If you’re on a boat then there’s a good chance that you need a battery, either to start your motor or run the electrical equipment you have on board. Choosing the right battery is vital to you getting consistent performance and not having to worry about power.

There are two main battery options of starting and deep cycle batteries depending on your needs. There are some great marine battery reviews out there and we have looked at them all to bring you the best marine battery on the market.

Choosing the best boat battery though isn’t easy due to their technical specifications and different uses. Here we have created a great buying guide to guide you through the process so that you can make an informed decision. So read on so you can find the top rated boat battery which is going to be perfect for your needs.

How To Choose The Best Marine Battery – Buying Guide



In terms of power output for deep cycle marine batteries the measurement that you most want to look out for is the ampere hours (Ah) which is a measurement that should be on every deep cycle battery. This is a figure of how many amps a unit can deliver in an hour. If the figure is 20Ah then this means it could provide 20 amps for one hour.

This figure is divisible though which gives batteries their long life so you could switch this and say that a battery with a rating of 20Ah will be able to give you 1Ah an hour for 20 hours. In simple terms though, the higher the Ah figure the more power would be able to be placed into your devices you the larger the figure the better.

It’s important to work out how much power you’ll be using as the Ah figure can depend on various factors such as the size of the battery so if you want a smaller battery then you might have to sacrifice form Ah in order to do that.

Strength And Durability

It’s important for a battery to be well-made for a number of reasons and mainly due to their acidic contents inside. If that battery is on a boat though it’s even more important for it to be strong due to the extra stresses and vibrations that it’s likely to go though.

The plastic container that the battery comes in has to be made to a high degree of strength and it needs to be resilient to the contents inside. This is where you want to look for non-spill batteries and ones that are sealed as they will give you the most protection against something going wrong. Most of the top models are made out of ABS plastic which will be able to withstand a lot of punishment. You also want your battery to be able to withstand the natural vibration that can be found on a boat.

Deep Cycle And Starting

When it comes to marine batteries there are two main types that you will see and it’s vitally important to choose the correct one before you take it onto your boat otherwise you could find that you have a battery that is not fit for use. The two different battery options have two very different roles when it comes to operating your boat.

Deep cycle batteries are ones that can keep a low and consistent level of power which will be able to run all the electronic devices on your boat. It’ll run off a 12 volt supply and from this you’ll be able to link up any device that you want while you’re out there on the water. In terms of the power figure you’re looking for here you’re looking for a battery with the highest ampere hour (Ah) possible as this will give you consistent power for the longest time.

The other form of battery which is unsuitable for running your devices is called a starting battery. As the name suggests, this battery is used for starting your motor. This a completely different operation to running your electronics and the power output figure that is most important in this scenario is your cold cranking amperage as this dictates how effective your battery will be from a cold start.

There are though batteries that offer the best of both worlds and can deliver both the ampere hours needed to run your devices and the cold cranking amperage needed to start your motor. If you’re looking for an all-in-one solution then this would be ideal but is generally more expensive. It’s vital to make the right choice though as a starting battery isn’t suitable to run normal electronics from and a deep cycle batter won’t be able to start your boat.


Reliability is important for any electrical product but with a marine battery this is even more so due to the consequences of anything going wrong. If you’re out there on the sea and your deep cycle battery fails then you could be left without any power for your devices, or if your starting battery fails then you could be left without being able to actually start up your boat.

The top brand listed here are all highly rated for their quality ensuring that you have a very reliable battery that won’t let you down at the crucial moments. Key features to look out for are if the battery is sealed, the resistance that is has to such things as vibration and heat as well as how well made the product is. Thankfully the products we have looked at here can all give you a high degree of reliability and it’s important to not buy cheap batteries which might not have the same level of reliability.

Cold Cranking Amperage

If you want to start a motor then you will want a battery that has enough power to get it going. In terms of batteries with is its Cold Cranking Amperage (CCA) which is a measure a batteries starting power. As a standard measure, this is how many amps a battery can deliver in 30 seconds a 0 degrees Fahrenheit, the higher the CCA rating the bigger the motor that can be started with it.

If you have concerns over how much power you need to start your motor then these details should be easily found on your motor of with a quick internet search. This will then give you an idea of exactly what you need. Anything with a rating of over 700 though should easily be able to start a motor that can be found on mid-sized boats.

Reserve Capacity

In regards to reserve capacity this is the time that it would take for a marine battery to fall below a voltage of 10.5 while maintaining a power output of 25 amps. This figure is measured at a temperature of 80 degrees Fahrenheit in order to get a consistent and universal measurement.

