When it comes to trolling motors, having the right battery is essential to ensure you get the best performance when on the water. With so many different types of batteries available on the market, choosing the right one can be a confusing and overwhelming process, even for experienced boaters.
That’s where this expert guide comes in. Whether you’re a seasoned angler or a first-time boat owner, this guide will provide you with all the information you need to select the right trolling motor battery for your needs.
What Size Trolling Motor Do I Need?
The size of the trolling motor you need will depend on a variety of factors, including the size and weight of your boat, the water conditions you’ll be navigating, and the level of control and speed you require.
You want the motor to have enough thrust to propel your boat through the water at a steady pace without straining the motor or draining the battery too quickly. A good rule of thumb is to aim for 2 pounds of thrust per 100 pounds of weight on your boat, although this can vary depending on factors such as wind and current.
It’s also important to consider the length of the motor shaft, which should be long enough to keep the propeller fully submerged in the water at all times, even in rough or choppy conditions, to provide the best efficiency and longer life span from your battery selection.
For most anglers, selecting the right size trolling motor for your boat will take a bit of time and some research since the best option will depend on your specific needs, preferences, and boat type.
What Type of Trolling Motor: Lithium vs AGM vs Lead Acid Wet Cell
Lithium marine batteries are a relatively new technology that is rapidly gaining popularity in the trolling motor industry due to their high energy density, lightweight, and long lifespan. Compared to traditional lead acid deep cycle batteries, lithium batteries can store up to three times as much energy per unit weight, meaning these batteries can provide more power and run longer on a single charge.
Lithium marine batteries also have a much longer lifespan than a flooded lead acid battery, with some models lasting up to 10 years or more, and they are virtually maintenance-free. Lithium batteries can be charged much more quickly than traditional deep-cycle batteries, and these batteries can be charged and discharged more times without reducing their overall lifespan.
While lithium marine batteries are generally more expensive than other types of batteries, their performance and durability make these batteries a worthwhile investment for serious anglers and boaters who demand reliable, high-performance equipment.
Absorbent Glass Mat batteries are a type of deep-cycle flooded lead-acid battery for a trolling motor that uses a specialized fiberglass mat to absorb and hold the battery acid. This design helps prevent spills and leaks, making AGM batteries a popular choice for boaters who need a reliable, maintenance-free power source, especially on choppy water or offshore waves.
AGM batteries are also known for their high energy density, which means they can store more energy in their reserve capacity than traditional deep-cycle lead-acid batteries. This allows AGM batteries to deliver more power per amperage hour rating and run longer on a single charge, which is exactly what you want for many trolling motors.
These deep-cycle batteries can be charged more quickly than a traditional deep-cycle battery, and they can be discharged more deeply without damaging the battery or reducing its overall lifespan.
Lead Acid Wet Cell Batteries
Lead Acid Wet Cell batteries are the oldest and most commonly used type of battery for trolling motors. They are relatively inexpensive, widely available, and have a long history of reliable performance in a wide range of applications.
These batteries use a liquid electrolyte solution and lead plates to store and deliver electrical energy. While they are heavier and less energy-dense than lithium or AGM batteries, they are still a popular choice for boaters who need a reliable and affordable power source for their trolling motor.
Trolling Motor Sizing for Different Boat Lengths and Weights
Choosing the right size motor for your boat depends on its length and weight. Generally, the larger and heavier the boat, the more thrust you will need from your trolling motor to achieve optimal performance on the water.
As a general rule of thumb, aim for 2 pounds of thrust per 100 pounds of boat weight regardless of the motor or battery type. For example, a 17-foot boat weighing around 1,700 pounds would require a motor with at least 34 pounds of thrust and a battery type strong enough to run it.
It’s also important to consider other factors as well such as wind and current conditions, water depth, and the type of water you’ll be navigating. Boats that will be used in windy or rough water will require a more powerful trolling motor to maintain control, while boats used in calm water conditions can get away with a smaller motor.
Motor Wiring Overview
Trolling motor wiring can seem overwhelming for any battery-type installation, but it’s actually quite straightforward. Here is a basic overview of trolling motor wiring:
Determine the Battery Voltage
The first step in wiring your trolling motor is to determine the voltage of your battery. Most trolling motors operate on 12-volt or 24-volt systems, although some may require higher voltage. Make sure the voltage of your battery matches the voltage requirements of your trolling motor.
Connect the Positive and Negative Leads
Once you know the voltage of your battery, connect the positive and negative leads of your trolling motor to the corresponding terminals on your battery. Make sure to connect the positive lead to the positive terminal and the negative lead to the negative terminal.
Use the Correct Wire Gauge
It’s important to use the correct wire gauge when wiring your trolling motor. The wire gauge should be based on the amperage of your motor, as well as the length of the wire run. You should be able to find a wire gauge chart to determine the correct wire gauge needed.
