it only offers up to 4 hours of continuous trolling with normal-sized 12v boat engines.

2. VMAX857 AGM Marine Battery ideal for boats and 18-35 lb minn kota, minnkota, cobra, sevylor and other motor [Best Marine Battery for The Money]

We loved virtually everything about this one, from the way that sturdy handle is designed to the unit’s shiny black color.

With the VMAX857 marine battery, you never have to worry about checking the particular gravity of the electrolyte or adding water to the battery tanks. The unit is virtually free of maintenance, and thus a perfect selection for those seeking this kind of convenience.

The chemical and physical structure of the battery’s plates is quite unique.

Unlike other Pb-Ca plates that other batteries utilize, the VMAX plates are designed with superior features that boost the resistance against shock & vibration and improve the general performance of the battery.

The AGM absorbs the electrolyte totally, and hence, there’s no spillage and subsequently no chemical hazard.

People that have used this battery will probably tell you about its amazing lifespan, but an even more wonderful aspect is the battery’s ability to recover after a deep discharge.

So, I think this is one of the best value marine battery.

Highlighted features:

  • 35 AH deep cycle battery
  • Superior resistance to shock and vibration
  • No spill or chemical hazard
  • Elegant design
  • Handy handle

3. Optima Batteries 8040-218 D35 Dual Purpose Battery, Yellow-Top

Need a marine battery with adequate power for starting your outboard motor as well as running the various accessories in your boat? The Optima Batteries 8040-218 D35 Yellow-Top could be just what you’re looking for.

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With a CCA rating of 650 (cold cranking amps), and a reserve capacity of 98 minutes, this battery is truly deep-cycle, providing you with the power you need out in the sea.

Worried about the durability? Don’t be; the battery employs 99.9% lead cells with spiralcell technology for an improved battery life with many cycles.

Actually, we have found this battery to have almost twice the number of cycles as most other batteries.

But, don’t forget, lifespan is also dependent on the way you handle the battery.Another benefit has to with resistance.

You might already know how rough the sea can be with all sorts of tides; that’s why you need a battery like the Optima Batteries 8040-218 D35 Yellow-Top, which is designed with a thick plastic exterior to absorb shock.

The Optima Batteries 8040-218 D35 Yellow-Top is for those who need a compact solution for their need to save space.

The battery has a weight of around 36 lbs and with a length of less than ten inches, making storage and mounting easy and convenient.

Highlighted features:

  • Doesn’t require much maintenance
  • Spiral-cell technology for durability and efficiency at saving power
  • AGM technology with excellent performance
  • Relatively lightweight
  • Multipurpose – cranking the motor and running accessories
  • 650 CCA and 98 reserve capacity

4. Mighty Max ML35-12 Light Marine Battery Sevylor Minn Kota

Mighty Max Battery 12v 35ah Light trolling Motor Battery sevylor minn kota Golf cart
  • ML35-12 SLA is a 12V 35AH Sealed Lead Acid (SLA) rechargeable maintenance free battery – UL Certified
  • Dimensions: 7.76 inches x 5.12 inches x 7.01 inches. Listing is for the Battery and Screws only. No wire harness or mounting accessories included.
  • SLA / AGM spill proof battery has a characteristic of high discharge rate, wide operating temperatures, long service life and deep discharge recover.
  • Rechargeable battery that can be mounted in any position, resists shocks and vibration. Long lasting high performance in high and low temperatures.
  • Backed by a 30 day refund policy and full 1 year warranty.

Maybe you want a marine battery for small boats or fast applications, the MinnKota Light-Trolling will quickly get you wherever you want as long as you use correctly.

It works better as a replacement battery for when your main one doesn’t want to work, but thanks to its excellent construction and overall performance, you will obtain a cell that starts any engine without problems, especially those who need a small device like this.

Small but Effective Battery

At 12v and 35Ah reserve capacity, the Mighty Max MinnKota motor battery is capable of delivering outstanding performances at all times.

It works both as a starting and as a deep-cycle battery, helping you to start engines or maintain electronic systems on at all times.

It is entirely well-made, and even for its small design, you will receive top-notch performance.

Entirely Well-Constructed

With an SLA and AGM spill-proof design and one of the good discharges rates in the market, this device will take you anywhere you want without problems, as it resists shocks, vibration and even holds during very hot or cold environments.

