# electric trolling motors for small sailboats?



## thebrakes (Dec 11, 2003)

i recently purchased a san juan 21, 7'' beam, weighs 1250 lbs. i am considering powering it with electric trolling motor(s), the kind typically used by fishermen for keeping quiet. 

naturally, this is not a permanent arrangement. i intend to install a small gas outboard in a short while, but need a quick power fix to move the boat and get me around in the meantime.

has anyone tried this before? will the engines produce enough power to get me through the water?

i have access to some really cheap electric motors, which is why i am even considering this. any guidance would be most appreciated.


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## TSOJOURNER (Dec 16, 1999)

I have powered a 18'' daysailer with a 1.2hp outboard. It worked OK. There was a guy that powered a 25'' sailboat with a simular motor. He moved slow. Unfortunately the trolling motors are rated in pounds of thrust and the small outboards in horsepower. 
In short I think that it would work in light winds to move you a short distance in and out of the dock. I''ve seen some bass boats moving along at several knots with their trolling motors.


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## SailinJay (Dec 6, 2002)

The sailing school I went to allowed you to charter their school boats, Tanzer 22s, for day sails. They had 12 boats or so, but only three outboards. If you didn''t get there early, you had to get towed out and back. So I pulled a trolling motor off of my small aluminum fishing boat (35-pounds of thrust) and brought it with me for the Tanzer. Got me out away from the dock and out on the water, and back with no problem. In later years I used it on a Catalina 22 with similar results. You didn''t move fast, but even in a blow you could make forward progress.

They make 55-pound thrust saltwater motors and I was considering one of those to replace an old Johnson 9.9 that was a bit finicky. Was motoring out next to a J-24 that had one of them, and the guy was moving along very smartly, much faster than I did with the smaller motor.

The 55-pound thrust motor is used with a 12-volt deep cycle battery. If you rig up a 24-volt system, you can get electric motors that have much higher thrust. These would be more than enough for a small sailboat.


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## e-27 sailor (Oct 1, 2003)

I power my Express 27 (2450#) with a Honda 2HP. The motor only weighs 28lbs and burns 1qt/hr. In protected waters, I can motor at about 5-6 knots, and it''s never failed to start.


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## gstraub (Sep 25, 2002)

Quite a while back I owned a Holder 20 that I think weighs about the same as your San Juan. I used an old Sears trolling motor and a marine battery as an auxiliary. It worked fine. I eventually moved up to a 2 HP Honda outboard, and that worked even better.

Gerhard


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## StanLee (Dec 29, 2003)

I currently use a walmart bought 50lb thrust electric to push my 18Ft trimaran around. works great, very quiet no fumes and just needs an occasional battery charge.
A friend has alos used one to push his Oday 20'' as well.

Stan


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## Moonlightuser (May 21, 2008)

I have a 22' US Yacht and I want to go down from an 8HP 2 stroke to a 2HP Honda 4 stroke and I'm wondering if it will help at all when the winds pick up and I decide to try and head into the wind to lower my sails. 8 and 9.9 HP motors are just too heavy and that's what I've been using for over 10 years. I like everything about Hondas little 2 except I know I'm loosing a lot of power and my only concern is what happens in a heavy storm?


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## sailingdog (Mar 19, 2006)

Moonlight-

You'd be much better off with a 3.5 HP or 5 hp four-stroke, since they're relatively light and a good deal more powerful than the 2 HP Honda, which has no transmission IIRC. Not having a transmission can mean problems when trying to maneuver at slow speeds. 

The 3.5 HP Tohatsu is about 40 lbs. with a full tank, and I like the one I have very much. 

Thebrakes—

As a stop-gap measure, the electric trolling motor might work fairly well, provided you remember to charge the batteries regularly, don't run them completely flat, and only have short distances in relatively calm waters to move the boat over.


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## Freesail99 (Feb 13, 2006)

I was on a capri 22 with a 2 hp honda on the Delaware river which has a strong current, it did "ok", not a world beater. If I was in any coastal conditions, I would like a bigger motor, perhaps a 3.5 hp ?


