Best Deep Cycle Marine Battery Reviews for 2020 (Updated)
It’s the time of the year when everyone is checking on their boats and equipment, the fishing season is arriving, and you want to be prepared for it too. Right?
Apart from the fishing tackles and overall tools to make your fishing experience better, there’s always a need to have your boat ready to take on long days on the deep sea.
And what is better to prepare your boat than having a deep cycle marine battery?
Now, selecting the best marine deep cycle battery isn’t a piece of cake; you have to do lots of research, and you can’t always trust what the manufacturers say.
That is why we’re here. Today, we will review the top-rated marine batteries that you can find easily on the market and give you lots of tips on choosing the right model.
Let’s start, shall we?
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 14 Best Deep Cycle Marine Batteries Review 2020
1. Vmaxtanks SLR-125 AGM Deep Cycle Rechargeable Battery
Capable of delivering more than ten years of constant use, this one is a top-notch performer for anyone who expects not the most versatile or flexible of performance but non-stop incredible reliability throughout the years.
Made with superior quality construction, it will help you start any 12v electronic system without problems, making your boat travels a lot more peaceful.
High-Grade Construction Quality
The AGM Deep Cycle battery from Vmaxtanks is not a simple battery in the inside or the outside.
It provides a top-notch heavy-duty construction that stands any weather to enjoy its performance even in the harshest of environments or situations.
With military-grade lead plates and excellent exterior quality, you will receive a product that stands both the years and the wear.
Strong & Performance-Oriented
Everyone knows that most deep cycle batteries for boats are 12v, which is the perfect charge to turn on any system without problems. So, 12v marine batteries are common.
However, when it comes to AMPs, it is normal to find almost all of them below the 70Ah level, but not with the Vmaxtanks SLR-125.
It is capable of delivering up to 125Ah in a single charge, enough for a more reliable & effective machine-starting experience.
Perfect for Entire Electronic Systems
A deep-cycle battery doesn’t just work for starting an engine but works excellently well when it comes to powering up energy-demanding electronic systems of boats and RVs.
This battery does it without problems, to even the most demanding systems that can drain other batteries out in just a few minutes – the Vmaxtanks AGM will stand up to 10 hours effortlessly.
2. 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.
3. Optima Batteries OPT8020-164 35 RedTop Starting Battery [Best Marine Cranking Battery]
Ladies and gentlemen, if you’re looking for a marine cranking amps battery that is able to issue a high burst of ignition power while retaining enough energy for your marine accessories, then search no further.
We have total faith in the Optima Batteries OPT8020-164 35 RedTop Starting Battery and are convinced that it will serve you remarkably.
And guess what? If you get up and discover that your car or truck battery is not working, this marine battery will come in handy; it’s a true multipurpose.
When it comes to resistance, nothing surpasses the Optima Batteries OPT8020-164 35 RedTop Starting Battery. At least not any battery we’ve come across and bearing in mind how many we’re talking about, this battery is really sturdy.
If you normally sail in areas with rough tides, then you will need a battery that can take the blows, and the Optima Batteries OPT8020-164 35 RedTop Starting Battery will not disappoint you.
You know how some batteries have to be kept in a certain way all the time so the acid doesn’t pill? Well, if you have had to deal with that, you can keep the battery aside and get the Optima Batteries OPT8020-164 35 RedTop Starting Battery.
This battery is spill-proof, allowing you to keep it in whatever way you like without worry, and it is also maintenance-free.
Utilizing the revolutionary spiral-cell technology, this battery offers you a ton of benefits. The spiral-winding plates are able to maintain close tolerances, making the performance and quality unmatched.
4. 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.
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.
5. Mighty Max ML35-12 Light Marine Battery Sevylor Minn Kota
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.
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.
6. Universal UB121000 Deep Cycle AGM Battery
Durable, versatile, reliable and outstandingly useful, the UB121000 deep-cycle battery from Universal will quickly help you at starting entire electronic systems, providing fast and yet stable performance.
It is almost entirely maintenance-free and will go perfectly well in any boat, RV or electronic device you need to power up.