The higher this figure is, the better it will be for you as it means it will be able to perform for a longer period of time. The importance of the reserve capacity depends on the amount of power that you need as if you’re only running a few small devices then it’s not too important but if you re consuming a large amount of power then you want this figure to be as high as possible.

Maintenance And Size

Having to maintain a battery isn’t a pleasant experience and it can be frustrating when you have to do it. As battery technology has moved on less and less maintenance is required in order to keep your batteries going, but that doesn’t mean that they don’t need to be looked after.

Thankfully many of the modern day batteries used for marine purposes are Absorbent Glass Mat (AGM) batteries which don’t require any maintenance at all. This makes them a much easier and safer battery to own. These batteries are also a lot stronger and more durable to prevent any leakage and can often be mounted anywhere.

In terms of size you simply have to take into account where the battery is going to go and the dimensions of it. Whether you’re taking an old battery out or replacing an existing one you need to get one that fits the space. Generally though the larger the battery the greater the performance so if you’re wanting an upgrade then you just need to make sure that you’ve got the space for it.

In order to keep your battery working for longer, there are a few tips that will help to avoid any problems from occurring and also stop any damage happening to the battery. Although batteries such as AGM don’t need to be maintained by filling them up with water, it’s still a good idea to service them every now and again to keep them in top working order.

Cleaning the battery is the first step to good maintenance especially a battery that has been at sea and is exposed to salty sea air. Removing first and rust from the terminals is vital and this can be done easily with a wire brush. It’s important to check this often as the longer you leave it, the harder it will be the clean and the bigger problem it will be, also oil lubricant can be used in the terminal to prevent corrosion.

It’s also important to charge the battery in accordance with the information provided by the manufacturer. This will give you details on the charging length as well as when and when not to charge your battery. It’s also important to check your battery for any cracks or signs of damage. This damage would be from the devices that it is charging and if you suspect this then you need to verify the voltage of the charging system.

There are also other considerations too such as storage. A marine battery shouldn’t be left on its own for long periods and if you’re only using it seasonally then it would be the best idea to get a charging device that would be able to give the battery a trickle charge to keep it maintained. It is an obvious point as well, but if you have a flooded battery then it’s vital to make sure that the water levels don’t go too low.


In terms of marine batteries there are three main types to consider and they are flooded batteries, absorbed glass mats and gel batteries. All three have their distinctive features which we shall go through here. They have various advantages and disadvantage of power, lifespan and price as well.

Flooded batteries – These also go by an alternate name of wet marine batteries and these have been the most common battery partly down to the fact that they are also the cheapest. The way they work is by the sulfuric acid inside reacting to make hydrogen and oxygen which then gets discharged via the internal vents of the battery. The only real advantage to this battery though it the price, as they need to be maintained and topped up with distilled water, they have a high discharge rate and the battery is unable to withstand a large amount of vibration. If you have the budget, then it’s probably best to look at other types of battery.

Gel batteries – These batteries also use sulfuric acid but in conjunction with silica, water and phosphoric acid as well. This blend creates a gel which is good for you as it means that the liquid inside the battery is a lot thicker which prevents any leakage, This means that the battery doesn’t have to be kept upright to keep working. The maintenance is a lot lower as well as there is no need to add any additional water to the battery. These batteries are a great mix of quality and price as they will be a lot easier than flooded batteries and are cheaper than the next option on the list.

Absorbed Glass Mat (AGM) – This is the most expensive option out there and the reason for that is that they are quite simply the best batteries on the market and the one you’ll want if you are looking for the highest levels of quality. The batteries work by using glass mat separators which sit in an electrolyte-acid solution. That means that you’ll never have to worry about filling them up with water. These batteries work very well and importantly are highly resistant to any shock or vibration making them an ideal option if you’re sailing over rough waters. The Three options generally come down to how much you are looking to spend but if you’re looking for quality, then you need to get an AGM battery.



Q: What is the standard lifespan of a marine battery?


There is no standard answer on this as it is determined by a number of different factors such as how the battery is treated over the course of its life and which type of battery that you use. With regular use a lead-acid battery will probably last for around 2-3 years with good care.

It’s important though to make sure that you read the manufacturer’s instructions so that you are caring for your battery in the right way. If your battery is nearing the end of its life then it’s important to change it promptly as you wouldn’t want to be in a situation with a battery that fails without any back-up.