Very Convenient Design

At only 7.68 height, 5.16 inches wide and 7.13 inches long, this battery is tiny, so it fits practically anywhere.

You will be able to start your small boat without having to worry about anything, much less where to put your battery as it doesn’t only looks tiny it also weighs roughly 23lbs which will come increasingly convenient for anyone.


  • One of the most long-lasting, resistant and reliable batteries in the market.
  • Small but incredibly well-made entirely.
  • Much more convenient design: smaller and much less heavy.
  • Will provide up to 35ah which can start up any small engine.


  • It won’t be possible to use this battery with large boats, as it doesn’t offer enough amperage to hold most engines or electronic systems, yet it can work for at least a few short hours as a replacement battery.

5. Optima 34M BlueTop [Best Marine Starting Battery]

OPTIMA Batteries 8006-006 34M BlueTop Marine Starting Battery
  • 12-Volt, 800 Cold Cranking Amps, Size: 10″ x 6 7/8″ x 7 13/16″ tall, Weight: 38.4 pounds, Dual SAE & 5/16″ Stainless Steel Stud Posts

If you look for marine starter battery, then the Optima 34M BlueTop will surely fit your needs entirely.

What makes it so attention-grabbing is its ability to provide a cranking and a deep-cycle performance, which allow you to rely on its reserve capacity without having to worry about anything.

It is also incredibly small and much more reliable than most.

Strong but Small

Capable of delivering up to 800 cranking amps, this battery will undoubtedly start up any engine you pair it up with.

This means you can get even during the hardest of situations a very reliable performance, despite being smaller than other options and fitting practically anywhere you want.

More Steady and Constant

The Optima 34M BlueTop battery is excellent just because it can hold 100 minutes of constant use without breaking a sweat.

This starting power is even reliable during the hardest of weathers, thanks to the 15x more resistant construction that holds during hard vibrations.

Superb Construction

Alongside the SpiralCell technology and the 3x recharging reserve capacity, using the BlueTop 34M from Optima is like using an excellently-made device with the whole purpose of providing more durability, reliability, and total performance.

It works well in any boat or RV you use it with, and will quickly reach eight years of usage without worries.


  • Really strong, versatile battery for its size.
  • Excellent construction for superior durability and performance.
  • Steady and constant performance: much more reliable.
  • Top-notch design for a much better experience.


  • It won’t work for deep-cycle applications as good as other dual-purpose or deep-cycle batteries as it is not correctly made for that.

6. Odyssey 34M-PC1500ST TROLLING Thunder Marine Dual Purpose Battery

Odyssey 34M-PC1500ST TROLLING Thunder Marine Dual Purpose Battery
  • Cold Crank Amp (CCA)- 880; Better : Limited 3 and 4 year full replacement – not pro rata; Longer service life: 3-10 years of service life; save consumers time, money and aggravation; Longer cycle life
  • Longer shelf life: Can be stored on open circuit without the need for recharging up to 2 years or 12. 00V, whichever occurs first; Recharge: Highest recharge efficiency of any sealed lead battery on…
  • Vibration resistance- design protects against high impact shock and mechanical vibration; Extreme temperature tolerant- Operating temperatures from -40degree Celsius (-40 degree Fahrenheit) to 80…
  • Totally maintenance free: No need to add water, ever Improved safety- US Department of Transportation classified as a non-spill able battery; No acid spills, no escaping gases; Totally dry AGM design…

The Odyssey 34M-PC1500ST is a best dual purpose marine battery that prides the great recharge efficiency among the seal lead acid batteries. You can store it for two years without having to recharge it.

It also has a quite lucrative warranty – a limited three and four-year warranty that enables you to get a free replacement if the battery develops an issue within that timeframe (based on the conditions for replacement).

Another aspect that makes the Odyssey 34M-PC1500ST a top choice is the length of its service life – three to ten years (the better the maintenance the longer the life). This saves you money and time.

Tips: don’t ever let a battery sit in a discharged state. Keep it charged and its life is sure to be long.

The cold cranking amps (CCA) rating is also good, at 880.

