Best Kayak Trolling Motor Battery: 12v Lithium, Inflatable, 80lb Thrust Light
The best portable water vehicle is a kayak, and to make it even faster and more efficient, you can use kayak motors. These motors are powerful enough to speed up your kayak to get you to the target destination quickly. You have to keep in mind that the only power delivery here is a rechargeable marine battery.
If you are running your kayak motor on stock batteries for several months, this a good time to go on a third-party solution as fast as possible.
If you have got the perfect kayak battery on your sailing boat, you are going to the difference in performance immediately. While you are choosing a kayak electric motor battery, you will see many options opening up to you. Let us help you decide what is going to be the best one among all of them.
Reviews of the Best Kayak Trolling Motor Battery
- 1 Reviews of the Best Kayak Trolling Motor Battery
- 2 Best Trolling Motor Battery for 80 lb Thrust
- 3 Reviews of the Best Lithium Trolling Motor Battery
- 4 Buying Guides For The Best Kayak Trolling Motor Battery
- 4.1 The capacity of the battery
- 4.2 Is it made of high-quality lead?
- 4.3 The design language and efficiency of the battery
- 4.4 How big is it?
- 4.5 Battery Life for Kayak Fishing
- 4.6 Cost Comparisons for the Trolling Battery
- 4.7 Are the AGM and gel-cell batteries worth the extra money?
- 4.8 Cost Per Amp Calculation
- 4.9 Is it able to last all day long?
- 4.10 What type of battery is it?
- 4.11 Is it sealed enough?
- 4.12 How long will a trolling motor battery last on a kayak?
- 4.13 What size battery do I need for a 55 lb thrust trolling motor?
- 5 Types of Best Trolling Motor Batteries for Kayak
- 5.1 Lead-acid batteries
- 5.2 Lithium-Ion Battery
- 5.3 How Batteries Work
- 5.4 Understand Basic Chemistry of Kayak Trolling Motor Battery
- 5.5 Voltage
- 5.6 Electrolyte
- 5.7 Recharging of the Batteries
- 5.8 Types of Lead-Acid Batteries
- 5.9 Which is just the right choice as the best kayak batteries?
- 5.10 Construction of the Battery
- 5.11 AGM Tech for Trolling MotorBattery
- 5.12 Wet-Cell Batteries
- 5.13 Gel-Cell Batteries
- 5.14 Absorbed-Glass-Mat Batteries
- 5.15 Which Battery Is Right for you?
- 5.16 Deep Cycle AGM vs. Cranking Batteries
- 5.17 Conclusion
We have selected the most reputable trolling battery brands on the market and also considered some of the models suggested by kayak fishermen.
We have tested them for better reviews, research other reviews on the internet to know exact information on how it performs on kayaks for fishing. After extensive reviews and research, we have come to a list of 7 trolling motor batteries for kayak fishing.
Check them out to choose your best match.
Optima Batteries 8006-006 34M BlueTop – Best for Inflatable Kayak
This is a large marine deep cycle battery that you should see as a professional kayak owner. It is a big 12V battery with immense capacity to deliver power to different devices at once.
This battery is called the best trolling motor battery for 80 lb thrust is the power delivery in any situation. So even if you are in bad weather condition or are at below zero temperature, this battery will give you the best kickup than any other battery in the market.
The outer shell is made of high-quality plastic that will consume the motor vibration easily, and vibration and heavy noise are never going to be a problem for you if you have got this installed. On each battery terminal, you will get separate posts for different purposes. You can still plug this into your other power inverter to power your devices.
The most important thing about this battery is its versatility. This cannot only serve you on the water, and you can still use this in your truck or heavy vehicles. This is going to outperform any other batteries easily.
Has instant power delivery at any weather condition
Has durable and high-quality jacket to keep the vibration low
The overall capacity is impressive, and it can serve you in longer runs
This is a big battery that might not be suitable for small trolling motors
Renogy Deep Cycle AGM – Best Lightweight Trolling Motor Battery
Renogy Deep cycles are the mother of all versatile batteries. It is a big wet battery that has been made with care and built like a waterproof tank. The whole battery weighs about 65 lbs which are light compared to the capacity.
The versatility shines when you plug this in your RV. This shines with the discharge rate. It can discharge at 1100A, which is rated in the spec sheet, and this is why you can use thin to power your vehicle AC and Television if you want to. For kayaks, this is going to be overkill. You will be left an incredible amount of charge left inside this battery after long fishing sessions as well. If you inspect the design, you will see that this is almost a weather-sealed battery that does not let water inside, which is perfect for using in kayaks.