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## Moonlightuser (May 21, 2008)

Thank you. Looks like the Tohatsu you have is the 2 stroke and that they do not make anymore. They do have a 4 stroke though and their prices look better than Honda and Yamaha.

]


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## tjaldur (Mar 1, 2008)

I use a 30 pound pushpower trolley (probably the smallest) on my inflatable dinghy. The consumption is about 230 watt. I use two 80 amp batteries. One in the dinghy, the other on board the ship for charging. One charge last for 4 hours use. For charging I use a 2,5 KW gas-generator. 

If were not that I also need to use the generator for a whole lot of other charging purposes, like charging the batteries for use with refrigerator, TV, computers etc. I would probably spend more gasoline, make more noyce charging the batteries for the dinghy than i would using a small 5 -6 HP two-stroke for propulsion.

I believe you need to make an input/output calculation of the charge/use of current. It is the charging capacity that will define the distance of "the point of no return".


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## eMKay (Aug 18, 2007)

I had one on my Siren, a 36lb thrust motor attached to a group 24 battery. It worked just fine, pushed the boat at 3.5mph.


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## thekeip (Aug 8, 2007)

I thought this thread had something to do with electric motor propulsion?
Howard


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## Coolmobility (Jul 11, 2010)

*I'm interested in electric trolling motor too*

I have a 25' fixed keel Quarter Tonner weighing 1600 kg and am seriouly considering using a 80 lb thrust 24V trolling motor. These motors have up to 1140 Watt motors, direct drive without gearbox losses so would probably equate to about 2 HP (1500 Watts, less gearing losses).

Would only be used for moving around pens and getting in and out of Yacht Club marina. I intend to eventually replace my 6HP Volvo in-board with a 5KW electric, but that will take time. I'd be interested in others using these great little motors for larger yachts.


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## chris31519 (Nov 25, 2009)

Where I sail is a nature preserve and no gas engines are allowed. On my Elan 19 I have a 550W Minkota E55. This is the most powerful 12V trolling Minkota there is but it's still only about 2/3 of a HP.

I flat water I can get 2.5 knots but it will not punch into more than a force 3 headwind. I only use it to get back if becalmed. There are boats with several kW electric motors but these are hugely expensive.

Unless you are on a lake or very sheltered waters with never any current, forget it. Buy a gas O/B.


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## bobmcgov (Jul 19, 2007)

Recognizing this thread is old times two.... We use a Motorguide 40# VariMax troller on our SJ21 (which if you put it on a truck scales, actually weighs more like 1500# empty.) This saltwater motor has digital variable speed, rather than the usual rheostatic control; so you can expect up to double the run time at partial throttle. It pushes the boat with full gear and two people at 3.2kts, but it's not driving into any headwind above 18kts (we know that from experience). 40# of thrust is pretty close to 1 hp -- good for maneuvering in decent conditions, but no more. Very much an auxilliary engine.

The advantages:

1. Quiet. So quiet you have peer over the transom to make sure it is running.

2. Weight. Easy to lift on and off the mount (which helps w/ security, too). The SJ21 can tolerate weight in its bow but it HATES weight on the transom. It will squat. The trolling motor weighs 18lbs, compared to over 40lbs for a 2.5 hp 4-stroke with long shaft. Of course, the group27 battery weighs another 60 lbs, but it lives right beside the keel box in the center of the boat and actually adds righting moment.

3. 360 degrees of rotation, slender on the transom, doesn't obstruct cleats or interfere with the rudder.

4. No worries about carburetor gumming, ethanol, impellers, or storing gasoline on the boat. I HATE gasoline on a boat.

5. Trollers are intended for steady, low-speed propulsion, so their RPM range and propeller designs are a good match for sailboats.

6. Price. Digital saltwater troller, big battery, and all fittings cost less than half what a Mercury 2.5hp would.

Disadvantages:

1. Not much thrust, unless you buy a Torqueedo.

2. Never sure about battery capacity. While overall maintenance is lower on the troller than on a gas outboard, you must watch water levels, terminal corrosion, and replace batteries occasionally.

