Bowfishing 101: How To Run a Trolling Motor Off a Generator

Learning how to run your trolling motor all night long could be what makes or breaks a bowfishing trip. Trolling motor run times are highly dependent on available battery capacity.

Combine a trolling motor with bowfishing lights and other accessories, and you may watch your run time diminish. Let's discuss what it takes to extend your trolling motor run time by powering it off a generator. 

Special thank you to DFW Bowfishing for the photo of their custom built bowfishing boat with Swamp Eye Light Bars. 

Table of Contents

How to Power Your Trolling Motor by a Generator
Step 1: Determine Power Converter and Generator Based on Trolling Motor Size
Step 2: Wire Trolling Motor, Power Converter, Battery, and Generator
Step 3: Get to Bowfishing

How to Power Your Trolling Motor by a Generator

In order to run a trolling motor off a generator, there are 4 things you need: a generator, converter, battery, and trolling motor.

There will need to be a battery, or battery bank, in-between the trolling motor and converter. The reason for this is because the trolling motor has variable amperage depending on the throttle setting. As the trolling motor is throttled up to go faster, the amperage increases. As it is throttled down to go slower, the amperage decreases.

This rapid change in amperage can be very hard on a power converter, and a battery acting as a buffer will help extend the life of your power converter. 

Common misconception: inverter generators can directly power a trolling motor. This is not entirely true: a power converter is required even though inverter generators can output DC voltage. In reality, inverter generators can only output a very small amount of DC power (typically ~8 amps max). This is good for small accessories such as phone chargers, not so good for bowfishing lights or trolling motors.

Generators are able to put out large amounts of power in the form of AC voltage.

Step 1: Determine Power Converter and Generator Based on Trolling Motor Size

The first step is to determine the maximum amperage draw of a generator-powered trolling motor. If you haven't purchased a trolling motor yet, then keep scrolling down and you will see a table with the recommended pound thrust depending on the size of your boat. 

Let's determine the power required for your generator:

[Power Converter Amperage] X [Power Converter Voltage] X [Factor of Safety] = Total Power Required

where: 
Power Converter Amperage = Listed Amperage on Power Converter
Power Converter Voltage = Operating Voltage (most large power converters have adjustable voltage)
Factor of Safety = 1.25
Total Power Required = Min. Running Watts Needed for Generator

12 Volt DC Trolling Motor

Approx. Max Amp Draw: 50 Amps

• 30 lb thrust can draw up to 30 amps
• Recommended Converter to Run on Generator: 1x PM4 12V 35 Amp Converter 
• Est. Running Watts of Recommended Converter = 450W
• Recommended Generator = PMG Series 2000W Inverter Generator
• 40-45 lb thrust can draw up to 42 amps 
• Recommended Converter to Run on Generator: 1x PM4 12V 45 Amp Converter
• Est. Running Watts of Recommended Converter = 630W
• Recommended Generator = PMG Series 2000W Inverter Generator
• 50 - 55 lb thrust  can draw up to 50 amps
• Recommended Converter to Run on Generator: 1x PM4 12V 55 Amp Converter
• Est. Running Watts of Recommended Converter = 750W
• Recommended Generator = PMG Series 2000W Inverter Generator

24 Volt DC Trolling Motor

24V trolling motors are sometimes powered by 24V batteries, but most often are powered by two 12V batteries hooked in series. You can use 2x 12V power converters or 1x 24V power converter to run these generator-powered trolling motors. It is recommended to use 1x 24V power converter. 

Approx. Max Amp Draw: 56 Amps

• 68 lb thrust can draw up to 42 amps 
• Recommended Converter to Run on Generator: 1x PM3 24V 50 Amp Converter
• Est. Running Watts of Recommended Converter = 1,500W
• Recommended Generator = PMG Series 2000W Inverter Generator
• If running bowfishing lights and other accessories, recommend increasing to PMG Series 4500W Inverter Generator depending on the total power of lights and accessories. 

• 70 lb thrust can also draw up to 42 amps
• Recommended Converter to Run on Generator: 1x PM3 24V 50 Amp Converter
• Est. Running Watts of Recommended Converter = 1,500W
• Recommended Generator = PMG Series 2000W Inverter Generator
• If running bowfishing lights and other accessories, recommend increasing to PMG Series 4500W Inverter Generator depending on the total power of lights and accessories. 