This 100Ah battery is the best trolling motor battery for a kayak that is rated to be a maintenance-free battery. You will not need to charge and discharge it for three months, and the battery will still perform great. In most cases, people discharge and charge their marine batteries every month to avoid decaying.
An entirely maintenance-free kayak trolling battery to use on kayaks and big boats
This is a weather-sealed battery that does not have any effect on water or humidity
Spill-proof battery for long term use
Long service life ensure a long life span
One of the best trolling motor batteries for power
High discharge rate for a wide range of usage
These batteries get a bit hot while charging
Interstate Batteries 12V 35Ah
This is a solid-rated lead-acid battery that has been rated as trolling motor battery. This is not a versatile battery, and it is rated to be used only on trolling motors and other compact power-consuming devices. However, the overall construction seems to the best thing to have in the seas.
This is a compact battery that you can easily carry as you are going for a fishing session. You can both charge this in your house and carry it with you. The 12V and 35 Ah might not be the best thing for a long fishing session, but this will be enough to drive your small and low-power-consuming kayak trolling motors or smaller boat motors than any other conventional batteries.
The concealed outer layer is the thing you should be more concerned about. This is a weather-sealed battery that does not let water inside at any chance. The pole indication is clear, and the connection is clear and straightforward.
The best part you will love about this battery is that this has been made to be more power-efficient and recyclable. In addition, the company recycles the lead that is wastage from trolling motor batteries. This is an outstanding contribution that you can be a part of.
A tiny and compact battery for trolling motors
One of the most reputed choice for trolling the motor market
It comes with better cold-cranking amps
A versatile battery to be charged at any charging spot, including solar power
This is specifically designed for trolling motors
Does not have a huge capacity to drive electricity-driven vehicles or appliances
Odyssey 34M-PC1500ST – Lightweight Marine Starting Battery
Odyssey 34M is a dual-purpose trolling motor battery that you can also use as a marine battery. This is the best kayak trolling battery that has incredible power capacity and high Ampere output. You can use this battery in your RV and other recreational trucks as well if you want to.
This is a dual-purpose battery that has been made in the USA. The maximum product quality can be seen here. The internal is as good as the outer layer can be seen. The outer layer is smooth finished, which ensures that weather is not becoming a problem while it is on your kayak in the long run.
The overall capacity is good enough to run for a whole day fishing or kayaking around. You can manage to connect a GPS-based trolling motor that constantly consumes energy from batteries. The deep cycle feature will ensure that you can use your battery for longer without losing any capacity over extended charging and discharge cycles.
As you unbox this battery for the battery box, you will find out that the posts are covered by a plastic cap. The dual pole system is plated with tin so that corrosion never becomes a problem.
This battery does not have a performance drop even after one hundred battery cycles.
A high capacity battery with a dual purpose of use
It comes with long service life for the kayak angler
The correct battery for longer marine use with better amp draw
This battery feels very high quality from the outer shell to the inside
The battery performance drops after about three hundred charge cycle
Best Trolling Motor Battery for 80 lb Thrust
Within the last few years, I have seen what could be the answer to the battery prayers of many owners whose kayak’s trolling are not clear candidates of either pure cranking batteries or pure marine deep-cycle AGM batteries. These batteries can put up to 80 lb thrust with low battery consumption.
Previously owners of these borderline trolling motors were forced to choose between two imperfect options.
We now have batteries advertised as combination cranking/ deep-cycle units that are a perfect solution for the weekend powerboater who occasionally spends the night camping or fishing at anchor and spends the rest of the time at the dock plugged into shore power.
These 80lb thrust power batteries offer a powerful capacity in performance. However, they won’t be as capable of sustaining repeated deep discharging and recharging as an actual deep-cycle AGM battery. Still, they will be acceptable for occasional deep-cycle use and more than adequate for starting your engine. So let’s Checkout the reviews of these powerful batteries:
Optima OPT8016-103 Trolling Motor Batteries
In this section of the best trolling battery for 80 lb thrust, Optima is the number one popular choice for all professionals worldwide. This is made just like the other optima battery options we mentioned no the first place. But this one has slightly better power reservation, and the overall power delivery is around 55Ah. The overall weight is also larger than the last one.
The most exciting part about these optima batteries is the pure lead inside. The lead used in these batteries is high quality. Due to not having any kind of impurity, these batteries can give you the thrust you need.