Use a Circuit Breaker or Fuse
To protect your trolling motor from electrical overload, it’s important to use a circuit breaker or fuse. These should be rated for the amps of your trolling motor and should be installed in line with the positive lead.
Use a Wiring Harness
A wiring harness is a pre-made set of wires with connectors that are designed to fit specific trolling motor models. Using a wiring harness can eliminate the need to crimp connectors or solder wires, making the wiring process faster and more reliable.
Check Your Connections
Once you have wired your trolling motor, it’s important to check your connections to ensure they are secure and tight. Use a multimeter to test the voltage of your battery and ensure it is delivering the correct voltage to your trolling motor.
Trolling Motor Plugs & Receptacles
Trolling motor plugs and receptacles are essential components of the wiring system and are necessary for all battery types. They are used to connect the trolling motor to the battery and allow for easy installation and removal of the motor itself.
There are two types of trolling motor plugs and receptacles: two-wire and three-wire. Two-wire plugs and receptacles are used for 12-volt systems and have a positive and a negative wire. Three-wire plugs and receptacles are used for 24-volt or 36-volt systems and have two positive and one negative wire.
While there can be a variety of styles and configurations of plugs and receptacles across different battery types, most have a male plug and a female receptacle that fit together to create a secure connection. They are made of durable materials like plastic or metal and are designed to be resistant to corrosion, moisture, and other environmental factors.
When selecting a trolling motor plug and receptacle, it’s important to choose one that is compatible with your trolling motor and battery. Look for plugs and receptacles that are rated for the amps of your trolling motor and match the voltage of your battery.
How Long Does a Trolling Motor Battery Last?
The lifespan of a trolling motor battery can vary depending on several factors, including the type of battery, the frequency and duration of use, and the conditions in which the battery is used and stored.
A lead-acid wet cell battery typically lasts between 2 and 4 years with proper maintenance. AGM and lithium batteries may last longer, with some lithium batteries boasting a lifespan of up to 10 years or more.
The frequency and duration of use can absolutely affect the lifespan of a trolling motor battery. Batteries that are used frequently or for long periods of time will often wear out sooner than batteries that are used less often or for shorter periods of time.
Batteries that are exposed to extreme temperatures, high humidity, or other harsh conditions may have a shorter lifespan than batteries that are used and stored in more moderate conditions. Proper maintenance, such as regular charging and cleaning, can help extend the lifespan of a battery.
Best 12v 100ah Lithium Battery for Trolling Motor
My personal favorite is the Battle Born brand of batteries. These are high-quality lithium iron phosphate deep-cycle battery that is compatible with most 12V motors. This brand has a long lifespan, is lightweight, and features a built-in battery management system for added safety and performance.
If you’re looking for a more robust brand, consider the ExpertPower brand lithium deep-cycle rechargeable battery. This brand is designed for high performance and reliability. It has a built-in battery management system for added safety and features a rugged, waterproof design that is suitable for use in harsh marine environments.
Trolling Motor FAQs
Can I Use a Dual Purpose Marine Battery for My Trolling Motor?
Yes, but it’s important to choose a dual-purpose battery that is appropriate for your trolling motor’s power requirements. Dual-purpose batteries are designed to provide both starting battery power and deep cycle power with good cold-cranking amps, which makes them a great choice for boats that have limited space and power needs.
What Trolling Motor Works With Lowrance?
The Lowrance Ghost trolling motor is specifically designed to work seamlessly with Lowrance electronics, including fish finders and chartplotters while providing a good electrical power output. It’s available in both 24V and 36V consistent power models with a range of thrust levels and features Lowrance’s anchor system so you can lock onto a fishing spot and hold your position with pinpoint accuracy.
In addition to the Ghost, Lowrance also works well with the MotorGuide Xi5 and Xi3 trolling motors using the Lowrance gateway kit. The Xi5 and Xi3 are available in both 12V and 24V models with a range of thrust levels to fit casual boaters, as well as offshore anglers needing a trolling motor to hold up to rough waves and strong currents.
What Trolling Motor Works With Humminbird
The Minn Kota Ulterra motor is my personal favorite extremely lightweight brand to use with Humminbird electronics. The Ulterra has a range of advanced features, including Auto Stow/Deploy, which allows you to easily raise and lower the motor with the push of a button.
In addition to the Ulterra, there are also the Terrova, PowerDrive, and Riptide models that all provide enough power to work well with Humminbird chartplotters and fish finders. One of the best features of these trolling motors is their wireless control and GPS navigation system.
What Trolling Motor Works With Garmin?
For Garmin electronics, consider the Garmin Force motor as a smart investment to make. It’s quiet, offers efficient performance, and is available in both 24V and 36V models with a range of thrust levels for large and small boats.
If you’re not in love with the Force trolling motor or have space limitations, the MotorGuide Xi5 and Xi3 trolling motors mentioned in the Lowrance section are also compatible with electronics using the Garmin NMEA 2000 Gateway.