• 80 lb thrust can draw up to 56 amps 
• Recommended Converter to Run on Generator: 1x PM3 24V 50 Amp Converter OR 2x PM4 12V 55 Amp Converters
• Note: when running at maximum speed, the 80 lb thrust trolling motor will draw more than the power converter (recommended 50 amp) can output. The battery will help balance the power in this case, and when the trolling motor is throttle down it will rapidly recharge the battery. 
• Est. Running Watts of Recommended Converter = 1,500W
• Recommended Generator = PMG Series 2000W Inverter Generator
• If running bowfishing lights and other accessories, recommend increasing to PMG Series 4500W Inverter Generator depending on the total power of lights and accessories.

36 Volt DC Trolling Motor

36V trolling motors most commonly use 3x 12V deep cycle batteries connected in series. To power this off generator, it is recommended to connect one 12V converter that is sized properly to each battery. We have provided appropriate converter sizing below for common 36V trolling motor setups. 

Approx. Max Amp Draw: 52 amps 

• 101 lb thrust can draw up to 49 amps 
• Recommended Converter to Run on Generator: 3x PM4 12V 55 Amp Converter 
• Each converter will be individually connected to batteries as 12 volts, they should not hook together in series to form 36 volts. 
• Est. Running Watts of Recommended Converters = 2,475W
• Recommended Generator = PMG Series 4500W Inverter Generator

• 112 lb thrust can draw up to 52 amps
• Recommended Converter: 3x PM4 55 Amp Converter
• Each converter will be individually connected to batteries as 12 volts, they should not hook together in series to form 36 volts. 
• Est. Running Watts of Recommended Converters = 2,475W
• Recommended Generator = PMG Series 4500W Inverter Generator

Table of Trolling Motor Outputs

Extra Tip: How to Find the Trolling Motor that Fits Your Bowfishing Boat

Step 2: Wire Trolling Motor, Power Converter, Battery, and Generator

The trolling motor will have a positive (typically red wire color) terminal and a negative (typically black wire color) terminal. These will connect to your battery, or batteries, depending on the size of your trolling motor. 

The power converter will connect to your battery, or batteries, in the same fashion. Once connected, the power converter will then plug into the generator with the 120V AC plug that comes standard on most generators and converters. 

Let's walk through this setup depending on the voltage of your trolling motor. 

12 Volt DC Trolling Motor

• 12 Volt DC Trolling Motor -> 12V DC Battery
• Generator -> 12V DC Power Converter -> 12V DC Battery

How to Connect 1x 12V Batteries in Series for 12V Trolling Motor:

• Battery 1 positive terminal is connected to positive terminal of trolling motor.
• Battery 1 negative terminal is connected to negative terminal of trolling motor.
• Note: same battery connection applies for power converter as trolling motor. 

24 Volt DC Trolling Motor

• 24 Volt DC Trolling Motor -> 2x 12V DC Batteries Connected in Series
• Generator -> 24V DC Power Converter -> 2x 12V DC Batteries Connected in Series

How to Connect 2x 12V Batteries in Series for 24V Trolling Motor:

• Battery 1 negative terminal is connected to Battery 2 positive terminal.
• Battery 1 positive terminal is connected to positive terminal of 24V trolling motor.
• Battery 2 negative terminal is connected to negative terminal of 24V trolling motor. 
• Note: same battery connection applies for power converter as trolling motor. 

36 Volt DC Trolling Motor

• 36 Volt DC Trolling Motor -> 3x 12V DC Batteries Connected in Series
• Generator -> 3x 12V DC Power Converter -> 3x Individual 12V Batteries, Not Connected in Series. 

How to Connect 3x 12V Batteries in Series for 36V Trolling Motor:

• Battery 1 negative terminal is connected to Battery 2 positive terminal.
• Battery 2 negative terminal is connected to Battery 3 positive terminal.
• Battery 3 negative terminal is connected to negative terminal of 36V trolling motor.
• Battery 1 positive terminal is connected to positive terminal of 36V trolling motor. 
• Note: battery connection for trolling motor does not apply to battery connection for power converter. 12V power converter must be connected to batteries individually, while trolling motor will be connected to batteries in series. 

Step 3: Get to Bowfishing

You're rigged up and ready to go, with your trolling motor all powered by a generator. Next up, have you thought about running your bowfishing lights off a generator? Check out our bowfishing tips for more information on making your bowfishing experience easier. 

Outrigger Outdoors is your trusted source for industry-leading bowfishing lights. Check out our selection of Swamp Eye Bowfishing Lights, capable of adjusting on the fly to increase visibility in clear or muddy water. It's time to put more fish in the boat. Shop Swamp Eye Bowfishing Lights today.