Trolling Motor Battery Size (Guide) in 2024

Have you ever wished you could kayak faster and farther without paddling? If so, you might want to consider getting a kayak trolling motor. A kayak trolling motor is a small electric motor that attaches to your kayak and propels it through the water. It can make your kayaking experience more enjoyable and convenient, as you can save your energy, explore more areas, and focus on fishing or sightseeing.

However, before you buy a kayak trolling motor, you need to know what size battery you need to power it. The battery size depends on several factors, such as the thrust, speed, and duration of your motor. In this article, we will explain how to choose the right battery size for your kayak trolling motor.

We will also review the different types of batteries, such as lead-acid, lithium-ion, and lithium-iron-phosphate, and compare their advantages and disadvantages. By the end of this article, you will have a better idea of what size battery for trolling motor you should get for your kayak.

Importance of Choosing the Right Battery Size

Choosing the right battery size for your kayak trolling motor is crucial for ensuring optimal performance and efficiency. The battery size determines how long and how fast you can run your motor without draining the battery. The battery size depends on several factors, such as the thrust, speed, and duration of your motor. The thrust is the force that the motor exerts on the water to move your kayak.

The speed is the rate at which your kayak moves through the water. The duration is the time that you want to run your motor continuously. These factors affect the battery capacity, voltage, and current that you need for your motor. The battery capacity is the amount of energy that the battery can store and deliver. The voltage is the electrical pressure that the battery provides to the motor.

The current is the rate of flow of electricity from the battery to the motor. Different battery sizes have different capacities, voltages, and currents. For example, a 12-volt battery with a 100 amp-hour capacity can run a 30-pound thrust motor at a low speed for about 10 hours, while a 24-volt battery with a 50 amp-hour capacity can run the same motor at a high speed for about 5 hours. The battery size also affects the weight and balance of your kayak, which can influence your stability and maneuverability.

Therefore, you need to choose a battery size that matches your motor specifications and your kayaking needs. A general formula for calculating the battery size is to divide the motor’s amp draw by the battery’s amp-hour rating and multiply by 100. This will give you the percentage of battery life that you will use per hour. For example, if your motor draws 20 amps and your battery has a 50 amp-hour rating, then you will use 40% of your battery life per hour. You can then estimate how long your battery will last based on your desired duration.

Factors to Consider When Determining Battery Size

The battery size for your kayak trolling motor depends on several factors, such as the thrust, speed, and duration of your motor. The thrust is the force that the motor exerts on the water to move your kayak. The speed is the rate at which your kayak moves through the water. The duration is the time that you want to run your motor continuously.

These factors affect the battery capacity, voltage, and current that you need for your motor. The battery capacity is the amount of energy that the battery can store and deliver. The voltage is the electrical pressure that the battery provides to the motor. The current is the rate of flow of electricity from the battery to the motor. For example, if your motor has a 30-pound thrust and draws 20 amps, you will need a 12-volt battery with at least a 40 amp-hour capacity to run it for two hours. You can use the formula: battery capacity = motor amp draw x duration / 0.8, where 0.8 is a safety factor to account for battery inefficiency and discharge.

However, the battery size also affects the weight and balance of your kayak, which can influence your stability and maneuverability. Therefore, you should choose a battery size that is not too heavy or bulky for your kayak. You should also consider the cost and availability of different battery sizes and types, as they can vary widely depending on the brand and quality.

Understanding Battery Capacity and Amp Hours

The battery capacity is the amount of energy that the battery can store and deliver. It is usually expressed in watt-hours (Wh), which is the product of the battery voltage (V) and the battery amp hours (Ah). The battery amp hours (Ah) is a measure of the electric charge that the battery can hold. It is the amount of current (in amps) that the battery can provide for one hour.

For example, a 12V battery with a 100Ah capacity can store and deliver 1200Wh of energy. This means that it can supply 12 amps of current for 100 hours, or 100 amps of current for 12 hours, or any combination that equals 1200Wh. Similarly, a 24V battery with a 50Ah capacity can also store and deliver 1200Wh of energy, but it can supply 24 amps of current for 50 hours, or 50 amps of current for 24 hours, or any combination that equals 1200Wh. A 48V battery with a 25Ah capacity can also store and deliver the same amount of energy, but with different current and time values.