More Reliable Charging
The deep-cycling performance of the AGM from the UB121000 battery is outstanding in its entirety – delivering top-notch consistency and brilliant charge throughout its lifespan.
It is capable of holding the charge for up to 6 months without use, so it doesn’t require maintenance or constant recharging, making it reliable and extremely convenient.
Very Strong & Steady Energy
The 100Ah reserve capacity of the Deep-Cycle AGM battery from Universal will aid in recharging any engine or electronic system you can encounter, whether it is in a relaxed or a harsh and challenging situation.
Thanks to its energy efficiency, it maintains trolling motors & solar systems steady and consistent in every condition.
Resistant & Convenient Build
AGM build the most sought-after design in the market, and there’s no doubt why: it maintains batteries with a charge for longer and demands little to no maintenance while making them spill-proof.
This battery has all that, plus one of the most resistant and vibration-free builds, which deliver excellent convenience entirely. A cheap marine battery option with good quality.
7. Optima 34M BlueTop [Best Marine Starting Battery]
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.
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.
8. VMAX857 AGM Marine Battery ideal for boats and 18-35lb 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 deep cycle 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.
9. Exide XMC-31 MEGACYCLE AGM-200 Sealed Maintenance Free (AGM) Marine Batteries Review
CCA (cold cranking amps in full) is a very important factor to take into consideration when looking for a suitable battery, as it determines whether or not your boat will start when it’s very cold.
With a CCA rating of 1110 at 32 °F and 925 at O °F, it’s very unlikely that you will have problems starting your trolling motor.
The reserve capacity is also good, at 200 minutes.
The Exide XMC-31 uses AGM technology to offer optimal recombination rate and avoid the dry-out of cells. This technology also ensures there’s optimum element compression, which in turn ensures there’s stability during high-cycling operation and when there’s lots of vibration.
Most other batteries offer you a warranty of 1 year, but the Exide XMC-31 offers you more; you get a warranty for double the duration – 24 months. If you notice an issue with the battery during this time, you’re assured of free replacement.
10. Odyssey 34M-PC1500ST TROLLING Thunder Marine Dual Purpose Battery
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.
11. VMAX MR127 12 Volt 100Ah AGM Deep Cycle Maintenance Free Battery for Boats
Vmaxtanks is one of those brands that are worthy of your trust; the quality of their batteries is unmatched, and they’re very supportive to their customers.
The last item on our list is from Vmax, and it’s got lots of advantages that we believe you will find useful. The VMAX MR127 uses an electrolyte suspension system and AGM technology to ensure the electrolyte is completely absorbed and contained.
With its sealed lead-acid system, the battery ensures there are no acid spills, and thus gives you freedom on your choice of a mounting position.
As there are no silica gels or other contaminants in the battery, you don’t have to worry about dangerous fumes being released.
If you don’t have a battery box, consider getting this battery and the MinnKota Trolling Motor Power Center, which we’ve covered above. The battery fits perfectly in there.
Like the other Vmaxtanks batteries we’ve covered in this post, the VMAX MR127 utilizes AGM technology and a unique chemical and physical structure to boost strength, reliability, and performance.
It’s the kind of battery that allows you to be out in the sea for more than five hours, trolling almost all the time.
12. Sealed Lead Acid (AGM) Deep Cycle Battery - DCM0035 replacement battery
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.
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!
13. Odyssey 31M-PC2150ST-M TROLLING Thunder Marine Battery
How would you like a battery that gives you a massive 400 cycles? Amazing isn’t it? That’s life thrice the lifespan of ordinary batteries! The Odyssey 31M-PC2150ST-M TROLLING Thunder Deep Cycle Marine Battery offers you not only that but also the ability to discharge the battery up to 80%.
This battery is a dual purpose power storage beast; you can use it for starting the motor as well as powering your onboard devices and lights. It kicks the onboard motor to life, and still remains with adequate power for your electronic accessories.
Utilizing AGM technology, the battery eliminates the need for extremely careful storage; there’s no risk of an acid spill.
