Selecting the Best Trolling Motor Battery [Type & Size]

Having a reliable trolling motor battery is crucial for anglers who want all-day fishing trips without getting stranded on the water. With so many options like flooded, AGM, gel, and lithium batteries, choosing the best trolling motor battery can be tough. This guide covers everything you need to know - comparing battery types, runtimes, recharge rates, weight, and budgets to help you make the ideal choice. Whether you need a freshwater trolling motor battery for smaller lakes or extended range for saltwater and offshore use, we'll highlight the top batteries delivering ample power and steady performance. Invest in the right trolling motor battery to maximize your time on the water with smooth, quiet operation every cast of the way.

Table of contents

• Types of Marine Batteries for Trolling Motor 
• How I Chose the Best Trolling Motor Batteries
• Best Battery for Trolling Motor
• Conclusion
• FAQs

Types of Marine Batteries for Trolling Motor

When selecting a battery to power your trolling motor, you have several options - each with its own set of pros and cons. The ideal choice depends on factors like runtime needs, maintenance requirements, weight considerations, and budget. Here are the main types of marine batteries suitable for trolling motor applications:

Flooded Lead-Acid Trolling Motor Batteries

These are the most common types of batteries used by many because they either came with the boat or they are the most affordable type of battery. They usually cost less than $100.

Flooded Lead-Acid batteries, also called Wet-Cell batteries, typically last from 1-3 years, depending on how they are used and cared for. You will find that while Wet-Cell Lead-Acid batteries are the cheapest on this list, they are also the most demanding when it comes to the need for maintenance and safety:

• You need to regularly top-up Lead-Acid batteries with distilled water so that the battery's cells are always fully submerged. Failure to maintain a proper maintenance routine will damage your battery and drastically reduce its lifespan.
• You always need to make sure the battery's caps are tightly secured so that none of the battery's acid will overflow or spill into your boat. If the battery's acid somehow finds its way out of the battery, you might suffer damages due to corrosion of the boat and other property.

AGM (Absorbed Glass Mat) Trolling Motor Batteries

AGM batteries, AKA absorbed glass mat batteries, go by many names. You can sometimes find them referred to as Sealed Lead- Acid (SLA) batteries or Valve Regulated Lead Acid (VRLA) batteries.

What is an AGM battery? AGM batteries are an improvement on Flooded Lead-Acid batteries. But when compared to Flooded Lead-Acid batteries, AGM batteries have many areas where they are superior and preferable to Flooded or Wet-Cell Lead-Acid batteries.

AGM batteries vs. Flooded Lead-Acid batteries:

• AGM batteries are sealed so you don’t spend any time on maintenance and distilled water top-ups.
• They also have a longer lifespan of up to 4 years. Twice as long as traditional lead-acid batteries.
• They are lighter than their flooded (wet-cell) cousins.
• They do not overflow or give out any gas.
• AGM electrolytes in glass-fiber woven mat instead of liquid, so they are more suitable for marine use.

While AGM batteries are usually more expensive than flooded batteries, in our opinion, the increased cost is a worthwhile investment because AGM batteries offer better performance, double lifespan, increased safety, and more.

Gel Trolling Motor Batteries

A Gel Battery, also known as a Gelled Electrolyte Battery, is a rechargeable battery that uses a gelled electrolyte instead of the usual liquid electrolyte found in Wet-Cell batteries.

Gel batteries are another branch of Sealed Lead-Acid (SLA) or Valve Regulated Lead Acid (VRLA) batteries just like AGM batteries. So they share many of the same features and advantages. For example:

• Gel batteries are also sealed to prevent spillage leakage.
• They also use a gel electrolyte that’s suitable for use in unstable and turbulent environments.
• They are 100% maintenance free and don’t need any electrolyte top-ups.
• They don’t give out any gas.
• For more related information, please click Solar Gel Batteries: Everything You Need To Know.

Lithium Iron Phosphate Trolling Motor Batteries

The latest improvement in deep-cycle battery technology. Lithium Iron Phosphate batteries, also referred to as LiFePO4 batteries or lithium marine batteries, boast the longest battery lifespan of any marine or deep-cycle battery.

They are the best battery for a trolling motor any boatsman, yachtsman, or angler could want. The only drawback is that they are also the most expensive battery type. That being said, lithium batteries have many features desirable to people who venture into the deep, including:

• They are the smallest and lightest battery type suitable for use on both big and smaller vessels.
• They are sealed, so they don’t need any maintenance.
• They have extremely long lifespans of up to 10 years. 5 times longer than flooded batteries and 3 times longer than AGM batteries.  

And these are only part of the advantages they offer. LiFePO4 batteries offer several performance advantages such as a longer staying power without voltage drop, 100% depth of discharge, and faster charging times.

On the other hand, the biggest disadvantage of Lithium batteries is that they are expensive. The good news is that the cost continues to drop as more and more manufacturers and people adopt the technology.

How I Chose the Best Trolling Motor Batteries

Finding the perfect trolling motor battery for your fishing boat can be a daunting task, but with the right information, it doesn't have to be. Here are some guidelines to help you select a battery that can supply clean, safe power to your trolling motor.

Battery Capacity - Amp Hour Rating

• We recommend selecting a 12-volt deep cycle marine battery with at least a 100 amp hour (Ah) rating. Usually, a Group 27 size or larger is ideal.
• The higher the amp-hour rating, the longer your trolling motor will run on a single charge.
• If an amp-hour rating is not available, look for a deep cycle battery with a minimum of 180 minutes reserve capacity.