The battery capacity depends on several factors, such as the temperature, age, and discharge rate of the battery. Higher temperatures, older batteries, and faster discharge rates can reduce the battery capacity and shorten the battery life. Therefore, it is important to choose a battery size that matches your motor specifications and your kayaking needs, and to maintain your battery properly.

Formula:

Average current draw (in amps) = Thrust (in pounds)×12​ ÷ Voltage (in volts)

For example, if you have a 12V motor with a 55-pound thrust, the average current draw of your motor is:

1255×12 ​= 55 amps

You can estimate the battery capacity you need for your trolling motor by using the following formula:

Battery capacity (in Ah) = Average current draw (in amps)×Desired run time (in hours) ÷ Discharge rate (in percentage)

The discharge rate is the percentage of the battery capacity that you can use before the battery voltage drops below the minimum level required by the motor. The discharge rate depends on the type and quality of the battery, but a common value is 50%. For example, if you want to run your motor for 4 hours with a 55-amp current draw and a 50% discharge rate, the battery capacity you need is:

0.555×4 ​= 440 Ah

This means you need a 440 Ah battery to run your motor for 4 hours. However, this is a theoretical value that does not account for other factors, such as the temperature, the condition of the battery, and the efficiency of the motor. Therefore, you may want to add some extra battery capacity to account for these factors and to extend the life of your battery. A good rule of thumb is to add 20% to 30% more battery capacity than the calculated value. In this case, you may want to choose a 550 Ah or a 600 Ah battery for your trolling motor.

Different Battery Sizes and Their Applications

There are different battery sizes that you can choose for your kayak trolling motor, depending on your motor specifications and your kayaking needs. The most common battery sizes are 12V, 24V, and 48V, which have different capacities, voltages, and currents. The capacity is the amount of energy that the battery can store and deliver, measured in watt-hours (Wh) or amp-hours (Ah).

The voltage is the electrical pressure that the battery provides to the motor, measured in volts (V). The current is the rate of flow of electricity from the battery to the motor, measured in amps (A). For example, a 12V battery with a 100Ah capacity can store and deliver 1200Wh of energy, and can supply 12A of current to a 12V motor. A 24V battery with a 50Ah capacity can also store and deliver 1200Wh of energy, but can supply 24A of current to a 24V motor.

A 48V battery with a 25Ah capacity can also store and deliver the same amount of energy, but can supply 48A of current to a 48V motor. Each battery size has its advantages and disadvantages, such as the weight, cost, performance, and compatibility with your motor and kayak. A 12V battery is the lightest and cheapest option, but it has the lowest capacity and voltage, which means it can only power a low-thrust and low-speed motor for a short time. A 24V battery is a medium option, which has a higher capacity and voltage, which means it can power a medium-thrust and medium-speed motor for a longer time.

A 48V battery is the heaviest and most expensive option, but it has the highest capacity and voltage, which means it can power a high-thrust and high-speed motor for the longest time. The battery size that you choose depends on the application and scenario that you want to use your kayak trolling motor for. For example, if you want to kayak in calm and shallow water, for a short distance and a low speed, you can use a 12V battery with a low-thrust and low-speed motor.

If you want to kayak in rough and deep water, for a long distance and a high speed, you will need a 48V battery with a high-thrust and high-speed motor. If you want to kayak in moderate and variable water, for a medium distance and a medium speed, you can use a 24V battery with a medium-thrust and medium-speed motor.

How to Calculate the Battery Size For Your Trolling Motor

To calculate the battery size for your trolling motor, you need to know the motor amp draw, the duration, and the battery capacity. The motor amp draw is the amount of current (in amps) that the motor consumes from the battery. You can find the motor amp draw on the motor specifications or the manufacturer’s website. The duration is the time (in hours) that you want to run your motor continuously.

You can estimate the duration based on your kayaking plans and preferences. The battery capacity is the amount of energy (in watt-hours or amp-hours) that the battery can store and deliver. You can use the following formula to calculate the battery capacity: battery capacity = motor amp draw x duration / 0.8, where 0.8 is a safety factor that accounts for the battery inefficiency and discharge. For example, if your motor has a 30-pound thrust and draws 20 amps, and you want to run it for two hours, you will need a battery capacity of at least 50 amp-hours (20 x 2 / 0.8 = 50).