You will quickly get a thrust of about 90 lbs if you have the perfect motor on your inflatable boat. There is no power loss or slow power delivery throughout the whole discharging process until it reaches around 20 percent of capacity.
The cylindrical design is the best thing about these trolling motor batteries. This makes the whole thing small as a compact battery. The concealing is also great, and it does not get through any trouble even after the intense vibration of motors or vehicle engines.
Well thought internal design to keep everything safe and efficient
Optima batteries come with dual posts for multipurpose usage
Pure materials inside serve an uninterrupted performance to your engine
Optimal 870 ampere is excellent for trolling motors
One of the best starter battery options for a double and single charge
This is a heavy battery to use on a small kayak
VMAX MR127 12 Volt 100Ah AGM Battery
VMAX MR127 is a huge marine deep cycle battery that you can call the best 12v lithium battery for a kayak. This battery has a massive 100 Ah power capacity which is incomparable to all other options in the market. This is not only a battery for kayaks; this can also be used on big boats like yachts as well.
While you are purchasing the battery, you will see that this is made especially for boats, and the deep cycle feature will be perfect for long-lasting stable performance.
The most exciting fact about this battery is that it is an AGM battery. AGM batteries are good at sitting at a place for longer and still do not let the performance decay too fast. So you can sit relaxed for months without worrying about maintenance at all.
This is a big battery with a big punch, and You can even use this battery on Heavy RVs and even on home power supplies. For carrying this considerable battery, there are foldable handles built on the upper part of the battery.
Poles have nuts that you can tighten up to be used in rough and challenging situations.
The capacity is around 100 Ah which is huge compared to other compact batteries
The AGM technology lets the battery sit for months without maintenance
Best battery for kayak fishing trolling
This is a 100lb battery that is not good for the portability and stability of your kayak
Reviews of the Best Lithium Trolling Motor Battery
These are the most advanced batteries of all. Li-ion has highly reactive chemicals inside that provide extreme power delivery despite having a minimal form factor. In addition, lithium batteries are smaller than most of the batteries out there.
The power delivery and capacity are insane in these batteries. So engineers install particular kinds of power management circuits inside these batteries so that they become more efficient.
The main drawback would be the lack of price range. Li-ion battery price can go as double the AGM batteries. You will also have to be careful when you are charging your li-ion batteries.
Here are the reviews of the best li-ion batteries for use with kayak trolling motors.
Battle Born LiFePO4 Deep Cycle Battery – Best Kayak Lithium Battery
This part of the review will see the best lithium-ion battery with excellent power delivery on a very small and lightweight form factor. Battle Born LiFePO4 is the perfect lithium-ion battery for trolling motors and vehicles you will find at this price range.
If you compare this with other batteries here, this is different. Unlike other batteries, this has more circuits inside. These circuits are going to control and manage the power delivery for optimal stability and lengthy battery life.
This circuit will shut the power off and even act as a security ad safety mechanism to prevent any damage to your motor or battery. This circuit is also going to ground protect your battery in case it shorts out. This is an outstanding feature that any beginner must-have. Charging these li-ion batteries is also a fast process that takes the compatibility further.
The versatility of this battery is also worth mentioning. This ability to push current at 100 amp speed. This is going to be enough to power your trailer electronic or even your off-grid appliances on RVs.
Li-ion technology is a one step ahead efficient battery technology
Small and compact form factor compared to lead-acid options
Fast charging speed and reliable power delivery
It comes with a ten years warranty
You will need different and better power supplies to charge this battery which will be expensive.
Banshee Deep Cycle Lithium Marine
Banshee is another li-ion battery with more features added with efficient battery technology. This not only has a li-ion battery with a lot of circuits to manage efficient power delivery, but this also has a small digital indicator display to show the power it can provide through the pole.
This battery is the best choice if you are kayaking at a very low temperature, even at temperatures below zero degrees. At a very low temperature, this can power your kayak motor with instant thrust. The 1200 CCA indicates the initial engagement of all the cells inside the li-ion battery. This deep cycle battery has an extended power-saving reserve capacity that enables low discharging on more prolonged idol states than most deep cycle AGM batteries.
To connect more accessories and gadgets with this battery, you will find two poles on this battery. So this is a versatile choice with more compatibility. The weather sealing is like no others in the market. This will get wet, and you should not be worried about getting it damaged.
This battery even comes with three years of warranty. SO you will not have to worry about getting it replaced for a long time.