If you need a durable marine battery, the Odyssey 31M-PC2150ST-M TROLLING Thunder Marine Battery won’t disappoint you. the terminals are made of brass and coated with tin to prevent corrosion.
And by the way, if you love the environment, or if you’re concerned about harmful gases being emitted, then you will love to know that the terminals are sealed carefully; the gases are trapped inside, where they’re continually recycled.
Additionally, the battery’s plates are made of pure lead, which makes recycling easy. So, when at last the battery’s life is over, you don’t have to fret about where to keep it or how to dispose of it; you can just have it taken to a recycling plant.
This battery packs about 15% more plate surface area than other batteries of its class, and you know what that means? The dead space is avoided, increasing power and reserve capacity tremendously.
14. Marine Battery Accessories: MinnKota Trolling Motor Power Center
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?
What to Look before to Buy the Best Marine Boat Batteries?
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 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 deep cycle 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, instead, 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 deep cycle 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.
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 deep cycle 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 deep cycle marine starting battery also determines the power holding reserve capacity and the output.
Different Types of Best Deep Cycle Marine Battery
There are 3 main types of deep cycle marine batteries. These are:
The three types of deep cycle marine batteries have different energy output levels, which are quantified in amperes. They also have varying prices, depending on the output and the lifespan.
When selecting the type of battery to buy, you will need to think about the size and type of your boat, as well as how you normally use your it. And certainly, your budget is another important factor to bear in mind.
Let’s examine the 3 types.
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 deep cycle batteries might be a good choice for someone on a budget, they’re not the best option if you’re looking for 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 deep cycle batteries. Another problem is with the maintenance, as the deep cycle batteries are unable to tolerate high vibrations and you need to keep the deep cycle 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 deep cycle 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.
Marine Battery Take Care and Maintenance 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 deep cycle 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 deep cycle 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 deep cycle battery system. Thus, after you charge the dual purpose 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 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 dual purpose battery charger. A wet dual purpose 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 dual purpose battery. A voltmeter facilitates taking the volt reading, and you could also use it for load testing.
- Recharge the deep cycle battery as soon as possible because if you allow it to remain in the discharged state too long, the battery’s charge reserve 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 deep cycle 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 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 amps delivered by a lead-acid dual purpose battery for 30 seconds at 32°F, so the output is or at above 7.2volts (the minimum power needed for kickstarting 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 battery that meets your boat’s CCA requirements.
Older deep cycle 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 batteries needs more maintenance. Although most type of battery requires at least some maintenance.
3. The date of manufacture
Even a new, unused dual purpose battery loses effectiveness and fails to keep the charge as times moves by. A dual purpose 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.
Best Marine Batteries on The Market : Top Brands
You may ask who makes the best marine battery. Well, here we listed some of the top deep cycle marine battery brands. Have a look below.
Vmax is one of the most trusted brands in the market, specializing in the manufacture of high-performance batteries that are suitable for heavy-duty needs with exceptional deep cycle capabilities.
The brand uses AGM technology to manufacture their batteries, designing them to meet the needs of challenging applications, say there’s a power source need for the lights, the trolling motor, the refrigerator, the water pump and more. You can count on a Vmax dual purpose battery to provide you with adequate power source for all those needs.
And, the best part is, you get high performance with a minimal need for maintenance. For instance, none of the Vmax batteries we’ve listed on our review requires you to keep adding water.
And again, their marine batteries are dual-purpose, in the sense that you can use them either on a boat or an RV. Having the best batteries for boats can make things easier.
Their customer service team is also dependable in case your dual purpose battery arrives with a problem or develops an issue or in case there’s something you need help using the battery. Their off road battery is also one of the best quality in the market.
Many battery users recognize Optima batteries as the most long-lasting marine batteries out there.
How does Optima do it? The brand uses special technology, called Spiralcell and Pureflow, to give its batteries superior resistance against shock and vibration. Safe from those two life threats, Optima batteries enjoy a long life.
Another good thing about Optima batteries is that they don’t leak acids or fumes even when tipped. That is made possible through their AGM new design, and it gives the user lots of peace of mind.
