What Size Marine Battery Do I Need for Trolling Motor

Published on: July 7, 2023
Written by Liam Jaxon / Fact-checked by David Rowan

The size of the marine battery for your trolling motor largely depends on the thrust of the motor. For a 55 lb thrust trolling motor, a deep cycle marine battery of at least 100 Amp hours (Ah) is recommended, while a 30 lb thrust motor would work well with a 50-60 Ah battery.

Marine batteries are pivotal components for smooth trolling motor operations. The thrust level of the motor can help define the battery size required. Take, for instance, the 55 lb thrust trolling motor. This particular type of motor necessitates a potent battery, typically deep cycle marine batteries with a minimum of 100 Amp hours (Ah). On the other hand, a 30 lb thrust motor operates efficiently with a battery providing 50-60 Ah. Both scenarios emphasize the correlation between motor thrust and battery size.

what size marine battery do i need for trolling motor

The conversation around trolling motor batteries would be incomplete without mentioning the best options for an 80 lb thrust motor. Given its higher power demand, such a motor works optimally with a deep cycle marine battery boasting at least 150 Ah. This recommendation ensures adequate power provision even during extended use.

In terms of voltage, the most common choice is a 12v trolling motor battery. Its popularity stems from the balance it offers between power provision and physical size, making it ideal for most trolling motors.

There’s an array of options for those looking for the best trolling motor battery on a budget. Lead-acid batteries, for example, offer a good balance of performance and cost, even though they may not have the longevity or lightness of more expensive options.

Lithium trolling motor batteries, despite being pricier, offer exceptional longevity, weight advantages, and quicker recharge times. Their benefits often justify the cost, particularly for frequent users or those running high-thrust motors. Overall, the right battery size for your trolling motor largely depends on the motor’s thrust, the duration of use, and, of course, your budget.

Selecting the Right Voltage and Amp Hour Rating

The heart of powering your trolling motor lies in choosing the correct voltage. A 12-volt deep cycle marine battery is a typical choice for many boaters due to its balance between power output and size. The choice of a deep cycle battery is pivotal because of its capacity to provide power over a long duration and its ability to be recharged many times.

Next, consideration of the amp-hour rating becomes vital. An amp-hour (Ah) refers to the amount of charge a battery can deliver for one hour. A battery with a 110 Ah rating, for example, can theoretically deliver a 1-amp current for 110 hours or a 10-amp current for 11 hours. This means the higher the Ah rating, the longer the run time of your trolling motor.

Importance of Battery Size: Group 27 or Larger

Battery size matters as well, and not just in physical dimensions. The ‘group size’ of a battery refers to its power capacity and physical size. Group 27 batteries, and larger, are recommended for trolling motors due to their larger capacity. These sizes allow for an increased Ah rating, which translates into more time out on the water.

what size marine battery do i need for trolling motor

Maximizing Run Time

The primary goal is to optimize your trolling motor’s run time. This is where the higher amp-hour rating comes into play. Simply put, the higher the Ah rating, the more power your battery can deliver over time, meaning your trolling motor can run longer.

Battery Life and Maintenance

Choosing the right battery is one aspect, maintaining it for extended life is another. Deep cycle marine batteries are designed to be discharged and recharged many times, making them perfect for trolling motors. Proper maintenance, such as regular charging and preventing full discharges, can help extend the battery’s life.

Considerations for High-Thrust Trolling Motors

For higher-thrust trolling motors, such as those rated at 80 lb thrust or more, it’s wise to opt for batteries with even higher Ah ratings, or consider using multiple batteries. This provides the extra power needed for these high-demand motors, ensuring that they run efficiently during your boating adventures.

In all these considerations, remember that every trolling motor setup is unique. The right battery for your needs will depend on your specific motor, how long you’re out on the water, and the conditions you’re operating under. Always make sure to match the battery to your specific situation to get the best performance.

what size marine battery do i need for trolling motor

Marine Battery Size Chart for Trolling Motor 

The most common marine battery sizes are 22NF, 24M, 25, 27M, 31M, 34M, 35, and 65 which are acceptable for different kinds of trolling motors. We include here a chart of several boat batteries size and minimum thrust levels and more. 