Keeping in mind that there are batteries out there with as little as 300, 880 is pretty high. Always check your engine’s CCA requirements before getting a battery; you want to ensure the battery can crank the engine when the temperatures are low.

The Odyssey 34M-PC1500ST’s vibration resistance is also good. The battery uses a sturdy design to protect the vital internal parts from damage from vibration and impact shock.

The Odyssey 34M-PC1500ST is a bit pricey but here’s our advice: don’t skimp on a boat battery and you’ll almost never get stranded out in the sea.

Highlighted features:

  • Exceptional temperature tolerance – from -40 °F to 176 °F.
  • Vibration and shock resistance
  • Maintenance free – you don’t have to keep adding water
  • Spill-proof
  • No dangerous fumes

7. Sealed Lead Acid (AGM) Deep Cycle Battery – DCM0035 replacement battery

Interstate Batteries 12V 35AH Sealed Lead Acid (SLA) AGM Deep Cycle Battery (DCM0035) Insert…
  • DEEP CYCLE MOBILITY BATTERY: Interstate Batteries DCM0035 professional-grade, high-quality battery developed specifically for electric wheelchair’s, electric scooter’s and more. Longer life & more…
  • DCM0035 BATTERY REPLACEMENTS: Download the Compatibility Guide below under Product Guides & Documents to see some devices this battery powers. ABEC WHEELCHAIRS, BEST TECHNOLOGIES, BURKE, DAMACO…
  • RECHARGEABLE, MAINTENANCE-FREE, SPILL-PROOF: Rechargeable, maintenance-free, & spill-proof because of the AGM & VRLA technology (valve regulated) that eliminates spills & overpressure. 12 Volt, 35 Amp…
  • HIGH-QUALITY, HIGH-PERFORMANCE BATTERY: No other brand puts their products through more rigorous testing than Interstate Batteries 7-Point Quality Protocol. We don’t meet industry standards – we…
  • MOST TRUSTWORTHY POWER SOURCE: For 70+ years, Interstate Batteries purpose has been to deliver the most Outrageously Dependable source of power to the world. Our customers come first, so we strive to…

The aspect we noted most about is this battery is that it’s quite lightweight compared to most other marine batteries.

Weighing in at 23.1 pounds, and with a length of just about 7 inches, the battery is most definitely an ideal choice for those who are looking to save space or someone who doesn’t like lifting heavy items.

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If you’re looking for a fair-priced battery that delivers excellently for a long time, then this sealed lead acid battery will be a good pick.

It is a non-lithium battery with a long lifespan and a reliable power output. And that’s not all; you can use the battery for various applications in the sea, in the garden for your agricultural needs, and even on the road to run various applications in the vehicle.

The battery will work well both as a starting battery and a deep cycle battery.

You know why it’s referred to as a sealed lead acid battery? It’s because the battery is totally sealed such that the liquids inside won’t leaked in case the battery is tipped.

It also means that you don’t need to keep adding water for the battery to work. The acid is reabsorbed by the battery’s elements that are part of the AGM.

For the fast recharge time, the good reserve capacity and the ability to store the battery in tight compartments, as well as many other benefits, we’d say go for it!Highlighted features:

  • Lightweight and ideal for squeezed compartments
  • Fast recharge
  • Spill-proof
  • Multi-purpose
  • No release of dangers vapors
  • Good power output for cranking and running electronics

8. Marine Battery Accessories: MinnKota Trolling Motor Power Center

Minn Kota 1820175 Trolling Motor Marine Battery Power Center
  • This battery box / power center contains easy access external battery terminals that allow trolling motor leads and charger leads to be connected to the battery posts without opening the box
  • Protects your battery (not included) on a small boat, transom application (boats that do not have battery compartments)
  • Built-in, push button battery meter with 4 LEDs displays current “state of charge”
  • Two 12-volt accessory plugs
  • 60A resettable circuit breaker connected to top

Before we continue discussing the types of batteries available, we thought we’d tell you about a very special piece of equipment that goes hand in hand with a deep cycle marine battery – a battery box.

Did you know that the way you store your battery determines how long its useful life will be? That is why storage is very important, and in that regard, the MinnKota Trolling Motor Power Center is one of the good battery storages out there for 24 and 27-size marine batteries.

