What Do Volts Mean in Electric Trolling Motors: Understanding the Basics

In electric trolling motors, volts represent “electrical pressure” that pushes the flow of electrons through the motor’s circuitry. Higher voltage typically results in more thrust.

Choosing the correct voltage for your trolling motor depends on thrust and boat weight considerations. Trolling motors are found in these voltage denominations: 12 Volt, 12/24 Volt, 24 Volt, and 36 Volt.

Before we get into the meat of the article, here’s a quick snapshot of the key takeaways:

At a Glance:

1️⃣ Volts represent “electrical pressure”, amps = current, and watts are indicative of work rate.

2️⃣ The power output or thrust of a trolling motor is directly linked to its voltage rating – more thrust is better suited for heavier boats.

3️⃣ The weight of the boat directly influences the choice of voltage and thrust level for your trolling motor; generally, a fully-loaded boat needs at least 2 lbs of thrust for every 100 lbs of weight.

🤝 Relationship Between Volts, Amps & Watts

Let’s refresh our memories back to middle school with the formula: Volts X Amps = Watts

You can’t talk about Volts without talking about Watts and vice versa. Here’s an analogy to break it down.

Imagine voltage as water pressure in a garden hose. The higher the pressure, the more water is forced through the hose and the further it can squirt out.

Similarly, voltage is like the “electrical pressure” that pushes electrons through a wire. The higher the voltage, the more electrical energy is being moved through the wire.

Watts can be thought of as the speed at which work is done. So if you and a friend are filling buckets with water from two hoses with the same pressure but different diameters, your wider hose allows more water flow (current).

High wattage comes from increased let’s flow, letting you fill the bucket faster. Similarly, a device with higher wattage draws more current at the same voltage, using energy more quickly.

Once you understand the relationship between Volts, Amps (current), and Watts, then you’re already halfway there. Now let’s look at the other half of the question.

Voltage vs Power

The power output of a trolling motor is directly related to the chosen voltage rating. Higher voltages correspond to increased power. Therefore, thrust is an important performance metric for trolling motors.

It refers to the pushing or pulling force exerted by the motor on the boat, measured in pounds of thrust. Generally, a greater amount of power is needed to achieve higher thrust levels.

Therefore, trolling motors with higher voltage ratings can produce more thrust, enabling them to propel larger or heavier boats more effectively. This is important to consider when deciding what size electric trolling motor you need.

36V~100 lb
24V~80 lb
12V~55 lb

🚀 Relationship between Thrust and Boat Weight

Thrust is a crucial factor in electric trolling motors as it determines the power and efficiency of the motor in propelling the boat.

When talking about trolling motors, many people use the terms thrust and horsepower interchangeably. Take a look at our article, thrust to horsepower, to better understand the differences between the two.

When it comes to boat weight, there is a direct relationship between the two. A heavier boat requires more thrust to move effectively, while a lighter boat can function efficiently with a lower amount of thrust.

A general rule of thumb is to have a minimum of 2 lbs of thrust for every 100 lbs of boat weight, fully loaded. This means that if your boat weighs 3,000 lbs, fully loaded, the calculation would be (3,000/100) * 2 = 60 lbs of thrust required for adequate performance.

☑️ Choosing Motor Thrust for Different Boats

When selecting a trolling motor for your boat, it is essential to consider its weight and size. Here are some brief guidelines for common boat types:

  • Canoe or Kayak: Small and lightweight boats like canoes and kayaks can often function well with a 12V trolling motor that provides around 30-55 lbs of thrust.
  • Bass Boat: A 24V trolling motor with 70-80 lbs of thrust is recommended for a typical bass boat to deliver adequate performance.
  • Larger Boats: Heavier boats may require a 36V trolling motor with 100+ lbs of thrust to move effectively.

Take note that these are general guidelines, and factors such as personal preferences, fishing conditions, and boat designs can impact the thrust requirements.

It is always recommended to consult with experts or try out different trolling motors before making a final decision. For a more in-depth look at thrust, take a look at our trolling motor thrust guide.

Battery Runtime and Efficiency

This section looks at voltage and current in relation to trolling motor batteries.

Impact of Voltage on Runtime

The increased power of higher voltage systems may lead to shorter runtime due to higher energy consumption, while lower voltage systems prioritize longer runtime with less power.

Amp Draw and Amperage

If you recall our formula from the beginning of the article, you’ll remember the third part, namely Amps.

Amp draw is like how much electricity a trolling motor takes from the battery when it’s running, and it’s measured in something called amps.

This affects how long your motor can run because batteries have a limit on how much electricity they can give before they run out. This limit is called the amp-hour rating (Ah).

To calculate the runtime of a trolling motor, you can use the formula: AH Battery Rating / Amp Draw = Runtime. For example, if a motor has an amp draw of 20 amps at medium speed and uses a 100 amp-hour rated battery, the estimated runtime would be 100 Ah / 20A = 5 hours of run time.

Factors Affecting Battery Runtime

Several factors can affect the runtime and efficiency of trolling motor batteries, including:

  • Motor type and size: Larger motors typically have higher amp draw, which can reduce battery runtime.
  • Motor speed: Higher-speed settings increase amp draw, leading to shorter battery runtime, whereas slower speeds can conserve battery life.
  • Water and weather conditions: Strong currents, wind, and swell can increase the amp draw of your trolling motor as it works harder to maintain position.
  • Battery maintenance: Proper battery maintenance, such as regular charging and storage, can help maintain optimal performance and extend battery life.

🧭 Navigating Manufacturers and Models

Electric trolling motors come in 12, 24, or 36 volts. Each voltage category is designed to cater to different boat sizes and performance requirements.

A 12-volt trolling motor is ideal for smaller boats, while a 36-volt system is best for larger boats requiring more power.

Two well-established manufacturers in the industry are Minn Kota and MotorGuide, both offering a wide range of electric trolling motors that differ in voltage levels, thrust, and additional features. Here are some points to consider when navigating through the manufacturers and models:

Manufacturer ReputationCompare reliability, quality, and customer support of different brands.
VoltageHigher voltage means shorter battery life; balance performance, and runtime.
ThrustHigher thrust levels offer better movement and control for heavier boats or tough conditions.
Battery lifeHigher voltage means shorter battery life; balance performance and runtime.
Additional featuresConsider options like GPS positioning or wireless control for an improved fishing experience.

💯 Selecting the Right Setup

Choosing the proper setup for your boat hinges on understanding the significance of voltage and its connection to battery quantity.

A 12-volt trolling motor runs off a single 12-volt deep cycle battery. For a motor with more than 55 lbs of thrust, up to 80 lbs of thrust, you will need two 12-volt batteries, providing a total of 24 volts. 

A 36-volt trolling motor requires three 12-volt batteries to operate correctly. Understanding the voltage and battery requirements will ensure optimal performance for your trolling motor and minimize potential issues such as sulfation.

🔑 Key Takeaways

In conclusion, the three most important points to remember are:

1️⃣ Voltage in electric trolling motors influences power and efficiency, with higher voltage providing more thrust and lower voltage prioritizing longer runtime.

2️⃣ Thrust is crucial for effective boat propulsion, and selecting the right trolling motor requires considering boat weight and size.

3️⃣ Battery life and runtime are affected by voltage, amp draw, motor speed, and other factors; balancing performance and runtime is key when choosing a trolling motor.

For a comprehensive rundown of battery types, check out this article, batteries for electric trolling motors.

Nice to e-meet you. I’m Justin, a seasoned sailing journalist and communications pro with more than 25 years of extensive industry experience. And a track record of successfully promoting teams and events on the global stage.