You can then choose a battery voltage that matches your motor voltage, such as 12V, 24V, or 48V. The battery voltage determines the battery size and weight, as well as the motor speed and performance. For example, a 12V battery with a 50Ah capacity will weigh about 30 pounds and will run your motor at a low speed, while a 24V battery with a 50Ah capacity will weigh about 60 pounds and will run your motor at a high speed.

The formula for calculating the battery size is a simple and useful tool, but it has some limitations and assumptions. It assumes that the motor amp draw is constant and does not vary with the speed, load, or water conditions. It also assumes that the battery is in good condition and does not lose capacity over time or due to temperature, age, or discharge rate. It also does not account for the environmental factors that can affect the battery performance, such as the wind, waves, current, and drag. Therefore, you should use the formula as a guideline and not as a rule, and always have some extra battery capacity as a backup.

Best Trolling Motor Battery Sizes For Different Boat Types

The best trolling motor battery size for your boat depends on the size of your boat and the thrust of your trolling motor. The boat size determines the weight and length of your boat, which affect the amount of force and speed that you need to move your boat through the water. The trolling motor thrust is the force that the motor exerts on the water to propel your boat. The battery size determines the capacity, voltage, and current of your battery, which affect the performance and efficiency of your motor. Generally, the larger and heavier your boat is, the more thrust and battery power you will need to run your motor. Conversely, the smaller and lighter your boat is, the less thrust and battery power you will need. Here are some general recommendations for the best trolling motor battery sizes for different boat types, based on their weight and length:

Boat Type	Boat Weight	Boat Length	Trolling Motor Thrust	Battery Size
Small	Less than 2,500 lbs	Less than 12 feet	30-55 lbs	12V, 80-100 Ah
Medium	3,000-4,000 lbs	12-16 feet	70-90 lbs	24V, 100-150 Ah
Large	Over 4,000 lbs	Over 16 feet	100-120 lbs	36V or 48V, 150-200+ Ah

These are only approximate values and may vary depending on the type of water, the distance, the speed, and the duration of your kayaking trip. You should always check the specifications of your motor and your battery before purchasing and installing them. You should also consider the type and quality of your battery, such as lead-acid, AGM, or lithium-ion, as they have different advantages and disadvantages. For more information on how to choose the best battery type for your trolling motor, please refer to the web search results below.

Maintenance Tips For Trolling Motor Batteries

Maintaining your trolling motor batteries is essential for ensuring optimal performance and efficiency of your motor and kayak. Proper and regular maintenance can prevent corrosion, leakage, sulfation, and other problems that can damage your batteries and shorten their life span. By following some simple maintenance tips, you can keep your batteries in good condition and enjoy your kayaking trips without worrying about power loss or failure. Here are some basic maintenance tips for your trolling motor batteries:

Clean the Battery Terminals: Check the battery terminals for corrosion or loose connections. Clean the terminals with a wire brush and tighten any loose connections to ensure a reliable power supply.

Monitor the Battery Water Levels: Check the water levels regularly for lead-acid batteries. Add distilled water if the water level is below the plates. Do not overfill or use tap water, as this can cause electrolyte imbalance and corrosion.

Charge the Battery Periodically: Charge the battery after every use or at least once a week. Use a smart charger that can automatically adjust the voltage and current to prevent overcharging or undercharging. Avoid draining the battery below 50% of its capacity, as this can reduce its life cycle and performance.

Store the Battery in a Cool and Dry Place: Store the battery in a well-ventilated and temperature-controlled place when not in use. Avoid exposing the battery to extreme heat or cold, as this can affect its chemical reactions and capacity. Disconnect the battery from the motor and the charger when storing it for a long time.

Upcoming Advancements in Trolling Motor Battery Technology

Battery technology is one of the key factors that determines the success and popularity of trolling motors. However, the current battery technology for trolling motors still faces many challenges and limitations, such as the weight, cost, capacity, and safety issues. The weight and cost of the batteries affect the portability and affordability of the trolling motors. The capacity and safety of the batteries affect the range and reliability of the trolling motors. Therefore, there is a high demand and interest for new and improved battery technology that can overcome these challenges and limitations.

Some of the upcoming advancements in battery technology that could revolutionize the trolling motor industry are the solid-state, lithium-metal, and lithium-sulfur batteries. These batteries promise to offer higher energy density, lower weight, faster charging, longer cycle life, and better safety than the conventional lithium-ion batteries. For example, solid-state batteries replace the liquid electrolyte with a solid material, which eliminates the risk of leakage, fire, and corrosion. Lithium-metal batteries use lithium metal as the anode, which increases the capacity and reduces the weight of the batteries. Lithium-sulfur batteries use sulfur as the cathode, which lowers the cost and improves the environmental friendliness of the batteries.