Here’s why:

  • It is pretty sturdy – it’s built from hard materials that are not easy to break. The handle is also pretty robust.
  • It has easily-accessible battery terminals where you can attach the battery leads on the inside. That means that you get to connect the cable plugs without opening the battery box. Isn’t that convenient?
  • It’s installed with a battery meter that shows you the present state of the charge.
  • Comes with some circuit breakers that you can reset manually. You can either set it to 15 amps for accessories like the refrigerator and the lights or to 60 amps for the trolling motor.

If your boat doesn’t have a battery compartment, or if the compartment is not holding the battery as you’d like it to, it’s time to get the MinnKota Trolling Motor Power Center. This battery holder is also very useful for inflatable rafts.

The only issue with this battery is that the strap doesn’t stay very tight, but you can modify it, right?

Highlighted features:

  • Manual circuit breakers
  • External battery terminals
  • Built-in battery meter
  • Sturdy body and handle

Marine Boat Batteries What to look for?

What to Look before Buying a Marine Boat Battery?

Types of Marine Batteries

When it comes to marine starting batteries, you will have three main categories that will make all the difference between having the right one or the wrong one for your boat.

Here you will find the deep-cycle battery, the starting or cranking battery, and the dual-purpose one.

The deep-cycle battery is the one we take on this article, and it is the one that does its highest energy to provide enough energy and power to an electronic system or device within a boat.

As you know, an engine of a ship only powers up its motor and sometimes the electronic system is not linked to the motor, so you need an additional battery to start it up.

That’s where a deep-cycle battery enters into work.

Then you have the starting or cranking battery which primary purpose is to ignite the motor of a boat and regularly makes sure that you can navigate and go full or slow throttle according to its construction and design.

These, in contrast with deep cycle marine batteries, do not work for electronic systems or other devices.

Finally, you can find the dual purpose batteries which offer both the chance to ignite engines and at the same time cycle entire systems without problems.

These are often more expensive and heavy. Plus, they are more versatile and flexible but do not deliver the same energy strength as starting or deep-cycle batteries for single performances.

If you are needing a battery for only cycles that maintain your electronic systems working, go for a deep-cycle battery.

Otherwise, in case you only need it for starting the engine, then a cranking battery will fit your needs.

Or else, a dual purpose battery would be great, as long as you know that it won’t deliver the same strength as a normal cranking or deep-cycle battery.

AGM or Cell Batteries

Another essential part of batteries is how they are made.

This is precisely where the magic happens, how the electrolytes do their work and how the conducting medium creates the energy and sends it to the engine or system.

And there are two to pick here;

  • AGM design
  • Cell design

The cell design is the type of dual purpose battery that contains a mix of sulfuric acid and water, sometimes made with lead or other similar liquids.

This is the most popular of all deep cycle batteries and works both for deep-cycle and starting batteries, yet they deliver superior cycles of discharge and charge, which make them slightly more fitting for deep-cycle designs.

These batteries also hold the use much more efficiently and usually weigh even half of what the best AGM marine battery do.

But this is all translated into a dual purpose battery that demands more maintenance and may spill acid when not used or handled correctly.

AGM marine batteries are the deep cycle batteries that are made with an absorbent glass matting (AGM) that goes between the lead plates.

This matting has electrolyte acid which allows oxygen and hydrogen to refill the dual purpose battery automatically, making maintenance almost unnecessary.

It makes them be built wholly sealed, which also avoids acid spilling and other accidents, even when used in different angles or places.

They are often incredibly resistant as well.

But, you won’t be able to discharge the deep cycle marine starting battery when it has been overcharged, and they usually weigh a lot more and sometimes cost even double of a cell dual purpose battery.

Here, it is recommended that you go for something that doesn’t eventually become uncomfortable.

You need to consider the weight and the size, where the AGM batteries are often much bigger and heavier and the cell batteries smaller and lighter.

If you have little space on your boat, go for a cell battery, otherwise, go for an AGM battery if you want superior reliability.

Amperage Per Hour (Ah)

The amperage is the total energy in AMPs the dual purpose battery will be able to deliver each hour when following the C-20 rating.

This means that a deep cycle marine starting battery that offers 35 Ah, in C-20 grade it says that it can provide up to 35 Ah throughout a 20-hour period, it would mean 1.75 AMPs each hour which is enough for a simple electrical device such as a control board.