This battery has voltage indicating display on the top
Relatively lightweight when compares with its competitors
It has high cranking power, which is 1200CCA at a very low temperature
Better cold-cranking amp with better amp-hour
Good for fishing in shallow water and cold temperatures
It is made of premium materials with top of the line technologies cramped inside
This is an expensive battery
Best 12v Lithium Battery for Trolling Motor – Mighty Max 12V 35AH
If you want to go super heap on kayak trolling batteries, this is a perfect choice for you. The overall capacity of this battery is around 35 Ah, which is enough for you to cover short fishing sessions. However, you might find a bit low performance in low battery situations because of the low reserve capacity. But you have to keep in mind that this is a fast-charging battery that will not take more than three to four hours to charge it up entirely.
Because of the size, you can store this small and compact mighty max battery 12v battery in your motorized kayak chamber quickly. for the size and convenience, this is the best lithium battery for a kayak trolling motor. YOu can charge it up while it is not on your kayak. To carry the whole thing, it has handles to carry the whole thing away.
The incredible thing about this small battery is the technologies inside. This is a capable deep cycle marine battery that can sit on your boat for a long time without charging and even without any maintenance. Make sure you are also getting an excellent portable battery charger to pair this up with.
A small and compact battery to have on kayaks
Perfect for smaller trolling motor for fishing trips
This is a Sealed Acid battery that does not require any maintenance
This a very cheap battery to have as a second power source
This battery that not have initial kicks to power start your kayak engines
Best Battery for Minn Kota Trolling Motor – Universal Power Group 12V
In our final choice, we have a universal battery from UB. The price point is insanely cheap. Regardless of the price point, you can use this universal battery anywhere you want to. This is just like the mighty max battery we mentioned before. The only difference you will find here is the capacity which is 100Ah.
This mighty max battery powers up motors very quickly, and this is also usable on off-grid appliances. You can install this battery inside your yacht boats as well. It will power up your microwaves, fridges with no hiccups.
As this battery is sealed and maintenance-free, you should replace these trolling motor batteries after two to three years of heavy usage. You will not have to take care of any acid and water change in the meantime.
As these batteries are super cheap and affordable, you might not expect too much strength and shock absorption from them. But this battery will last a long good time by absorbing shocks and vibration from motors and generators.
A cheap universal battery to install on your car and vehicle
Don’t have any problem leaking battery acid
This mighty max battery 12v holds up to 100Ah DC power which is enough for heavy vehicles.
This battery does not need support during the performance and hibernation period
The overall quality is not that satisfying, and premium
Buying Guides For The Best Kayak Trolling Motor Battery
The min power source of your trolling motor is the trolling motor battery. This is the most significant part of your fishing kayak. It will deliver the thrust of power to your trolling motor, and you can also connect other additional gadgets with it if you want to.
Before you decide which one is the best lithium trolling motor battery, you must consider several things which we will mention in this part of the review.
The capacity of the battery
The first thing you will have to look at is the capacity. You have to make sure that you do not lack capacity while sailing for further distance coverage. The total capacity of a battery will be determined by Ampere Hour (Ah). The higher this number will be, the larger the conventional battery capacity will be from the larger batteries.
If you have gone through our recommendations, you will see that as the battery capacity increases, the size of the battery increases as well. Li-ion kayak trolling motor batteries are still compact size if you compare this to L-acid batteries. As kayaks are small boats, you have to make sure that you are not overweighting your kayak and it is on balance.
Is it made of high-quality lead?
The most common type of battery you will find in the market is lead-acid type batteries. However, while you choose the battery, you should keep in mind that the battery has to have high-quality materials built-in.
The purity of the lead used in the battery will determine how smooth the power delivery is. So before you purchase, make sure that the lead is pure and does not interrupt delivery through the lead plates.
The design language and efficiency of the battery
The internal design of the battery will also affect the overall performance of the battery. Regular lead-acid-type batteries are not going to be the most convenient option here. You have to look for AGM batteries in this case.
AGM batteries are water-sealed. These kayak trolling motor batteries are also maintenance-free. You will not have to take care or even change the battery acids in years, and these batteries will run smoothly.
There are twisted lead designs as well. We mentioned two of those batteries here. These batteries have more lead than acids. You will get good kicks out of them. You have to research the performance delivery according to the internal design of the battery.
How big is it?
It is known to all that the bigger, the better. The battery you purchase has to be able to fit inside your kayak battery chamber. Generally, kayaks are small and meant to be used for lightweight battery components. A 100Ah battery will weigh around 50 to 60 lbs which is heavy. You have to make sure that your kayak can carry them out while you are on board.