What we have noticed with the Optima batteries is that no matter how extreme conditions are, you can count on them to offer you power.
Odyssey is one of the oldest (been around for over a century) biggest deep cycle marine starting battery brands on the market, with manufacturing firms in over 10 countries and service stations across the globe.
The most amazing feature that we noted on Odyssey batteries is their recharge efficiency. For instance, the Odyssey 34M-PC1500ST can be stored for up to 2 years without needing a recharge.
Their warranty is also quite attractive; you get a 3 or 4-year full replacement warranty, just as long as you meet the terms, for instance, the damage didn’t result from negligence. Check our Odyssey marine battery reviews above for more.
4. Exide Technologies
Exide is a widely-known leader in the manufacture of lead-acid batteries, operating through various business groups around the world.
The brand’s headquarters are in Georgia, where there are big, state-of-the-art manufacturing plants. And, there are recycling factories throughout the US and other parts of the world, including Australia and Europe.
That means that when you purchase an Exide Technologies dual purpose battery, like the Exide XMC-31, you don’t have to worry about the disposal. You can just have the battery shipped to one of their recycling plants.
Like the other brands we’ve discussed, Exide provides you with high-performance dual purpose batteries that not only offer you adequate power but also make it possible for you to attend to other businesses, as they’re maintenance free. Check our Exide marine batteries reveiws above for more.
How to Use and Setup Deep Cycle 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 Installation
- 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.
- 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.
- Before reconnecting 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.
- 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.
- 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.
- 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.
Disposing of the Battery
Rather than tossing the old battery to the garbage, why not recycle it? And actually, in most cases, the battery is largely recyclable. By recycling the battery, you reduce waste and better the environment.
Caution: a battery normally has hazardous chemicals and vapors, and thus the disposal needs to be done carefully. Again, it’s always advisable not to dispose the battery with other waste. And note, it’s usually unlawful to dispose batteries in the normal trash.
Not sure where to dispose the waste? Visit the call2recycle directory; there’s a list of recycling centers over there, and they’re sorted by zip code and state.
You could also call the manufacturer or the retailer who sold you the battery to inquire more on safe disposal.
Benefits of Using Deep Cycle Marine Battery Specially
So, you’re at an auto shop and you need a battery for your boat. You tell the guy behind the counter that you need a battery for your boat, but that any battery will do, even if it’s a car battery; the only thing that matters to you is the size and the price perhaps.
Okay, before you pay for any battery, there’s something you need to know – if you’re looking for a good experience, you’ll not get any battery available; you will get a deep cycle marine battery specifically.
Why is it so? Here’s why:
In summary, a deep 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 deliver lots of energy to the car as the engine starts, and after that, the battery just sits in there doing pretty much nothing, apart from receiving power from the electrical system.
That is why you hear of car batteries being referred to as 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.
Now, before we look at how to get the best from your marine battery, let’s bust a popular myth: You might have heard a few people say that if you place a battery on the floor, it will discharge.
Well, that’s not true. But, placing batteries on a piece of wood is a good way of insulating the bottom form the low temperatures.
Tips to Get the Best Performance from Your Deep Cycle Marine Battery
Aside from the motors and the electronics, your deep cycle marine battery is probably the most expensive accessory on the boat. Getting the battery costed lots o money, and as such, it’s only fair that you get great service from the battery for a long time.
Realize that marine batteries fail early from a number of causes, but most of the time, these causes are preventable. In this part, will tell you about these causes and give you tips on boosting the performance of your deep cycle marine battery.
Reasons why marine batteries fail
To understand how to tune your battery for the best performance, you got first to understand the common causes of failure:
i. Extreme temperatures
Though boat batteries are pretty sturdy, they’re still vulnerable to damage from temperatures that are either too high or too low. When the temperatures are extremely high, the battery will expand and push out the power faster than normal.
So, temperatures that are too hot lead to increased discharge and electrolyte loss.
When it’s too chilly, the battery discharges at a rate that is much lower than normal, as the battery is forced to work harder than usual.