Battery Type and Group Size

• Choose a battery type and group size that fits your budget, performance requirements, and available space on your boat.
• Do not mix battery types (e.g., Lead-Acid and Lithium) in 24 or 36-volt systems. Always connect batteries of the same type in a series.

Deep Cycle vs. Cranking/Starting Batteries

• Regardless of the battery type you choose, ensure it's a "deep cycle" battery designed for continuous power delivery.
• When shopping for Lithium marine batteries, you may not see the term "Deep Cycle," but essentially all LiFePO4 batteries are designed to operate this way.
• Cranking or starting batteries are not suitable for trolling motor use as they focus on providing a quick, strong burst of power to start your outboard engine, rather than long-lasting power for trolling.

Other Considerations

• Select a battery that can withstand the turbulence and challenges of being out on the water.
• For confined spaces, choose a sealed, maintenance-free battery with no risk of spills, refills, or gas releases.
• Consider the weight of the battery, ensuring it's light enough for your target vessel.

By following these guidelines, you can ensure that your trolling motor battery has sufficient capacity to power your motor for the desired duration, while also being safe, durable, and easy to use on your fishing boat.

Best Battery for Trolling Motor

When it comes to finding the best battery for your trolling motor, Lithium Iron Phosphate (LiFePO4) batteries stand out as the superior choice. Despite their higher upfront cost, LiFePO4 batteries offer numerous advantages that make them an excellent investment for any boater.

First and foremost, LiFePO4 batteries boast an impressive lifespan of up to 10 years, significantly outlasting traditional lead-acid batteries. This longevity translates into long-term cost savings and reduced maintenance hassles.

Moreover, LiFePO4 batteries are remarkably lightweight and compact, making them easier to handle and install, especially in space-constrained vessels. Additionally, these batteries are maintenance-free, eliminating the need for electrolyte top-ups or other tedious upkeep tasks.

One of the most remarkable features of LiFePO4 batteries is their ability to deliver consistent, high-powered performance until the very last drop of energy. Unlike lead-acid batteries, which experience a gradual decline in output as they discharge, LiFePO4 batteries maintain their voltage and current output until they are nearly depleted, ensuring reliable and efficient operation of your trolling motor.

Recognizing the exceptional performance and convenience of LiFePO4 batteries, we highly recommend investing in a high-quality Lithium Iron Phosphate battery for your trolling motor needs. Our line of Renogy LiFePO4 batteries is designed to meet the demanding requirements of marine applications, offering superior power delivery, extended lifespan, and hassle-free operation.

If LiFePO4 batteries are currently outside of your budget, we also offer reliable Absorbed Glass Mat (AGM) and Gel batteries with a lifespan of up to 4 years. While not as long-lasting as LiFePO4 batteries, these options provide a cost-effective alternative for those seeking quality deep-cycle batteries.

At Renogy, we are committed to providing our customers with a wide range of high-performance battery solutions, as well as other essential marine products such as solar panels, pure sine wave inverters, and more. Feel free to explore our online store or contact us directly to learn more about our offerings and find the perfect power solution for your boating needs.

Conclusion

Most anglers only think about their trolling motor batteries when they weaken or die, but that’s a mistake. Reliable batteries are essential, especially for kayak anglers and those fishing in currents, where long-lasting power is critical. Bigger boats also benefit from robust batteries, as high gas prices make it more efficient to thoroughly fish one area rather than move around. The best trolling motors need the best batteries to reach their full potential.

For optimal performance, we recommend Renogy LiFePO4 batteries. For budget-friendly options, Renogy's AGM and Gel batteries deliver reliable performance. Invest in the right battery to ensure smooth, quiet operation and maximize your time on the water. Explore Renogy's high-performance marine batteries today.

FAQs

What is the longest lasting battery for a trolling motor?

The longest-lasting battery for a trolling motor is a Lithium Iron Phosphate (LiFePO4) battery. These batteries can last up to 10 years, providing consistent power without voltage drop, a 100% depth of discharge, and faster charging times. Though more expensive upfront, their extended lifespan and superior performance make them a worthwhile investment. Renogy's LiFePO4 batteries are an excellent choice, offering reliable, maintenance-free power for trolling motors, ensuring extended fishing trips without worry.

What size battery do I need for a 55 lb thrust trolling motor?

A Newport Vessels (NV) 55 lb thrust trolling motor draws 52A at full speed. A 100Ah battery can run it at full speed for nearly 2 hours, while a 50Ah battery lasts almost an hour. However, trolling motors are rarely used continuously at top speed. Properly managed, a 100Ah battery can power the motor all day. Some anglers report using a 50Ah battery for a full day. For peace of mind, we recommend a battery with a higher Ah rating than the motor's maximum draw, like Renogy's 100Ah deep-cycle batteries (lithium, AGM, Gel).

How long will a 100Ah lithium battery last on trolling motor?

To determine how long a battery will last on your trolling motor, use this formula:

Running Time = Battery Ah Capacity / Trolling Motor Current Draw

For example, if a trolling motor draws 54A at full speed, a 100Ah lithium battery will last:

Running Time = 100Ah / 54A = 1.85 hours or 1 hour 51 minutes

To find the running time at different speeds, adjust for the motor's current draw. For instance, if the same motor draws 10A at half speed, the 100Ah battery will last:

Running Time = 100Ah / 10A = 10 hours

This formula helps calculate the duration any battery will last with your trolling motor by substituting the battery's Ah rating and the motor's current draw.