Battery Size Battery TypesBoat’s Weight Thrust Level 
12-volt battery Deep Cycle 150030lb
12-volt battery Deep Cycle 200040 to 45lb 
12-volt batteryDeep Cycle 250050 to 55lb
24-volt batteryDeep Cycle 3000 – 350070lb
24-volt batteryDeep Cycle 400080lb
36-volt batteryDeep Cycle 4000+101 to 112lb 

If the 12V and 24V battery batteries have a 100 to 120 Ah amp hours rate, they allow you to run for more than three hours. In this case, a higher amp hour rate is good for enjoying more run time of the trolling motor. Don’t forget to charge a deep discharge marine battery timely. Check this article on how to do it.

Frequently Asked Questions (FAQs)

What Is the Ideal Battery for a 55lb Trolling Motor?

A 55lb trolling motor generally requires a deep-cycle marine battery with a capacity of at least 100 Ah. This should provide enough power for extended use.

What Size Trolling Motor Battery Should I Look for Based on My Trolling Motor’s Needs?

When choosing a trolling motor battery, consider the needs of your trolling motor. Look for battery features and considerations such as the voltage, amp-hour rating, and battery type. Match the battery size to the motor’s power requirements to ensure optimal performance on the water.

How Many AGMs Are Required to Power a Trolling Motor Efficiently?

Choosing the right agms for trolling motor is crucial for optimal performance. The number of AGMs required depends on factors like motor size, desired speed, and battery capacity. Assessing these factors will help determine the ideal number needed to power the trolling motor efficiently.

How to Choose the Right Marine Battery for a Trolling Motor?

When selecting a marine battery for a trolling motor, maximizing marine battery performance is essential. Consider factors such as battery type, capacity, and maintenance requirements. Opt for a deep cycle battery specifically designed for marine applications. Check its capacity to ensure sufficient power for your trolling motor. Regularly caring for and charging the battery properly will also help prolong its performance.

What Is the Best Size Battery for a Trolling Motor?

The best size battery for a trolling motor largely depends on the motor’s thrust. As a rule of thumb, a 12-volt deep-cycle marine battery with an amp-hour rating that matches the power consumption of the motor is recommended.

Are There Specific Batteries for 12v Trolling Motors?

Yes, the most commonly used batteries for 12v trolling motors are 12v deep-cycle marine batteries. They can consistently deliver power over extended periods and withstand regular charging and discharging.

Can You Recommend a Good Lead Acid Trolling Motor Battery?

The Universal UB121000-45978 12v 100AH Deep Cycle AGM Battery is a highly recommended lead-acid battery due to its long-lasting power and reliable performance.

Why Would One Consider a LiFePO4 Battery for a Trolling Motor?

LiFePO4 (Lithium Iron Phosphate) batteries are lighter, have a longer lifespan, and can provide stable power for a longer period. They are more expensive upfront, but their durability can make them more cost-effective over time.

Is There a Best Affordable Trolling Motor Battery?

Yes, lead-acid batteries are often cited as the best affordable option for trolling motors. They provide a balance between performance and cost, although they may not last as long as more expensive alternatives.

What’s the Best Trolling Motor Battery?

The best battery can vary based on specific needs, but some popular options include the Optima Batteries 8016-103 D34M BlueTop and the Universal Power Group 12V 100Ah Battery. Both offer long-lasting power, are reliable, and have received positive user feedback.


The size of the marine battery you need for a trolling motor will depend on several factors, including the power of the trolling motor, the length of time you plan to use it, and the number of times you plan to use it in a day. A general rule of thumb is to use a battery with at least 50 amp-hours of capacity for a trolling motor of 50-70 pounds of thrust and a 12-volt system. It’s also important to consider the type of battery you need, such as a deep cycle battery or a starting battery. It’s always recommended to check the manual of your trolling motor or consult with a professional for the exact battery requirement for your specific setup.

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About This Writer

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Hi, I am responsible for the 'Homeowners Power Solutions' category. My name is Liam Jaxon and a licensed technician with 7 years of experience in vehicle batteries, electrical gadgets, and home appliances. My working experience in different residential & light commercial electrical sectors and the automobile industry helped to acquire vast knowledge in this industry.

Hi, I am responsible for the 'Homeowners Power Solutions' category. My name is Liam Jaxon and a licensed technician with 7 years of experience in vehicle batteries, electrical gadgets, and home appliances. My working experience in different residential & light commercial electrical sectors and the automobile industry helped to acquire vast knowledge in this industry.