After great feature of AGM batteries is their lifespan and you also have to consider how much punishment the battery will be subjected to in terms of vibration and shock. If you’re used to sailing through rough seas then a flooded battery might not last long at all. Using an AGM battery would give you greater assurances about its lifespan knowing you won’t have to change it very often.

Q: Can you use a deep-cycle battery for starting?


The answer to this question isn’t really a yes or a no, instead it’s more of a potentially. Your motor will require a certain amount of amperage in order to get started and this isn’t generally what deep cycle batteries are made for. If it has a good enough amperage then it will be able to substitute for a starting battery but it’s probably for the best that this isn’t done on a long-term basis.

Having a specified starting battery will give you assurances that you have the right amperage but also a failsafe knowing that you have two batteries that are working. Using it as a starting battery will also increase its level of use meaning that it is more likely to require maintenance and replacement more quickly.

There is always the in-between solution though if you’re only looking to have one battery and that is to have a battery that is specifically made to do both. This will be able to start your motor and run your devices with ease and the dual nature of these batteries can be great for those either looking to cut costs or those for whom space is at a premium and can’t install two separate batteries.

Q: When do I need to change my battery?


There will be a time when the battery starts coming to the end of its life and it needs to be changed. There are some keys signs that you need to know so it’s not too late and you’re not left out on the water with a battery that has failed. One of the biggest signs is if you’ve had to jump start your battery. This means that the battery is dead so you need to identify why. I could just be a loose connection but it could also mean that your battery has failed.

Another sign is if your motor struggles to start and this could be a problem with the battery. This could be something such as cold weather but it can often be a sign that your battery is weak and probably needs to be replaced. Another sign is electronics dimming or cutting out when the battery gets going, this is due to the battery stuttering to get a charge.

There are other key signs too such as the battery not holding a charge and discharging its power far too quickly. These are all key signs and if you are getting any of these then it is a huge warning sign. You don’t want to leave your battery for too long as you don’t want to be stranded out at sea. In order to prolong the life of your battery you need to maintain it on a regular basis but all batteries die over time, so if your battery is becoming too weak then it’s important to get rid of it as sooner or later.

Q: What is the average temperature to work with a marine battery?


There are no precise facts on what temperature will work best for a marine battery except for the general rule that batteries work better in the warm than they work in the cold. You might have had it in a car on a cold winter morning when it takes longer to start up than it would do on a warm summer day. That is due to the fact that the battery is not able to provide as much power as it usually can but it’s hard to determine an optimal temperature that a battery will work at.

If your battery is struggling in the code then it could be a sign that it can’t quite give you the same amount of power that it once did. This can be an early sign that the lifespan of the battery is nearly up and it’s time to get a replacement.

Q: How much does a battery discharge per month?


Batteries will gradually discharge over time which is their natural way until they reach a point where they can no longer give you the level of power that you’re looking for. This discharge rate can vary on a number of different factors but can be anywhere from 2-20% on a monthly basis.

The factors that can determine this are the age of the battery, the temperature they are working in and perhaps most importantly the type of battery that it is. As mentioned before, AGM batteries are the most expensive because they are the best and they will discharge a lot more slowly than the other two options.

It’s facts like this which should make it a lot more attractive to buy an AGM battery. It can be seen very much in the same way as LED lights are in your home. There is a most expensive outlay but that investment over time can be paid back as they don’t need to be replaced as often. If an AGM is 50% more expensive than another type of battery but lasts for twice as long, then in the long-term you will be saving money.

Q: Is discharging or overcharging bad for the battery?


Yes and yes. Both of these things can be bad for your battery but sometimes it can be impossible to avoid them unless you are constantly checking on the state of your battery which wouldn’t make for the most enjoyable trip out on the boat. Overcharging of the batter will cause changes in its internal composition which over time will gradually eat away at the batteries capabilities.

Discharging a battery as well will reduce its lifespan and can cause it to stop working altogether. While it can be a difficult ask to constantly monitor whether a batter is overcharging or discharging, it’s important to keep an eye on it to make sure that this is kept to a minimum and the battery is cared for in the best possible way.

Q: Do I need to refill the battery often?


This depends on the type of battery that you have as a lot of modern batteries such as the AGM won’t need refilling which can take away a lot of the burden of maintenance. Cell batteries though will need refilling as often as they need to be, but this in general will be about once a month.

In order to prevent yourself from having to so this it might be for the best to upgrade to an AGM battery as mentioned but also gel batteries don’t need to be refilled either. These two batteries don’t require maintenance so if you’re looking for a battery with the easiest care possible then it’s worth investing in one of these two options.