3. Requires big wires and big amps, which does add a fire hazard. Not as bad as gasoline, but real nonetheless.

4. Our particular motor model has some quirks. When run for a long time on hot days, the urethane-potted variable speed control may overheat; the motor will run at half-speed, or not at all, to prevent melting. Motorguide assures me this is not a design _flaw_ but a design _feature_. I feel better about that.:/ It also, under these same conditions, may continue to run at low speed *even when the tiller control is positively clicked off.* Motorguide at first claimed they'd never heard of this phenomenon; when I pointed to numerous internet complaints about motors that won't turn off, they conceded such a thing MIGHT be possible but is easily addressed by yanking the plug out of its socket.

I feel not-so-good about that.

On the whole, I'm satisfied with the troller as an auxilliary. But if we went to Catalina Island again, I might borrow a 3hp gas motor. Or not. We added oarlocks to the coamings; they work well in concert with the motor.


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## Coolmobility (Jul 11, 2010)

Thanks For that feedback. Very informative and valuable.


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## bljones (Oct 13, 2008)

I am not a huge fan of electric motors, but a 17' Siren in our marina has been slippig in and out of the harbour this season with a Minn Kota trolling motor on the transom, and I was looking for a new propulsion system for our small dinghy, so I decided to try electric, for a couple of reasons:
1. Our dinghy is LIGHT. TOO light. ie, tippy. In fact, too tippy to safely load into from the dock, as our dock is 3 feet above the floor of the dinghy. So I figured the added ballast of a group 27 battery would help, and I liked the fact that the battery ballast was movable to make allowances for payload.
2. Ergonomically, our boat was too small to start our 2 stroke OB. The pull was too long, and you ran out of boat before you ran out of rope. When you did get the OB started, with no neutral, you better make sure you are pointed in the right direction. 

So, this wekend we strapped a Minn Kota 24 lb. thrust trolling motor on the transom, and SWMBO took it for a test drive. The results were mixed.
When it ran, it ran well, and powered the dinghy along respectably.... BUT, our marina has a big issue with weeds... and so does our trolling motor. On the shakedown cruise, my wife repeatedly had to clear the prop, as it simply did not have enough "oomph" to get rid of the wad of weeds that it collected. Maybe a "weedless" prop will help. We plan to install one next weekend. 

On the upside, , SWMBO did like the quiet, the fact that the motor had a reverse, and the added stability provided by the group 27 ballast. I like the light weight of the motor and the fact that we don't have to carry an additional tank of fuel. The downside is that that ballast also cut into available legroom, which reduces the usability of the boat as a 2 person conveyance.

The verdict? The jury is still out. With a little dinghy frame redesign work, we might be able to make the battery stow a little better, and with a new prop weeds may not be an issue. I'll report back with an update next week.


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## slrrls2000 (May 13, 2009)

*Minn kotas RT202/em*

The Minn kota RT202/em can be used at variable voltage and will deliver a fine force behind your boat. The RT160/em and the 101 should be exceptional power. These are salt water trawlers and the prices are in line or as much as half in line with gas motors. And to top it all off ad a folding prop and your good to go.

Specifications for Minn Kota's saltwater Engine Mount motors: Model Motor Configuration Maximum Thrust Volts/Max. Amp Draw Recommended
Boat Length MSRP
RT202/EM Dual 202 36/98 22' - 26' $1499.99
RT160/EM Dual 160 24/116 20' - 24' $999.99
RT101/EM Single 101 36/49 18' - 22' $899.99
RT80/EM Single 80 24/58 16' - 20' $799.99
RT55/EM Single 55 12/50 14' - 18' $599.99

Also search youtube for minn kota and electric boats

These guys sell a 20hp kit that will work as an inboard replacement or outboard.
They also have an electric outboard.
Electric Motorsport :: Marine
Thats 20 horsies inboard for 1400.00 think about it.


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