For a battery with 150Ah and a C-20 rating, you would be receiving 17.5 AMPs per hour, which is enough to power up a TV or any boat-related device of the same size.

However, all these measurements can be misleading, as there are also C-100 and C-6 ratings out there, which are measured in 100 and 6 hours of functioning accordingly.

So you will have to choose very carefully when buying, so you buy something that offers enough amperage for your boat.

Especially in deep cycle batteries, the Ah rating can make the total difference between a deficient and a top-notch product.

Boat battery size

Replacing an old deep cycle marine starting battery? It’s essential that you ensure the one you’re getting will fit in the box.

There are different battery sizes, like 27, 31, 6D, and more.

The task is to get a deep cycle marine battery that is suited for the available space but bear in mind that the size of the marine starting battery also determines the power holding reserve battery capacity and the output.

Different Types of Marine Batteries

There are 3 main types of deep cycle marine batteries. These are:

  • Flooded batteries
  • Absorbent glass mat
  • Gel batteries

1. Flooded Batteries

Otherwise known as the wet marine batteries, the flooded deep cycle batteries are the most common variety and they are also the most inexpensive ones.

As the dual purpose battery charges, the acid inside (sulfuric) gives off hydrogen and oxygen, which get discharged via the vents.

Although these batteries might be a good choice for someone on a budget, they’re not the best option if you’re looking for high quality.

First, you need to inspect them from time to time and fill them up with distilled water. Then, their self-discharge rate (6 to 7 percent) that is higher than that of other types of batteries.

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Another problem is with the maintenance, as the deep cycle batteries are unable to tolerate high vibrations and you need to keep the batteries upright always.

2. Gel Batteries

Gel deep cycle batteries use a blend of fumed silica, pure water, and sulfuric and phosphoric acid.

With this kind of dual purpose battery, maintenance is not very hard; you don’t have to keep the dual purpose battery upright.

The gel is viscous, and this prevents leakage even when the deep cycle battery is not upright.

Also, you don’t need to keep adding water, as the oxygen and hydrogen produced as the deep cycle battery charges gets changed back into the water.

3. Absorbed Glass Mat (AGM) Dual Purpose Battery

AGM batteries are fitted with glass mat separators, which soaked in an electrolyte-acid solution.

With these deep cycle batteries, you don’t have to worry about refilling with water, as the oxygen and hydrogen recombine to form water.

Another advantage with these batteries is that they have a high tolerance to shock & vibration, so you don’t have to worry about sailing in rough waters.

Even though AGM batteries will require you to dig deeper into your pockets, the quality is unmatched.

Deep cycle marine battery Tips

A deep cycle marine starting battery is arguably the heart of your motorboat, as it powers the vessel’s electrical system.

Many accessories in the boat, including the lights, the radio, the anchor, the GPS, and the GPS, rely on the proper working of the deep cycle marine starting battery.

As such, it is very important that you take care of the deep cycle battery, and below, we have discussed a few boat battery maintenance tips that you might find helpful.

1. Get one that is sufficient 

This one might not be exactly about deep cycle marine starting battery maintenance, though it’s pretty important if you want a battery that works for you.

Before going out there to purchase a deep cycle battery, consider all the power needs in the boat. Be sure to get a marine battery that provides more 10 percent power that what is required.

2. Give it some cool of time 

The discharge-recharge cycle produces heat in the marine battery system. Thus, after you charge the battery, it’s advisable that you give it some time to cool off.

3. Charge less during the early days

A new dual purpose battery ought to charge around 20 percent below the full reserve battery capacity till the plate formation process is complete.

4. Avoid charging it wet

According to experts, you shouldn’t attempt to wet charge your deep cycle battery with a sealed battery charger. A wet battery needs high voltage, else it will not charge fully. And the results? Battery corrosion.

5. Use a voltmeter

It’s important that you test the performance as well the present state of the battery.

A voltmeter facilitates taking the volt reading, and you could also use it for load testing.

