Since I can remember, I’ve had a passion for the wilderness and adventure. I’ve learned my trade everywhere, from the rock faces of the Himalaya to the wilds of South America and Europe. My vision is simple, to connect more people to the awesome power of the great outdoors.
John is an avid traveler, hiker, and RVer. Moreover, it seems like he knows everything when it comes to fishing and hunting: his father started sharing all the tips and tricks he knew when John was a kid. No wonder we trust his opinion every time a new article is being created.
Last updated: December 24, 2021
Outdoorsly is reader-supported. We may earn a commission through products purchased using links on this page. Learn more about our process here
You should already know how necessary a car battery is in starting up the contraption. On the marine front, batteries are also as important in the running of a boat and even more so than they are needed in cars. In addition to starting up a boat engine, they as well power all-electric appliances on the vessel.
The Odyssey 31M-PC2150ST-M features as our editor’s choice where the best marine batteries are concerned. This is because the battery is impressive in many features, including a high recharge efficiency, dual-purpose use functionality, and excellent warranty terms, to name a few. You will also note that the nine other products mentioned have characteristics that allow them to be featured on our list. We initially started with more than 20 products, and hence, those that were not as impressive did not get on the list.
Our team has spent a record number of hours researching each battery. As such, similar criteria were used to help rank each option with our first checkpoint being the purpose of the battery. In the case of marine batteries, there are those than only start up the engine; then, there are those that power the engine and electrical appliances continuously. The capacity of the devices also has to feature as we determined how much power the battery can hold. Other crucial checkboxes included the CCA, type of battery, dimensions, and other factors, as well. What culminates from the exercise above is a comparison table listing the best marine batteries in descending order. In-detail reviews of the products then follow that. The last section is a buying guide, and that should shed some light on how you should create your own list.
Other features: 3-10 years of service life, limited three and 4-year full replacement warranty, 70 percentage longer cycle life, highest recharge efficiency, 100 percentage recharge in 4-6 hours, vibration resistance-design, low temperature operation
One impressive aspect of this device is the dual-purpose functionality. As such, it can be used to both start the boat engine and to continuously power a motor. This is an absorbent glass mat battery, hence the AGM initials depicted in the features listed. As such, you will enjoy maintenance-free use with this device.
Also, you will note that the design of the battery is spill-proof; thus, you are allowed to position the invention any which way you want, and it will still function. On top of the battery case, there are two different types of terminals, and that will make the device a more versatile purchase.
As compared to other deep cycle batteries, this device will feature a 70% longer life cycle. Recharge efficiency is also something to write home about on the device. You can go from practically empty to full charge in a matter of 4-6 hours. Also, due to the motion on your boat, you are going to appreciate the vibration-resistant nature of the battery. Another impressive offering is the battery’s capability to work in a wide range of temperatures. They can vary from -40 degrees Celsius to 80 degrees Celsius.
What makes it stand out?
Versatile positioning due to spill-proof design
Doesn’t take long to recharge
Up to four years warranty
Works well in low and high temperatures
Which disadvantages must you keep in mind?
This device seems to be the most expensive offering on the list
With a reserve capacity of 260 minutes, this device performs well above some of the counterparts on this list, including those by the same manufacturer. However, you do see some features unique to this brand of devices that you are going to love.
The first is the inclusion of military-grade plates to improve performance and bring about the long life of the battery. You will also see a handle that makes carrying this invention a breeze. It might seem like a thing that every manufacturer would include in their batteries, but a lot of them seem to overlook handles. Life span is also expected to be from eight to ten years.
Why is it special?
Easy to carry
No toxic emissions or spills
High-quality component pieces
What are the flaws?
The handle might break after some time due to the device’s heavy nature
The invention also features a high price point as compared to others on the list
In comparison with the Optima 8016-103 D34M below, the cranking capacity is a little less. However, you can also see an increase in reserve capacity by about 20 minutes. The design and spiral cells incorporated in both gadgets seem to be something to write home about. If you plug it into a power source, you are bound to be amazed at how fast the device can recharge.
You will also note that since this is an AGM type battery, it is less likely to spill or leak materials from the encasement. As such, there is no need to stress about where to install the device on the boat as it will perform as expected in any position.
What are its best features?
Solid build leading to shock resistance
Doesn’t require any maintenance
What could be improved?
While the device does come with a warranty claiming if anything happens can be a rather lengthy process
If nothing else, the Optima 8016-103 D34M is unique in its exterior design, taking a form that not many other AGM marine batteries will feature. However, this is not a bad thing as due to its unique design; it can boast of features like the high resistant to vibrations. Consequently, this is one of the more physically durable marine accessories you can own.
Once you get it inside your boat, you can mount it in any position, whether sideways or upright.
What do we love it for?