In both cases, there’s too much strain on the battery, and that reduces its lifespan.
Tips: During those harsh temperature days in winter and summer, try keeping your boat battery in a temperature regulated environment.
ii. Incorrect charging
Every deep cycle marine battery comes with its recharging specifications, and if you’re to use the battery for a long time, you got to adhere to these specifications. Again, some people want to charge their batteries super quick with high voltage, but that could end the battery’s life prematurely.
There are a few issues with high-voltage fast charging including the fact that there can be sulfation – this is the displacement of the internal elements that give the battery unique power. Corrosion and discharge rates also increase with high-voltage fast charging.
Tips: Try following the manufacturer’s guidelines on recharging. Stick to the specified charging voltage and don’t overcharge the battery. Apart from that, install a high-quality charger on the boat that will enable the battery to live the full length of its life.
iii. Cell sulfation
A flooded battery falters early when underused. If a lead-acid battery discharges less than 30% of its reserve capacity, acid accumulates on the lead plates as sulfate crystals, and when that happens, the battery’s performance gets significantly inhibited. The result is an untimely need for replacement.
Tips: Use a battery charger with an equalization option for ramping up the voltage once in a while. That way, the buildup can get dispersed, and the negative effects can be reversed, so the battery lasts longer.
iv. Improper storage
The way you store your battery contributes a lot to its health status. If you store the battery without cleaning it, the battery can suffer corrosion, and become obsolete prematurely. Again, if you store the battery without charging it fully, recharging it later can be a bit difficult.
And, as we mentioned earlier, the temperature level affects the life of the battery. Thus, if you live in a place where the temperature is either too high or too low, look for some kind of insulation.
Tips: Before storing a battery, ensure it is full charged and clean. Store the battery in a dry place where the temperatures are moderate.
v. Misusing the Battery
Even though many batteries look almost the same, they’re normally not interchangeable. As we discussed in a previous section, marine batteries are designed for a range of purposes, and using a car battery in its place is likely to give you a bad experience.
Also, using the deep cycle marine battery to crank your car engine might reduce its lifespan. Only stick to the applications indicated by the manufacturer.
Tips: use only a battery labeled marine. When selecting a battery, go for one that’s able to handle all your power needs, and, don’t mix different battery types, like flooded and AGM in the same configuration.
vi. Incorrect installation
When the battery is installed poorly, there’s bound to be accidental fires, acid leaks, and possibly battery explosions. Loose cables and posts that are maintained poorly could also lessen the battery’s lifespan.
Tips: install the battery in a battery box of appropriate size. Straps can help secure the battery and prevent sliding and shaking when the boat moves. Also, secure the cables to the terminals with cable boots and screws.
Now that you know why marine batteries fail, and how to stop them from failing, why don’t we examine a few more ways in which you can tune best rated marine batteries for the best performance?
Though these are no-brainer tactics that take just a few minutes to exercise, they might give your boat battery years of sound performance.
- Use the proper charger – the manufacturer has specified a particular model, and by using it, you avert the risk of damage that unapproved chargers impose on your battery.
- Recharge the battery promptly after use.
- Remove any corrosion from the terminals – a baking soda-water solution will be very helpful.
- If you’re using a flooded battery, maintain its water level – don’t forget to use distilled water.
- Keep the battery fully charged during winter and maintain the recommended water level for storage.
What Is the Life Expectancy of a Marine Batteries?
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.
Frequently Asked Questions (FAQs)
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. How much does a battery discharge per month?
Ordinary batteries discharge between 2% up to 20% of their energy a month. But this depends on temperature, the age of the battery, and type.
An AGM battery with six months of use will surely discharge less than a cell battery with two years of use.
5. Is discharging or overcharging bad for the battery?
Both are bad for your battery. Overcharging may cause internal composition changes which could eventually stop working, especially in cell batteries.
Discharging while it doesn’t necessarily make a battery stop working, it reduces the lifetime, or may even produce the battery never to catch a charge again.
6. 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.
7. 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.