Daily maintenance:

  • Recharge the marine battery as soon as possible because if you allow it to remain in the discharged state too long, the battery’s charge reserve battery capacity could deteriorate.
  • Ensure that the level of the electrolyte is below the split ring’s splash barrel. Use only deionized or distilled water for refill.
  • Clean all the connectors, including the terminals and the cable connectors as often as you can.
  • Keep the battery’s upper surface free of moisture.

The Elements of a Good Deep Cycle Marine Battery

You probably know that the deep cycle marine batteries are available in different types, sizes, prices, and features.

With all these elements to consider, you might have a hard time looking for the marine battery that truly suits you.

So, in this section, we’re going to examine a few elements you should look for to get the best boat battery reviews including type of battery.

1. The use

Are you intending to use the deep cycle marine battery for kickstarting the boat or running appliances on the boat or for both objectives? Knowing precisely what you will use it for helps you know the starting power suitability as well.

The starting power suitability refers to the measurement of the amp hours delivered by a lead-acid battery for 30 seconds at 32°F, so the output is or at above 7.2volts (the minimum power needed for kick starting the engine). The units used are cold cranking amps (or CCA).

If you’ll ever crank the engine during a cold season, be sure to get a deep cycle marine battery that meets your boat’s CCA requirements.

2. Maintenance

Older deep cycle marine batteries require higher levels of maintenance, which can be quite boring. Therefore, consider getting a new AGM battery, which needs very little maintenance.

Flooded and gel deep cycle marine batteries needs more maintenance. Although most type of battery requires at least some maintenance.

3. The date of manufacture

Even a new, unused battery loses effectiveness and fails to keep the charge as times moves by.

A battery that is just from the factory performs better than one that was manufactured a year ago, even if it has remained unused.

So manufacturing date is something you need to keep in mind.

How to Use and Setup Deep Cycle Marine Battery Properly?

How to Use and Setup Marine Battery Properly

It might seem like a daunting task to install a boat battery, but you’ll find that the process is not as difficult.

If you’ve installed a car battery, then you will find this easy, as the process is virtually the same.

Don’t fret if you haven’t installed a car battery we’ll be sure to simplify the process as much as possible.

Before installing the battery

Before you install the battery, there are a few matters you got to keep in mind. The most important one is about safety.

Bear in mind that you’re working with an electrical system, and thus there’s potential risk involved. Therefore, be very careful and make sure the connections are right.

Another thing to consider is the battery box – you need a good one for protecting the battery even in rough waters.

Tools – get 2 wrenches: a 1 ½ inch and 9/16 inch.

These 2 will help in removing the existing connections and installing the new ones. Get some grease also, for the new battery terminals.

The Steps for Battery Installation

  1. In case you are replacing an existing battery, remove it first. Turn the battery switch off and then use the wrenches to remove it by disconnecting the cables then lifting it from the box and placing it out of the way.
  2. Get the new battery and check to ensure that its cables are well aligned with the terminals. Place the new battery inside the box and ensure it’s held securely.
  3. Before re-connecting the cables, apply some grease to the terminals; you can use Vaseline. The purpose of the grease is to make the connection strong and reliable.
  4. Reattach the cables, starting with the positive terminal, then the negative one. As soon as the connections are made, get any loose cables out of the way, so they don’t end up catching on the box’s lid.
  5. Use the wrenches to wrenches to make the cable connections on the terminals secure but don’t tighten them too much just ensure the connection is sturdy enough and unlikely to come off accidentally.
  6. Restore the battery box’s lid.

After installing the new battery, it’s time to test it. Here’s how to do that:

Turn on the battery switch or switch to the right battery number if there’s more than 1 battery being used.

To see if the battery is actually working, turn on any appliance on the boat that relies on the battery for power, like the GPS or the lights.

Also, try starting the outboard/inboard motor. If there are issues, it could be that the connections are not made properly, so check them.

The Benefits of Using Deep Cycle Marine Battery

Especially in summary, a deep cell cycle marine battery is designed to take care of all the functions it’s needed for on the boat, and it may be used to supply power to a number of appliances, like the refrigerator and the radios, but a car battery is meant largely for the cranking (starting) process, and thus it would be insufficient for your marine needs.

Again, the design also matters. Marine batteries are normally designed to withstand more unfavorable conditions, like shock from the rough waters.

The main difference between marine batteries and car batteries is the discharge ability.