Easy to mount
Dual-purpose for both producing Continuous energy in small bits and large amounts of energy to start engines
What were we disappointed with?
Some users have noted that the shipping package needs improving
The VMAX MR127 sits between the VMAX MR96-60 and the VMAX SLR-125
In terms of reserve capacity. You will also see a variation in group size where all three options are concerned. As is typical with the manufacturer, you get carrying handles as well with the purchase. Once this device is purchased, it requires little to no maintenance, with the only requirements being that you position it correctly. There is also the bonus of heavy-duty grids to boost battery life.
What stands out?
Carrying handles are incorporated
What cons did we manage to find?
The warranty only lasts one year, so if anything happens after that you may have to purchase a new battery at a similarly high cost
If the goal is to find a deep cycle battery that you can easily handle and transport the VMAX MR96-60, maybe it. As such, it comes with built-in handles that you can use to lift and move the device from place to place. Also, this battery is similar to the Odyssey 31M-PC2150ST-M in that the primary component material is absorbent glass mat. This allows the device to be maintenance-free. There is no provision for you to open, check, or add anything to the battery. Even then, it still manages to give eight to ten years of service.
As a bonus feature of the construction, the battery innards are both non-spillable and non-toxic, making it a safe bet to have around your kids. Also, noteworthy are the military-grade plates that are incorporated into the design. They are as well one of the reasons for the battery’s performance.
What are our favorite features?
Comes with built-in handles for a more comfortable carry
Fast recharge rate
What could be better?
Only provides continuous energy in small amounts
Previous users as well don’t seem to have many complains about the device
Other features: high discharge rate, wide operating temperatures, long service life and deep discharge recover, rechargeable, can be mounted in any position, resists major shocks and vibration, long-lasting performance in high and low temperatures, a 30-day refund policy, full 1-year warranty
The Mighty Max ML55-12 also makes a rather compelling case for why it should feature on our list. You, of course, have first to establish that this is a deep cycle battery meant to release small amounts of energy over some time. On the inside of the casing, the device is filled with absorbent glass mat, which is then firmly enclosed. This supports the fact that you can mount the battery on your boat in whichever position you desire.
A key selling point for this device is the long service life you can expect if you make the purchase. If you are in rough waters, the device will be able to take the vibrations that come by as a result and still maintain its integrity. Also, this is one battery that you can use both in the winter and the summer. The high performance both in high temperatures as well as in low temperatures may come in handy, especially in areas where climate fluctuates a lot.
You as well have an option to return the device to the manufacturer if you are unhappy with it after thirty days. The rest of the warranty works for up to a year after purchase.
While gel-type marine batteries are not a common occurrence on our list, the Renogy 12V 100Ah stands out in this regard. From the image provided above, the outward design is rather simple. Nevertheless, this does not stop this device from performing on par with other top quality gadgets. The manufacturer, while designing this battery, was looking to pair it up with solar power applications. As such, if you have a solar panel installed on your boat, this may be your best bet.
As is expected of a deep cycle battery, there is low self-discharge associated with plugging this device onto your boat. Another thing to note is the triplex sealed construction. You can, therefore, expect there to be no spills or leaks whatsoever.
What are its best features?
Spill-proof and leak-proof
Ideal for solar applications
What could be improved?
Only for deep cycle use
No handles to carry the device
One user noted that the battery is susceptible to high temperatures
The Universal UB121000 is a battery offering of the deep cycle variation. As such, it is not ideal for cranking up your boat, but it will provide some much-needed power in small doses. As to the type of battery you get with this purchase, it is more or less like a two-in-one as it mixes AGM and VRLA. Nevertheless, the innards of the device are enclosed in a non-spill container. This ensures the positioning of the invention is versatile; hence, you get a more extensive array of mounting options.
As a boat user, you should know that sometimes the ride can get rough. Consequently, the battery needs to be able to withstand a bump here and there; otherwise, it won’t last very long. Also, the reserve capacity stands at about 170 minutes of continuous discharge.
Where the warranty is concerned, you can only bank on the backing of the company for one year after purchase.
Why is it special?
Incorporates both absorbent glass mat and lead-acid in its design
In terms of performance, the Banshee Group 31 marine battery for trolling motor can handle up to 400 discharge cycles. This is even where you reach 80% depth of the discharge. You should note that the device uses enhanced flooded battery technology in its construction. As such, you are advised against installing this piece of equipment upside down or on the side. Other than that, the device is practically maintenance-free.
What do we love it for?
No maintenance required
Comes with a flip-up handle
A hydrometer as well is incorporated to indicate battery life
What were we disappointed with?
Not many people have used the device; hence, complains are minimal at this point. This may change over time, and if it does, we will update you.