Battery Life for Kayak Fishing
But what about charging cycles? How many times on average can the different types of batteries be discharged and recharged before they need to be replaced?
This is a difficult question because the number of charging cycles that you can expect out of a battery depends upon the rate and depth of discharge, the recharging method, and the quality of the battery construction.
Also, the rechargeable battery options of the same nominal size will often have different amp-hour capacities, and the real concern is the cost per amp-hour.
The Typical Battery Charging Cycles table above represents the average number of times top-quality batteries of each type can be discharged and recharged. Cheap substitutes will provide a much lower average number of cycles.
Cost Comparisons for the Trolling Battery
Conventional wet-cell battery is the least expensive of the three types we have discussed, no matter which way the cost is measured. So the question is, if I buy the new gel-cell or AGM batteries, what am I getting for my extra battery dollars?
Are the AGM and gel-cell batteries worth the extra money?
The answer is that there is no answer, at least not one that fits all circumstances. The type of battery that’s best for you depends on your needs and the use to which you put your boat. Here are some cost comparisons.
Comparing charging cycles to the typical costs per battery gives you a feel for the actual cost of these batteries over the long haul. For example, using a group 27 battery (a standard size) for comparison gives a cost-per-cycle based on the average number of cycles in each type used above.
The table below compares specific group 27 deep cycle battery prices taken from the 1998 West Marine catalog and the average actual cost per cycle.
Cost Per Amp Calculation
Using a cost-per-amp-hour calculation, we can use the advertised total battery amp-hours capacities for the three group 27 deep cycle trolling batteries West Marine lists in the same 1998 catalog to arrive at the cost over the battery life (see table on the next page).
Please keep in mind that these costs are based on charge-cycle numbers that are pretty high. In actual use, your cost per amp-hour will probably be much higher. However, on average, the findings here are as good for comparing battery types as any other method.
Although they will require more maintenance than other types, conventional wet batteries are still the least expensive of the three types to buy and own over the long haul. This is because AGM batteries offer all the advantages of the gel-cells plus a less-finicky charge cycle.
Therefore, in almost all applications, AGMs are a better choice than gel-cells, but as of this printing, you’ll still pay a substantial premium for AGMs over wet-cells.
AGMs are an excellent choice for installations where acid spills are considered, as with personal watercraft (jet skis) and other sport kayaks. In addition, they are excellent for use on boats that will be left unattended for months at a time.
Is it able to last all day long?
The longevity of a battery will be determined by how much battery power this can store inside the battery. The higher the Ah is, the longer it is going to last. The lasting time will also depend on your trolling motor.
You must calculate the current drawing from the batteries by the motor you have installed on your boat. If you are using a trolling motor with many features built-in, that might be a significant current drawer. So be wise while you choose the battery for trolling the motor all day long.
What type of battery is it?
By the passage of time. There had been a lot of researches about batteries, and from traditional lead batteries, we have come to a point where we don’t have that many batteries that need maintenance. So we will be talking more about different types of batteries in this article here.
We mainly have lead-acid types of batteries and li-ion batteries. Li-ion batteries are one step ahead of the technology. These are also low-maintenance batteries that will be easy to manage. But there are pros and cons to all types of batteries.
Is it sealed enough?
Weather sealing will be the most important priority here. As you will be taking these batteries in the water to troll your boat around, there will be chances that batteries will get for sure. So you just have to make sure that those batteries on your boat have good water sealing. Excellent water sealing will ensure that these batteries internal do not get in contact with the water anyhow.
Most of the batteries we mentioned in this review have excellent water sealing, and they are suitable to be used as marine batteries.
How long will a trolling motor battery last on a kayak?
There is no correct answer to this question here. This is a dynamic question where all these things relate to the load you have on your marine battery. Generally, the primary source to draw the most energy from the battery is the rolling motor. So before you calculate, you have to know the overall wattage of the electric trolling motor.
We have a formula that is going to make things easy for us. You have to multiply the Ah rating on your battery by 10 and divide the number you get with the wattage of the motor or the appliances you have on your boat or vehicle. The result will take the hours this battery is going to last.
The result you get from this calculation is a hundred percent efficient. It is assumed that no energy is being lost here. The motor is a hundred percent efficient here. Be sure that the actual lifetime of the battery will be at least an hour less than that because of a lot of parameters.
What size battery do I need for a 55 lb thrust trolling motor?
