What an Electric Trolling Motor Does

An electric trolling motor is a battery-powered propeller mounted on the bow or stern of a boat that lets you move slowly and quietly without starting the main engine. It runs on a rechargeable battery, typically 12, 24, or 36 volts depending on the motor size, and gives you precise control over speed and direction using a foot pedal or hand remote. Most anglers use them to position the boat over fish, hold position against wind or current, or move through shallow water where the main engine would run aground.

The motor sits in a housing that can be tilted up when you're not using it, and the propeller shaft extends down into the water. You steer by turning the entire motor head left or right, rather than using a rudder. Because there's no fuel, no exhaust, and no loud engine noise, the motor won't spook fish and won't disturb other boaters in quiet areas.

Key Takeaways

  • Electric trolling motors come in three voltage classes — 12V, 24V, and 36V — with higher voltage meaning more power and longer runtime on the same battery.
  • Thrust is measured in pounds and ranges from 30 to over 100 pounds; you need roughly 2 pounds of thrust per 100 pounds of boat weight to move at a useful speed.
  • Battery capacity and weight are the biggest factors in how long the motor will run; a single 12V battery lasts 2 to 4 hours at half throttle, while larger systems can run 8 hours or more.
  • Freshwater and saltwater motors are different — saltwater models have corrosion-resistant parts and cost more, so buying the wrong type will shorten the motor's life.
  • You'll need a battery charger rated for the voltage of your system, and charging time ranges from 4 to 12 hours depending on battery size and charger type.

Thrust, Voltage, and How to Choose the Right Size

The first decision is how much thrust you need. Thrust is measured in pounds and tells you how hard the motor pushes. A general rule is 2 pounds of thrust per 100 pounds of total boat weight — so a 2,000-pound boat needs roughly 40 pounds of thrust. A small 12-foot fishing boat might use 30 to 50 pounds; a 20-foot boat typically needs 55 to 80 pounds. If you're in a heavier boat or often fish in strong current, you'll want the higher end of that range.

Voltage determines how much power the motor can deliver and how long it runs between charges. A 12V motor is the lightest and cheapest, but it draws more current from the battery, so it runs for a shorter time. A 24V motor is more efficient — it draws less current for the same power — so it runs longer on a similar battery capacity. A 36V motor is the most efficient and runs longest, but the system costs more and weighs more because you need more batteries. Most small boats use 12V or 24V; 36V is common on larger boats or when anglers want to run the motor all day without recharging.

The motor's shaft length also matters. Shaft length is measured in inches and ranges from 30 to 72 inches. A longer shaft lets you mount the motor deeper in the water without it sticking out above the gunwale, which is important if your boat has high sides or if you want to tilt the motor up when you're running the main engine. Measure from the mounting surface to the waterline to find the right shaft length for your boat.

Battery Systems and Runtime

The battery is what powers the motor, and the type and size you choose determine how long you can fish before you need to recharge. A single 12V battery rated at 100 amp-hours (written as 100Ah) will run a 12V trolling motor for roughly 2 to 4 hours at half throttle, depending on the motor's thrust and how hard you're pushing it. Running at full throttle cuts that time in half. A 24V system uses two 12V batteries wired together, which doubles the runtime compared to a single 12V battery.

Lithium batteries last longer per charge than lead-acid batteries and weigh less, but they cost two to three times as much. Lead-acid batteries are cheaper and work fine for casual fishing, but they're heavier and need more maintenance — you have to check the water level in flooded-cell batteries and keep the terminals clean. Sealed lead-acid batteries (also called AGM or absorbed glass mat) don't need water added and are more resistant to vibration, so they're a good middle ground.

Battery capacity is measured in amp-hours. A larger amp-hour rating means longer runtime. If you plan to fish for 8 hours without recharging, you'll need either a very large single battery or multiple batteries wired together. Most anglers who fish a full day use a 24V or 36V system with multiple batteries, or they bring a second battery and swap it out at midday.

Freshwater Versus Saltwater Motors

Saltwater trolling motors have corrosion-resistant parts — the shaft, propeller, and internal components are made of stainless steel or coated to resist rust and salt damage. Freshwater motors use standard steel parts that will corrode quickly if exposed to salt. If you use a freshwater motor in saltwater, it will rust from the inside out within a season, and repairs will be expensive or impossible.