8. What’s the link between cycles and lifetime of a battery?
A cycle is each time your battery has been discharged and recharged, and with each cycle, the lifetime of it shortens. The more cycles the battery has, the less life it will offer.
However, you can cycle a battery with different energy percentage, like 50% or 10%. The less charge the battery has when recharged (a cycle), the more lifespan it loses.
9. Do I need to refill the battery often?
You will only need to refill cell batteries, and yes, it is indispensable. Typically, it is recommended to refill them once a month. They are not zero maintenance batteries.
10. What are some of the most important battery rating?
The amp-hour rating, which indicates the battery reserve capacity, is the most common battery rating. The unit is basically a multiplication of the time of discharge (in hours) by the current flow (in amps). For instance, a starting and deep cycle marine battery that gives you 10 amps for 25 hours is rated as 100 AH (standing for amp-hours).
Although the amp-hour rating is important, it should not mislead you into thinking that the battery is excellent and will work for you. The quality of the internal parts as well as the battery’s general design matter tremendously.
For example, you might find a battery with an amp-hour rating of 150 but called upon to provide power over a few hours; the battery doesn’t hold up very well; it hardly goes overnight without needing a recharge.
Trying to push the battery renders it obsolete within a couple of months. Another battery might have a rating of 130 but it’s able to support an electrical load for days without requiring a recharge, and it’s able to serve you for a few years.
Therefore, apart from the amp-hour rating, be sure to consider also the cold cranking amps and reserve capacity ratings.
11. How does the CCA rating help in battery selection?
CCA stands for cold cranking amps and refers to the power that you can get from a battery, continuously, for 30 seconds and at 0 °F.
The number indicated by the rating refers to the number of amperes delivered; for instance, a rating of 300 CCA means that the battery can provide 300 amps for 30 seconds when the temperatures are at 0 °F.
The higher the CCA rating, the better, as that shows you the battery can be able to crank the engine when the conditions are not very favorable.
12. How does the reserve capacity affect the quality of a battery?
The reserve capacity refers to the duration in which a battery (fully charged) maintains a helpful power discharge (above 10.5 volts) at 25 amperes before the discharge grows unhelpful (below 10.5 volts).
This rating is normally expressed in minutes, and the more the minutes, the better the battery in terms of the ability to run the electronic devices on your boat including the lights and the pumps.
Actually, if you’re very concerned about the battery’s ability to offer you good deep cycle service, consider the reserve capacity before other ratings. A battery could have the highest CCA or amp-hour rating, but if its reserve capacity is inadequate, then battery won’t be of much use. Sadly, the market is flooded with such batteries.
What makes high reserve capacity so hard to come by is that it’s not very easy to engineer into a battery; it’s expensive and needs high-quality materials.
Other ratings that are very important include the cycle life and the service life.
13. What does cycle life refer to?
A battery cycle refers to the change in charge state from fully charged to fully discharged and back into fully charged. Now, cycle life denotes the overall number of cycles that a battery can have before it fails.
Obviously, you should go for the highest number of cycles, but the problem is that many manufacturers either do not indicate the life cycle (many don’t even test their batteries for that).
Therefore, to increase your chances of getting a battery with a long cycle, go for a deep cycle AGM battery. Deep cycle AGM batteries are better than cranking batteries, which are not designed for a long life cycle.
14. How do deep cycle batteries differ from cranking batteries?
Many sellers out there are misusing the term “deep cycle”, using it to refer to a heavy-duty battery, and this confuses the buyers very much.
So, as a consumer, you need to understand that a true deep cycle battery is one that can withstand numerous charge-discharge cycles without losing its capability to hold power.
Realize that many batteries out there being advertised as “deep cycle” have slender plates and low-quality porous separators which cause them to sulfate and fail after a few cycles.
Cranking batteries are batteries that can provide a high amount of power, enough for starting an engine but they aren’t normally able to provide power for long and their life cycle as well as service life, is short.
One major difference between the two kinds of batteries is that deep cycle batteries can function well as cranking batteries, but a cranking battery doesn’t normally function well as a deep cycle 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.
Last Updated on August 6th, 2020