If you are looking for the best battery for Minn Kota trolling motor with a 55 lb burst, you should choose a battery like Minn Kota endura batteries that can give you the instant thrust it needs. You should look for a battery that has a capacity of over a hundred to 150 Ah rating. You can still power your motor and get Kota thrust, but you will no9t get the thrust at an instant, and if the motor cannot work at its full advantage, there will be power loss and power wastage.
Types of Best Trolling Motor Batteries for Kayak
The main feature that matters as a trolling motor battery is that the battery has to be a deep cycle battery. Most of the batteries that are recommended or rated for trolling motors are deep cycle AGM batteries. The main difference you will see in those batteries is how they are built and what chemical materials are in those batteries.
According to our research, it can be ensured that there are mainly two types of batteries that you can buy. The first one is the conventional lead-acid with AGM technology. The other one is the Li-ion batteries.
If you consider the price, these are the most affordable batteries to use for trolling motors. You can easily find a battery that produces power by converting chemical energy into DC electricity. You can easily find a 100Ah battery within a hundred dollars. The main drawback you will have to face is the weight. These are the heftiest batteries of all. As you are buying trolling motor battery for kayaks, you have to make sure that your boat can carry it safely.
If you look deeper into the choices, you will find out that some of the batteries have an AHM rating. Those are also called AGM batteries. AGM stands for Absorbant Glass Mat. These batteries are not that affordable in the price range, but the main feature that will help you with kayaks is the maintenance-free life. These batteries are going to last several years without changing any chemical or even any maintenance.
Lithium-ion batteries are smaller than engine start batteries, allowing the current to be released more slowly but over a more significant period. As a result, these cells are best for portable rechargeable batteries.
This means they can be used for applications such as small portable devices, cameras, torch lights. But new modern technologies have improved, and now they are bigger and better. For example, they can be used with kayak motors of electric wheelchairs and golf trolleys.
Not only the slow power, but as they are also capable of producing the short burst of power required for engine starting, they are well-suited for use in caravans, motorhomes, and boats.
They are generally slightly more extensive and expensive than engine start batteries and can usually be maintained by removing their cell covers and topping up with water as necessary.
Lithium-Ion batteries are the type used on forklift trucks. They are designed for very heavy deep cycle use, but they are also suitable for regular use for engine starting.
In any case, they require charging at higher voltages than can usually be achieved by an alternator and are available only as individual 6 volt or 12-volt battery cells. In addition, building a bank of cells to create a battery of the required voltage results in more expense, weight, and size.
How Batteries Work
The Basics In direct defiance of the wishes of one of my editors, I have decided to avoid a long dissertation on the chemistry that boils between the plates of your boat’s batteries. For one thing, battery chemistry is a complicated subject that would take many pages to discuss appropriately. And for another thing, it’s not what this book is about.
I want you to know how the electrical system on your boat works and what to do when it doesn’t. The internal chemistry of the battery just isn’t that important.
However, for your technophiles who do want to delve deeper into the chemical mysteries of the modern voltaic storage battery, I would refer you to your public library and the Encyclopedia Britannica, where you’ll find an exhaustive (and exhausting) article on the subject.
Understand Basic Chemistry of Kayak Trolling Motor Battery
Unfortunately, I am not going to avoid chemistry altogether, and there are a few underlying principles with which you should be familiar. But, for our purposes, it’s enough to know that the several types of storage batteries you might find on your kayak all work on the same system.
Batteries are divided into cells with plates of two dissimilar metals surrounded by an electrolyte. An electrolyte can be any electrically conductive material (electrolytes are an essential component in popular energy drinks like Gatorade). When any two metals are suspended in it, they will produce an electrical voltage between them.
(Voltage, you’ll remember, is the potential to produce electrical current, and thus, is the only electrical value that’s static.) Therefore, the magnitude of the voltage will always be different for different combinations of metals and electrolytes.
The electrolyte used in your kayak’s batteries (as well as in your car batteries) is sulfuric acid, and the dissimilar metals are lead dioxide in the positive plate (or cathode) and sponge lead (a porous form of pure lead) in the negative plate (or anode). Thus, all such batteries are called “lead-acid” batteries.
As a lead-acid battery is discharged, the acid electrolyte is chemically converted to water (this explains why batteries can freeze and why the specific gravity changes, all of which we will cover later). The plate material is converted to lead sulfate.
Recharging of the Batteries
To recharge a battery, you pass through it a 12-volt charge that converts the three active materials back into their original state. The actual chemical formula for this process, when set in 10-point type, is some 4 inches long, which is why I decided not to go into it any deeper than we have just done.