Saltwater motors cost 20 to 40 percent more than freshwater models of the same thrust and voltage. If you fish only in freshwater, buy a freshwater motor and save the money. If you fish in both, buy a saltwater motor — it will work fine in freshwater and last much longer. Some anglers who fish saltwater occasionally rinse their freshwater motor with fresh water after each trip, which slows corrosion but doesn't prevent it entirely.

Hand Control Versus Foot Pedal

Most trolling motors come with a foot pedal that lets you steer and control speed with your foot while keeping your hands free to fish. The pedal is mounted on the boat floor, and you press it forward to go forward, backward to reverse, and twist it left or right to steer. Foot pedals are standard on bow-mounted motors because they leave your hands available for casting and fighting fish.

A hand remote is a wireless controller that lets you steer and control speed from anywhere on the boat. Hand remotes are useful if you mount the motor on the stern (back) of the boat, or if you want to move around while controlling the motor. Some motors come with both a foot pedal and a hand remote, so you can switch between them depending on what you're doing.

Wireless remotes use radio signals to communicate with the motor, and the range is typically 100 to 200 feet. If the remote loses signal, the motor stops. Most remotes have a backup wired connection, so if the wireless fails, you can plug a cord into the motor and steer with a handheld controller.

Installation and Mounting

A bow-mounted motor is bolted to the front of the boat and is the most common setup for fishing boats. The motor sits in a bracket that lets you tilt it up when you're not using it or when you're running the main engine. Bow-mounted motors keep the boat's bow down and give you the most control when positioning over fish.

A stern-mounted motor is bolted to the back of the boat and is useful if you want to push the boat backward or if your boat's design makes a bow mount difficult. Stern mounts are less common on fishing boats but are standard on pontoons and some larger vessels.

Installation requires drilling holes in the boat and bolting the motor bracket to the gunwale or transom. Most motors come with a mounting bracket and hardware, but you'll need a drill, a wrench, and basic tools. If you're not comfortable drilling into your boat, a marine mechanic or boat dealer can install it for you, usually for $100 to $300 in labor.

Charging and Maintenance

You'll need a battery charger rated for the voltage of your system. A 12V charger won't work on a 24V system, and vice versa. Chargers come in two types: a basic charger that plugs into a household outlet and takes 8 to 12 hours to fully charge a battery, and a fast charger that can charge in 4 to 6 hours but costs more. Some chargers have a maintenance mode that keeps the battery topped off when it's not in use, which extends battery life.

Between trips, rinse the motor with fresh water to remove salt, mud, or debris. Check the propeller for fishing line or weeds and remove anything wrapped around it. If you use the motor in saltwater, spray the exposed parts with a corrosion inhibitor after each trip. Store the motor in a dry place, and if you won't use it for more than a month, charge the battery fully and store it in a cool location — batteries lose charge slowly even when not in use.

Most trolling motors are sealed and don't require oil changes or internal maintenance. If the motor stops working or runs slowly, the problem is usually a dead battery, a loose connection, or a propeller fouled with line. Check the battery voltage with a multimeter, clean the battery terminals, and inspect the propeller before assuming the motor is broken.

Frequently Asked Questions

Can I use a trolling motor on a boat with a main engine?

Yes, that's the most common setup. The trolling motor is for slow, precise movement when fishing, and the main engine is for getting to and from the fishing spot. You tilt the trolling motor up when you start the main engine so the propellers don't interfere with each other.

How long does a trolling motor battery last before I need to replace it?

Lead-acid batteries typically last 3 to 5 years with regular use and proper charging. Lithium batteries last 8 to 10 years or longer. Battery life depends on how often you use it, how deeply you discharge it, and how well you maintain it. Avoid letting a lead-acid battery sit completely dead for long periods, as that shortens its life.

What's the difference between a bow mount and a transom mount?

A bow mount is on the front of the boat and is better for positioning over fish because it pulls the bow down and gives you more control. A transom mount is on the back and is easier to install on some boats, but it's less effective for fishing. Most fishing boats use bow mounts.

Can I use a 12V trolling motor on a 24V battery?

No. Connecting a 12V motor to a 24V battery will burn out the motor's electrical components when ready. Always match the motor voltage to the battery voltage. If you want to upgrade to a 24V system, you'll need to buy a new 24V motor.

Do I need a special license or registration for a trolling motor?

Most states don't require registration or a license for trolling motors alone. However, check your state's boating regulations, as some states have specific rules about motor size or boat registration. Your state's fish and wildlife agency website has the current rules.