Car batteries are referred to as marine cranking batteries. They’re able to discharge lots of current quickly but for a limited duration.

In contrast, marine batteries are designed to take care of a number of functions, and that is why you’ll hear them being called house batteries.

Apart from cranking the engine, these batteries keep supplying power to the electrical system.

Marine batteries don’t just supply lots of power during cranking; they’re capable of supplying power for an extended duration.

They provide energy to a number of systems and appliances on the vessel, including the lighting, the sound, the pumps, and more.

What makes the marine batteries able to do this is its construction and design.

The plates used in marine batteries are thicker than typical, thus increasing the power holding reserve capacity.

Another advantage of marine batteries over car batteries is that they’re designed with features for sturdiness so they can be able to withstand hostile conditions.

They, typically, have higher shock-absorbing reserve capacity than car batteries.

Tips to Get the Best Performance from Your Marine Battery

When Should You Replace Your boat Battery?

Many sources say that when using it regularly, a lead-acid deep cycle marine battery will serve you for two to three years, but there’s actually no standard answer to this question.

The lifespan of your battery will depend largely on how you use and maintain it.

If you use the battery as recommended by the manufacturer and follow the maintenance guidelines we’ve discussed above, then you can expect the battery to function flawlessly for 5 seasons.

Another important determining factor for the lifespan of the battery is its type, and of course, an AGM battery will last longer than a flooded or gel type.


Here are the most frequently asked questions regarding marine batteries, and we’re positive that by going through them, you will learn a thing or two about these batteries that will prove to be very helpful.

1. What is the standard lifespan of a deep cycle marine battery?

A marine starting battery can last between 6 to 8 years if it is heavily used and up to 10 years if it is used not demandingly.

Now, an AGM deep-cycle battery is capable of going up to 8 years. A cell battery, on the other hand, can offer five years of regular use, going up to 8 years if lucky.

2. Can you use a deep-cycle battery for starting power supply?

Yes. Deep cycling batteries are not exactly made for starting power supply as they offer less cranking AMPs, yet they can be used without problems as long as they meet the vehicle or appliance amperage needs.

3. What is the average temperature to work with a deep cycle marine battery?

There’s no exact temperature for a battery to work correctly. But it is known that batteries last longer in warm environments (70ºF to 100ºF) than they do in cold climates (-20ºF to 50ºF) in which they would drain a lot faster due to the changing internal composition.

4. Can I use a marine deep-cycle or starting battery for my RV?

Yes, totally. However, you must make sure that it offers enough cranking or hour amperage according to your needs.

RVs, for example, often demand much more amperage than boats due to the different appliances they boast.

5. Do I need more than 1 battery?

You will need at least a starter battery and a deep cycle battery for powering up devices.

If you need a battery for both powering up appliances and starting the engine but you have limited room on your boat that a single battery space is available, then you can go for a dual purpose deep cycle marine battery.

6. What type of battery do I need for my boat or vessel?

Deep cycle marine batteries.

7. Can a deep cycle battery start an engine?

Theoretically yes. But it will damage the battery because it’s not designed for that.

8. Is there a difference between deep cycle and marine battery?

Marine Starting Batteries provide powerful spurts of energy for short time and deep cycle battery provide balanced power for longer time.

9. How long do marine deep cycle batteries last?

Marine Battery lasts 1-6 years. AGM Deep cycle battery lasts 4-7 years. Gel Cell Deep Cycle lasts 2-5 years. Flooded Lead Acid Deep Cycle Battery lasts 4-8 years.

10. What is the best deep cycle marine battery for the money?

VMAX857 battery is the one.

11. Can you overcharge a marine battery?

No. It will damage the battery.

12. How often should I charge my marine battery?

charge it every 30 days.

13. Can you use a trickle charger on a marine battery?

Yes, trickle charger works for marine battery.

Anchor Down and Power Up: Choosing the Perfect Deep Cycle Marine Battery

So, ready to pick the best deep cycle marine battery now?

Don’t waste more of your time and start making the right choice to prepare your boat for the next fishing season or if you want to start getting into deep sea with reliable equipment.

The batteries we presented to you before will surely meet all of your needs completely.

You just have to make assured that you choose the right battery that fits with what you’re looking for and what your boat eventually needs.

Happy boating!

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