The only other ingredients in your kayaks or boat’s engine or electric trolling batteries are the grid, an inert (plastic) frame on which the solid active ingredients are suspended in the electrolyte, and the case. Unfortunately, lead dioxide, sponge lead, and lead sulfate are all very soft and fragile.
The grid gives the plates the support they need to stand up to vibration and shock. The case, of course, contains the entire contraption and insulates one cell from the next.
The voltage from a single cell in a fully charged lead-acid battery will always be approximately 2.1 volts (called the galvanic potential), regardless of the size of the battery. So a sealed lead-acid battery the size of your house will produce the same voltage as one the size of a peanut.
Thus, when six of these cells are strapped together in series (positive to negative and negative to positive), you have a standard 12-volt battery.
Recent engineering innovations have allowed manufacturers to produce slightly thinner plates than their predecessors but just as electrically capable. And due to advances in material technology, the new plates are much stronger than the old ones.
Types of Lead-Acid Batteries
There have been enormous advances in kayak trolling motor battery technology in the past few years. The result is a large and growing assortment of batteries that you can use on your boat and most kayak trolling motors. The days of the massive black case with gooey sealer and exposed lead cell-connecting bars are fading into history.
Many heavy-duty commercial batteries are still constructed traditionally, but things are changing fast even here. We now have low-maintenance, no-maintenance, cranking, deep-cycle, gel-cell, AGM, standard automotive, and even special golf-cart batteries.
Which is just the right choice as the best kayak batteries?
Well, that depends on what you’re going to do with the battery once you buy it. Today, many boats and watercraft (small watercraft or large) will have at least two battery-type options on board, and some will have more than that.
To start, we can eliminate the standard automotive battery from all but incidental marine applications. These batteries might look just like their marine counterparts, but they are very different. Automotive batteries, even the so-called heavy-duty ones, are lightly constructed with thin plates hung on fragile grids; even the cases are thin plastic.
Construction of the Battery
This is because your automobile just doesn’t need a big, heavy battery. Your kayak, however, does need a big, heavy battery, and car batteries wouldn’t last very long in the marine environment.
Marine batteries must stand up to the vibration and profound states of discharge common on boats, and they must be able to withstand levels of neglect and abuse to which you would never subject your car battery.
The difference between batteries is not only in the physical construction but also in the ratios of lead peroxide and other materials such as antimony and a calcium alloy used in constructing the battery’s plates and the amount of material used in the plates.
These variations affect how a kayak trolling motor battery can be cycled (the number of times a battery can be discharged and recharged) and still come back to practical life.
The construction of a battery also affects how long it can remain discharged before the lead sulfate hardens to the extent that recharging can’t reverse the chemical reaction. When this happens, the battery is said to be sulfated and must be replaced.
These chemical and construction variations in basic battery types also explain why some batteries tend to produce more hydrogen (a process called gassing) than others.
AGM Tech for Trolling MotorBattery
Engineers have been able to reduce gassing to almost nothing by adding antimony into the plate material. Minor gassing means less water loss, and hence the evolution of the sealed batteries is becoming the norm today.
We now enjoy modern gel-cell or absorbed-glass-mat (AGM) technologies that keep the sulfuric acid in either a gelled state or absorbed in a mat material, much like conventional dry-cell batteries.
The first essential choice you’ll have to make as you try to pick out a battery for your inflatable kayak is between the old-technology wet cell batteries, the new gel-cell batteries, and the even newer AGM batteries, so let’s take a close look at each of these three.
Wet cell battery technology has been around since the days of the first electric-start automobiles. This is the type of battery with the removable cell caps (generally, but not always) with which we are all familiar because it’s the type still found under the hood of the family car.
Wet cells have the lead plates suspended in a liquid electrolyte, and the durability of the individual batteries depends on the robust construction of the case and grids and the amount of material in the plates.
Even today, wet batteries offer some crucial advantages over gel-cell and AGM batteries, the new kids on the block. They are usually the cheapest to buy initially and, as we will see below, they are by far the cheapest to use over the long haul-provided, of course, that you don’t neglect regular maintenance. They also stand up well to abuse, such as overland undercharging.
The disadvantages of wet cells are that they require more elaborate ventilated battery compartments. They will not hold a charge as long as the newer gel cells and AGMs, which means that they can’t be left unattended for as long. They must be kept upright at all times, and they require regular topping-up with distilled water.
Gel-cell batteries work on the same principles as wet cells, and the materials are the same. The big differences are that the electrolyte is rendered into a paste about the consistency of grape jelly, and the plates (which have a slightly different composition, to reduce gassing) are suspended in this goo. Also, since there is no liquid to top up, there is no need for the familiar caps, and the cells are sealed for all practical purposes.