Things to Consider
As a buyer knowing what you are looking for is the key to making a purchase you will be proud of. As such, the buying guide below should be of immense help in that regard.
Features to consider when choosing a battery for marine use
Features, of course, bring out the best qualities of a marine battery. If you are aware of what it means for a marine cranking battery to have a particular feature, you can make smart choices with regards to your purchase. Most importantly, you can tell which features are a must-have for you and which ones aren’t.
Each of the devices mentioned above is indicated to be either a cranking battery, a deep cycle battery, or dual purpose. Each of these will have a specific use in mind during their construction. The cranking/starting marine battery, for instance, outputs short bursts of high current energy to ensure they start up the engine. Deep cycle counterparts, on the other hand, can discharge continuously. The third option, however, is a hybrid of the two. Odyssey 31M-PC2150ST-M is the perfect example of such a kind of battery.
As to the kind of battery you end up buying, there are different options to choose from. The AGM or absorbent glass mat type is the most prevalent on our list. It seems to hold a few advantages such as spill resistance, faster charge capacity, better life cycle than with flooded batteries, and more. In addition to flooded and AGM cells, there are gel options, as well.
Flooded batteries require a lot of maintenance and can only be installed upright as they may leak toxic materials. On the other hand, they are cheaper than most other counterparts. If you buy a gel battery, you are guaranteed a more extended life since they handle more charging cycles than other counterparts. They are also safer than the flooded ones.
The CCA is also something you need to look out for in a battery. CCA stands for cold cranking amps. As the name suggests, the CCA implies the amps that the device will deliver while still at 0°F. The output is not meant to last very long, and often, gets to about 30 seconds. As such, it is more commonly used to start engines. Reserve capacity, on the other hand, refers to how long the battery can continuously emit a charge of 25 amps. An RC of 140 minutes, as depicted by the Optima 8037-127 D27F, means the device can consistently produce such a charge for slightly over two hours.
20-Hour capacity (rating)
The 20-hour capacity rating will sometimes be depicted on the packaging of the battery you buy. It indicates how many amps it will discharge over that period. The VMAX MR127, for example, is rated at 100 Ah with regards to the 20-hour capacity. As such, it will discharge 4 Ah for every hour until the 20th.
Battery group size is unique to each vehicle as they are all made by different manufacturers. You will often see a direct correlation between the group size and the dimensions that make up the battery. Also, the terminal locations may be unique to each group size. If you are using a particular group size, you should stick with it as changing it up may bring up some problems. However, if the group size you are on isn’t ideal, feel free to change it up until you find the right size. Nevertheless, there is an easier way to go about this where you can ask your boat manufacturer which marine battery group size is best. Some standard sizes are depicted as 24, 27, 31, 6D, 8D, and more.
Durability and design
The design of each marine battery also has an impact on how you can use it. If, for instance, it has AGM as the main component, you are free to install it upside down as it can function that way as well. Also, check on the durability of the casing where terms like shock resistance come into play. You can as well note the cycles that the device is capable of.
Some devices will have extra features. Those made by the VMAX company, for example, come with handles which some of the other manufacturers have left out in their designs. This will, of course, give this battery an edge over counterparts if there is nothing else separating the two.
A couple of different factors affect the lifespan of a cranking or deep cycle marine battery. As such, you cannot place a timeframe on how long a device of this caliber should last. Nevertheless, lead-acid batteries are usually dependable up to the two-year mark if treated well. In rare cases, they may even get to three years.
It is sometimes possible for you to use the deep cycle battery to start your vehicle engine. However, this is dependent on whether the device is capable of the amperage needed. If you nevertheless make it a habit to do this, you may be dramatically reducing the lifespan of your investment.
A marine battery has several indications that you may need to replace it with a new one. Among them are losing the ability to hold a charge, discharging power faster than it used to when it was still fresh, trouble starting your engine, and more. When you see these signs, they are an indication that your battery is getting old.
By going through the features listed, you will realize that the Odyssey 31M-PC2150ST-M deserves the title of editor’s choice and would thus be an ideal investment. Among the quality features is the fact that it can both be used as a cranking battery and as a dual cycle battery. It also promises long service life as compared to most other options. There are as well a few characteristics that give it priority over others when it comes to making a purchase.
The VMAX SLR-125 presents itself as one of the best deep cycle marine batteries available. It incorporates military-grade plates, and this is one of the factors that allows the device to have a long lifespan. While the initial investment is significant, it makes up for that in that you don’t have to buy another battery for a long time.
You may also want an easily mountable option that is an all-round quality battery as well, and this is the Optima 8037-127 D27F. Faster charging and no maintenance are just but two reasons for you to buy this tool. There are other reasons as well, such as being dual purpose. Even as you consider other options these three have already established themselves as forerunners. Nevertheless, the whole list makes for ideal purchases to the right user.