Trolling motors
How many amps does a trolling motor actually draw?
Quick answer
A trolling motor's published maximum current draw is the only current figure any manufacturer states, and it runs from 30 amps on a small 12 volt motor up to 56 amps on an 80 pound, 24 volt motor. No manufacturer publishes a draw table by speed setting, only the single maximum figure at full throttle.
A trolling motor's maximum current draw is a published manufacturer figure, the amps it pulls at full throttle, and it is the number that sizes both the battery bank and the fuse or breaker protecting the feed. What no manufacturer publishes is a draw table broken down by speed setting, because a variable speed motor's actual draw at any given setting depends on its own control electronics and prop rather than on a fixed fraction that applies across every model.
This site uses two different kinds of number for that reason. The maximum draw figures below are published, model by model, and do not move. The speed-setting curve further down is a model of how draw likely scales across a typical variable speed motor's range, built for planning, and it says plainly that it is not a measurement of any specific motor. The honest input for a real battery runtime estimate is a clamp meter reading off your own motor, not either number taken as gospel.
On this page
Published maximum current draw by thrust and voltage
This is the one current figure trolling motor manufacturers actually publish: the amps a motor pulls at maximum thrust, full throttle, no other setting.
Published maximum draw runs from 30 amps on a 30 lb, 12 volt motor to 56 amps on an 80 lb, 24 volt motor, and this is the figure that sizes the fuse or breaker on that circuit.
Published figure A published engineering, regulatory or manufacturer figure. It does not change because somebody disagrees with it.
| Thrust rating | System voltage | Published maximum draw |
|---|---|---|
| 30 lb | 12V | 30A |
| 40 lb | 12V | 42A |
| 45 lb | 12V | 42A |
| 50 lb | 12V | 42A |
| 55 lb | 12V | 50A |
| 70 lb | 24V | 42A |
| 80 lb | 24V | 56A |
| 101 lb | 36V | 46A |
| 112 lb | 36V | 52A |
These are the common published values for the mainstream trolling motor lineup. Always check the figure printed on your own motor, since a specific model can differ from the common value at its thrust and voltage.
Three real motors and their published maximum draw
Reading the published maximum draw directly off three real motors in this catalog shows how closely a specific model's own listing tracks the common values above.
A 24 volt, 80 lb thrust Terrova pulls 56 amps at maximum thrust, its own published figure, matching the common value for that thrust and voltage exactly.
Published figure A published engineering, regulatory or manufacturer figure. It does not change because somebody disagrees with it.
| Motor | Thrust and voltage | Published maximum draw |
|---|---|---|
| Minn Kota Terrova 55 | 55 lb, 12V | 50A |
| Minn Kota Terrova 80 MDI | 80 lb, 24V | 56A |
| Minn Kota Terrova 112 | 112 lb, 36V | 52A |
Figures are each motor's own published maximum draw, taken directly from its own listing rather than interpolated from thrust alone.
The speed-setting draw model, and why it is a model rather than a measurement
No manufacturer publishes how current draw scales across a variable speed motor's settings, only the single maximum figure above. The curve below is a planning model built to approximate that scaling, not a measurement of any real motor, and every page that uses it says so.
The planning model assumes speed 5 draws roughly 38 percent of a motor's maximum current, rising to 100 percent only at the top setting, and it is a model rather than a measured curve for any specific motor.
Rule of thumb Boating and fishing convention rather than a published standard. Taught everywhere, useful, and not a specification. Nothing enforces it and no body publishes it.
| Speed setting | Fraction of maximum draw |
|---|---|
| 1 | 8% |
| 3 | 20% |
| 5 | 38% |
| 7 | 62% |
| 9 | 87% |
| 10 | 100% |
This is a model of how a variable speed motor likely draws across its range, not a manufacturer measurement. A clamp meter reading off your own motor at your own speed setting is the honest input for a real runtime calculation.
Applying the model to a real published maximum
Running the speed-setting model against a real motor's published maximum turns the fractions above into estimated amps, which is the number most anglers actually want when planning a trip.