There are several important advantages to gel-cell batteries. You don’t have to worry about spilling the electrolyte by tipping the case over, for one thing. Gel cells work just fine on their sides or even upside down. In addition, they hold a charge much better than wet cells and can be left unattended for longer periods, and, of course, you don’t have to worry about topping up the electrolyte.
Besides the cost (which we will go into below), the disadvantages of gel-cells are that they cannot be overcharged without suffering permanent and often terminal damage. Also, because the electrolyte can’t circulate between the plates the way it can in a wet battery, gel-cell plates must be kept thin enough to accept a charge in a reasonable length of time.
Generally, over the last five years, gel-cells have developed quite a bad reputation for not living up to the claims made for them by manufacturers. Moreover, gel-cells have charging needs that differ from both the AGM (which we will discuss next) and wet batteries.
Traditional constant-rate Ferro-resonant battery chargers found on all older boats and on new high-production kayaks (Sea Ray and By-liner, to name two) have destroyed many gel-cell batteries. So instead, Gel-cell batteries must be charged using a three-stage smart charger with the voltage set for the gelled electrolytes.
Absorbed-glass-mat batteries are also of the no maintenance type. They have a sealed case, just like their gel-cell cousins: you couldn’t add water to these batteries if you wanted to. The primary difference between AGM batteries and gel cells is in the way the electrolyte is supported.
AGMs have a fiberglass mat between the cells that further supports the electrolyte. There are other important differences, though. For example, tests have shown that AGMs are less sensitive to charge rates than gel-cells, perhaps making them a better choice if you own an older boat with a constant-rate charger.
Which Battery Is Right for you?
All but the smallest open boats should have at least two batteries. The starting battery is for starting the engine and needs a lot of cranking capacity to spin a heavy-duty starter motor.
The house battery is used to run equipment such as cabin lights, stereos, refrigerators, and electronic equipment connected to the engine. The starting battery should be a heavy-duty marine cranking battery, and the house battery should be a deep-cycle marine battery.
One of my kayaks, a 15-foot dory I use for bay fishing, has a single deep-cycle AGM battery that I use to operate my fish-finder and running lights at night. The engine is a pull-start outboard, so I don’t need a cranking battery. If I had an electric-start engine on this boat, I would consider an additional cranking battery, even for a boat this small. I hate paddling; it just takes too long against a two-knot tide.
My other power kayak’s trolling, a 25-foot V8-powered walk-around, is set up with a group 27 cranking battery and a group 27 deep-cycle marine battery.
Deep Cycle AGM vs. Cranking Batteries
The difference between cranking and most deep cycle batteries is simple. Cranking batteries are designed to provide a burst of cranking amps power for a short period. Once the engine is running, the engine’s alternator will kick in and quickly recharge the trolling motor mount battery, replacing the power used to start the engine.
Cranking batteries are not designed to be discharged deeply over and over again. You would be lucky to get one season of kayak trolling out of a cranking battery used as a deep-cycle house battery.
On the other hand, deep-cycle motor batteries are built with heavy and comparatively thick plates and have much more lead in them than cranking batteries. You can tell the difference between the two by lifting them.
They are designed to be discharged up to 50 percent of capacity and repeatedly recharged without sustaining any permanent damage. However, the heavier and thicker plates used in deep-cycle cells take much longer to reach full charge than cranking batteries. Therefore, they aren’t a good choice for a starting battery for extra trolling with optimal starting power, particularly where an engine will be started frequently and run for short periods.
Deep-cycle batteries for most trolling motors are perfect for use as the house battery in cruisers that will be anchored away from shore power for overnight trips or FNG boats anchored for long periods with the fish-finder, radio, and beer cooler running.
Deep-cycle batteries are designed to take abuse, but even these can’t be discharged entirely and recharged continually without failing. Thirty percent of total capacity is generally considered a maximum level to which these batteries can be safely discharged. However, fifty percent maximum discharge provides a significant increase in the life of the motor mount battery.
It is fair enough to say that this is a world to get confused by the battery choices we have in front of us. But, as we are going forward and leaving behind those diesel and gas-operated motors and depending on the green electricity power, we also have to stay a step ahead.
Whatever you are buying from the market, make sure that you are buying t from a good company. See if the company is depending on recyclable materials and they are concerned about efficiency and nature. Do not go cheap if you find anything fishy going with the battery manufacturer.