Q: How does the reserve capacity affect the quality of a battery?


As previously detailed the reserve capacity of a battery refers to a fully charged batteries ability to have a power output of at least 10.5 volts at 25 amperes of above and the about of time it can sustain this for is its reserve capacity.

The more minutes that it shoes, the better the battery is at providing power for long periods. This shouldn’t be confused though with its actually charging time as it’s more than likely the devices that you’re running off the battery will require a lot less than 10.5 volts and/or 25 amperes so this figure is simply just a useful measure to compare batteries.

When looking at this figure though it’s also important to look at it in the context of the other features as well, a battery with a great reserve capacity might have a terrible CCA or an appalling Ah rating. These figures need to be looked at together in order to get a true picture of exactly how good or bad a battery is.

Reserve capacity though is important and if it has a high figure then it’s likely that the other markers of quality will be high too, but it would be wrong to presume this. Batteries aren’t just about numbers even though they are important. A reserve capacity is often an indicator of the quality of a battery and its ability to deliver power but there are also many other measures of a batteries quality as well

Q: What does cycle life refer to?


A batteries life cycle is essentially its heartbeat, it refers to how many times the battery can go from fully charged to fully discharged before it shuts down. Its life cycle is a measure of how many times it can be fully used and this can depend on a number of different aspects.

Obviously the higher the figure in terms of its life cycle, the better but not many manufacturers will display this information or have it available.  Part of the reason for that is the number of factors that are involved in that and also the difficulty that a company would have in testing it.

Quite often this remains a hidden figure that people would have to assume based on other factors. The only real way of ensuring a high life cycle would be to opt for the best quality battery and that would be an AGM. This will last longer than any other types and there are plenty of options on the market for this type of battery.

Globo Surf Overview

If you have an electric motor or any electronics that you want to use then you will need to have a battery for your boat. There are plenty of great electronic devices that can help you while you’re on the boat but they will all be useless if you can’t get power too them. Getting a good battery and maintaining it is vital to a comfortable and relaxing trip.

When it comes to batteries then there is one huge consideration that you need to make before looking at anything else and that is whether you are looking for a deep cycle marine battery, a marine starting battery or if you want the best of both worlds by opting for a dual purpose marine battery.

A deep cycle battery is the best for if you want to run your appliances and devices, a starting battery will be able to start up your motor and a dual battery is able to do both. When considering your options here you need to decide exactly what you need a battery for and the storage space that you have available. Having two batteries would give you more options should one of them fail but would naturally take up more space.

Once you have decided what type of battery that you need then there are other things for you to consider as well such as the power that you need from the battery. This depends on the number of devices that you need to run or the size of the engine that you need to start. It’s always important to check your manufacturer’s instructions before you make your purchase to ensure that you are getting a powerful enough battery.

Maintenance of your battery is crucial to making sure that it lasts for a long time, regular checks should be made and the water level constantly checked if you have a flooded battery. When you have a clean and healthy battery you can afford to relax and enjoy what you love whether that is heading out in your kayak or settling down to fish on your boat.

There are three main types of battery available and these vary in quality and price. Flooded batteries are the cheapest but also require the most maintenance and have the shortest lifespan. If you’re working off a budget then this could be the best option for you.

The next level up are gel batteries which don’t require any maintenance and will last for a bit longer and finally there are AGM batteries which are the best available but also the most expensive around. That added price comes with a much more reliable and safe battery, one that doesn’t have to be maintained and one that is resistant to shocks and vibrations. other related articles, best bilge pumps and best marine speakers.

Until they can make a battery that will go on forever, we are left with batteries that will gradually decline over time as they lose their charge. All batteries have a life cycle so it’s important to take care of them and choose the best one to make sure that the battery that you have is going to last for the longest possible time.

Hopefully this buying guide has given you the answers that you were looking for in relation to finding the best marine battery for you. When you’ve picked one, you can sail away on your boat knowing that you have everything under control with a strong battery that won’t let you down. A poor-quality battery can be a huge problem, so make sure you choose the best one to give you the greatest peace of mind.

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Globo Surf Marine Batteries Review

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Found your article while searching for a battery for my boat. Very detailed and informative article.

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My name is David Hamburg. I am an avid water sports fan who enjoys paddle boarding, surfing, scuba diving, and kite surfing. Anything with a board or chance I can get in the water I love! I am such a big fan I decided to start this website to review all my favorite products and some others. Hope you enjoy!