On a motor with a 50 amp published maximum, the model estimates roughly 19 amps at speed 5 and the full 50 amps only at speed 10.
Rule of thumb Boating and fishing convention rather than a published standard. Taught everywhere, useful, and not a specification. Nothing enforces it and no body publishes it.
| Speed setting | Estimated draw (50A max motor) |
|---|---|
| 1 | 4.0A |
| 3 | 10.0A |
| 5 | 19.0A |
| 7 | 31.0A |
| 10 | 50.0A |
This applies the speed-setting model above to a specific published 50 amp maximum. Treat every value except speed 10 as an estimate, not a measured figure.
What the draw figure actually sizes
The published maximum draw is the number that governs two other decisions on the boat. It sizes the fuse or breaker on the motor's feed, covered on the fuse and breaker sizing chart, using the conventional 25 percent margin over the continuous current. It also sizes the battery bank's usable capacity at a real working draw, since a battery's printed amp hour figure is measured at a much gentler rate than a motor pulling 40 or 50 amps ever draws it at. Neither of those calculations should start from the speed-setting model above when the motor's own maximum figure is available and known.
Frequently asked questions
What is the maximum amp draw of a 55 lb thrust trolling motor?
The common published figure for a 55 lb, 12 volt trolling motor is 50 amps at full throttle. That is the manufacturer's own maximum current figure, used to size the fuse or breaker and to judge how hard the motor pulls on a battery bank at full speed. Always confirm the exact figure on your own motor, since specific models can differ from the common value.
Why does the same thrust rating sometimes have a different published draw?
Because draw depends on the motor's prop, its control electronics and its specific design, not on the thrust number alone. Two motors rated at 55 lb of thrust from different manufacturers, or even different generations from the same manufacturer, can carry different published maximum draw figures, which is why this site pulls the number from each motor's own listing rather than assuming one figure fits every motor at a given thrust.
Does a trolling motor draw its maximum current all the time?
No. The published maximum is the draw at full throttle only. At lower speed settings a variable speed motor draws considerably less, though no manufacturer publishes exactly how much less at each setting. The speed-setting model on this page is a planning estimate for that gap, not a measured figure, and a clamp meter reading is the more reliable answer for a specific motor.
How do I measure my trolling motor's actual amp draw?
Clip a DC-capable clamp meter around the positive feed cable while the motor runs at the speed setting you want to check. That reads the real current draw at that moment, which accounts for your specific prop, your boat's load and the water conditions on the day, all of which the published maximum figure and the speed model cannot capture on their own.
Is the speed-setting draw curve the same for every trolling motor?
No, and this site says so explicitly. The curve is a planning model of how a typical variable speed motor's draw might scale across its range, not a measurement published by any manufacturer for any specific motor. Real motors vary from it. Use the model for rough planning and a clamp meter reading for a decision that actually matters.
What amp draw figure should I use to size a fuse or breaker?
Use the motor's own published maximum current draw, not an estimate from the speed-setting model. The fuse or breaker protects the conductor against the worst case current the circuit will ever see, which is the motor running at full throttle, so sizing from anything less than the published maximum leaves the cable under-protected at the one moment it matters most.
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Researched, not professional advice. This page is compiled from published engineering and regulatory figures, manufacturer specifications and owner-review consensus, not hands-on testing. Figures described as a rule of thumb are boating convention rather than published standards, and they are labelled that way wherever they appear. Marine electrical work is not house wiring. Use tinned, finely stranded marine cable, size it for voltage drop and for the ABYC E-11 ampacity table rather than one or the other, and put overcurrent protection within seven inches of the battery positive terminal, because everything between the post and the fuse is unprotected. A lithium battery needs a charger with a lithium profile. Never load a boat past its capacity plate, and remember that canoes and kayaks carry no federal capacity plate at all, so their stated capacity is the manufacturer own figure. Wear the life jacket, and treat early season water as the hazard it is: cold water immersion takes your breath and then your hands long before it takes your core.