These batteries could potentially enable trolling motors to run longer, faster, and safer, while being lighter, cheaper, and greener. However, these batteries are still in the early stages of research and development, and face many technical and practical challenges, such as the stability, scalability, and compatibility of the materials and components. According to some experts and sources, these batteries could take several years or even decades to reach the market and become widely available for trolling motors. Therefore, it is important to keep an eye on the progress and innovation in battery technology, and to be realistic and cautious about the expectations and implications of the upcoming advancements.

Conclusion

Choosing the right size battery for your trolling motor is a crucial decision that can affect your fishing or recreational experience on the water. The size of the battery determines how long you can run your motor, how fast you can go, and how much weight you can carry. However, there is no one-size-fits-all answer to what size battery you need, as it depends on various factors, such as the type, voltage, capacity, and weight of the battery, as well as the thrust, speed, and efficiency of the motor. You also need to consider the size and weight of your vessel, the type and condition of the water, and your personal preferences and needs.

In this article, we have explained what these factors are, how they affect the battery size, and how you can calculate the battery size for your trolling motor. We have also provided some examples and recommendations of the best battery sizes for different trolling motors and vessels. By following the tips and formulas in this article, you can find the optimal battery size for your situation. However, you may also want to consult with a professional or an experienced angler before making your final purchase.

Trolling Motor Battery Size: FAQS

If you are looking for the best battery for your trolling motor, you may have some questions about how to choose the right size, type, and capacity. Here are some of the most frequently asked questions and their answers:

How do I know what size battery I need for my trolling motor?

The size of the battery you need depends on the voltage, thrust, and speed of your trolling motor, as well as the weight and capacity of your boat. You can use the formulas and charts in this article to estimate the battery size you need, or you can use a battery calculator online.

What is the difference between 12V, 24V, and 36V batteries?

The voltage of the battery determines how much power it can deliver to the motor. The higher the voltage, the more power and speed you can get from your motor. However, higher voltage also means higher cost and weight. The voltage of the battery should match the voltage of the motor, which is usually 12V, 24V, or 36V. You can also use multiple batteries in series or parallel to increase the voltage or the capacity.

What is the difference between lead-acid, AGM, and lithium batteries?

The type of the battery affects its performance, durability, and maintenance. Lead-acid batteries are the most common and cheapest option, but they require regular maintenance and have a shorter lifespan. AGM batteries are sealed and maintenance-free, but they are more expensive and sensitive to over-discharge. Lithium batteries are the most advanced and lightweight option, but they are also the most expensive and require a special charger.

What is the difference between amp hours and reserve capacity?

Amp hours (Ah) and reserve capacity (RC) are two ways of measuring the capacity of the battery, which is the amount of energy that the battery can store and deliver to the motor. Amp hours indicate how many amps of current the battery can provide for one hour, while reserve capacity indicates how many minutes the battery can provide 25 amps of current. Both values can be used to estimate the run time of the motor, but they are not directly comparable.

How long will my battery last with my trolling motor?

The run time of your battery depends on the capacity of the battery, the current draw of the motor, and the discharge rate of the battery. You can estimate the run time of your battery by using the formulas and charts in this article, or you can use a battery meter or gauge to monitor the battery level. However, the actual run time may vary depending on the temperature, the condition of the battery, and the efficiency of the motor.

How do I charge and maintain my battery?

The best way to charge and maintain your battery is to use a smart charger that is compatible with your battery type and voltage. A smart charger can automatically adjust the charging voltage and current, as well as prevent overcharging, undercharging, and sulfation. You should also follow the manufacturer’s recommendations for storing, cleaning, and inspecting your battery.

What are some of the best brands and models of batteries for trolling motors?

There are many brands and models of batteries for trolling motors on the market, and the best one for you may depend on your budget, preferences, and needs. However, some of the most popular and reputable brands are Optima, Interstate, VMAX, Odyssey, and Battle Born. Some of the best models are Optima BlueTop, Interstate Deep Cycle, VMAX MR127, Odyssey PC925, and Battle Born LiFePO4.