# electric boat motors



## HoffaLives (Feb 19, 2007)

a customer has contracted me to setup the electrics on his boat; he's also pulling the perkins and putting in a Thoosa 1700, 96 volt electric motor & 8 8D AGMs. I've done some basic research and the engineering looks pretty sweet, but i'm wondering if anyone has any experience with these? the install looks pretty straightforward, but i'm wondering how it will all work out for the guy as i've never seen one of these set up and running.


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## Freesail99 (Feb 13, 2006)

If you need to just motor in and out of your slip, the electric motor works great. If you need to motor for hours at a time they don't.


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## TSOJOURNER (Dec 16, 1999)

One of my fellow "Rawsoneers" fitted his Rawson 30 with a golf cart motor connected to his original prop. Not high tech at all, but he claims to be able to motor out and go sailing etc.. no problem. But, as already said, don't try to go anywhere. Personally, I am quite interested in the "Torquedo." Wonder if they are considering a sail drive version?


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## Classic30 (Aug 29, 2007)

The other thing to think about is the weight.

Usually an electric motor plus batteries weighs quite a bit more than a small auxilliary.


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## Idiens (Jan 9, 2007)

All you need is an adequate supply of sunshine ....

http://www.solarnavigator.net/transatlantic_21.htm


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## TSOJOURNER (Dec 16, 1999)

Hartley18 said:


> The other thing to think about is the weight.
> 
> Usually an electric motor plus batteries weighs quite a bit more than a small auxilliary.


Very true. In the boat I mentioned, the owner removed ballast from the keel to made room for the batteries. However, he still had batteries everywhere. I think the real trick will be that Li-ion battery technology becomes affordable.
When I googled "Thoosa 1700" I got a bunch of results for mythical creatures. If that the right spelling? People and companies have been building electric cars and boats for at least a hundred years now, if you assume we have a free market this goes to show which system is more practical.

I always like discussing this subject, because I know, someday, somewhere, someone will come up with the silver bullet, and the world will change. But for now, here is a comparison to some commonly available battery types: Prices are a shotgun average from nextag.com. Weight from a spring scale, and approximate.










Of course prices vary.. and these are what I had around the house. Li-Ion equivalent for the Lead Acid seems to anywhere from $50 to $200.


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## fcsob (Apr 28, 2007)

OSSA Powerlite makes a complete conversion for repowering your boat. they range from 20hp to 800hp.Read more @www.ossapowerlite.com/.In septembers Latitudes & Attitudes two boats are featured with electric motors.


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## Idiens (Jan 9, 2007)

Also

http://www.fischerpanda.de/products/eng/154

have a partner company for diesel electric combinations.

It works out almost exactly twice the price of a diesel propulsion system of the same power.


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## ChicagoNewport27 (Nov 21, 2006)

sailboy21 said:


> ...When I googled "Thoosa 1700" I got a bunch of results for mythical creatures. If that the right spelling?


The Thoosa is manufactured by ASMO Marine
http://www.asmomarine.com/2005/asmo_uk/01.shtml


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## ChicagoNewport27 (Nov 21, 2006)

I've been researching this too.

I've been waffling between getting a diesel engine (in the hope of eventually switching over to biodiesel), or to go with an electric inboard, such as the Thoosa 7000 (suitable for my 27' ft sloop).

Since I only am a daysailer/weekender, and usually only cruise less than 50 miles from port, I would feel comfortable with the range afforded by the inboard electric, especially seeing as those nifty Thoosa's can regenerate the batteries when the engine is off by using the slowly turning prop as a dynamo for power generation (this power generation can even work using a feathering prop, but obviously less effectively). Coupled with a solar panel or two, maybe a wind genset, my batteries could basically maintain themselves during the week when I'm not using the boat, which would eliminate the need for a shorepower connection to top up the batteries (my boat is on a mooring, so shorepower is out).

Like I said, I'm basically a weekender, so I dont need to motor for hundreds of miles. I motor in and out of the harbor, or over to the pump-out dock, thats it. If I'm trying to evade a storm, sometimes I'll fire up the motor, however, and that might take more juice than the batteries could provide. If I needed more range with the Thoosa, I could install a diesel generator to top up the batteries, or, if I'm feeling like a cheapskate, I could just use my Honda 2000i gas genny to give me enough juice to maintain the batteries for longer trips under power.

Anyway, since the Thoosa package sells for just over $7k, I'll have plenty of time to debate between biodiesel and electric as I save my pennies for the next few years.

Hopefully, by the time I've made my decision, the cost of batteries and electric marine inboards willhave come down a bit.


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## RXBOT (Sep 7, 2007)

*Electric drives*

There are quite a few alternative electric drive sytems available. Most are expensive. One that isn't is a 48 volt brushless motor with 250 amp sevcon pmac regen controller. This is a 8.5 kw unit equivalent to about 10 hp. $1250. You also need to provide battery bank. One way to provide charging capability is to have small 5-10 hp gas or diesel to drive a 200 or so amp alternater. The nice thing about dc electric motors is you have full torque through the entire speed range. Look up ThunderStruck Motors (Mars brushless sailboat kit) to see above system.


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## tigerregis (Nov 24, 2006)

Google "Solomon Technology" and see for yourself. I saw these at the USSS in Annapolis around 2002/2 and they "work" as driver and generator.


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## Rockter (Sep 11, 2006)

Well, I am learning something new here. 
A diesel electric, for boats?
They use them in trains, to save the complexities of a shaft transmission to all those wheels on the loco.
I am not sure about that 96V stuff, in DC. Seawater-wet hands and you are going to get zapped.
Batteries really don't hold enough poke unless you are in a wee rowing boat, or something, and they will be very heavy, and will have to last a long time to compete with a wee diesel.


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## HoffaLives (Feb 19, 2007)

Rockter said:


> Well, I am learning something new here.
> A diesel electric, for boats?
> They use them in trains, to save the complexities of a shaft transmission to all those wheels on the loco.
> I am not sure about that 96V stuff, in DC. Seawater-wet hands and you are going to get zapped.
> Batteries really don't hold enough poke unless you are in a wee rowing boat, or something, and they will be very heavy, and will have to last a long time to compete with a wee diesel.


buuuut....if you live in an area with plenty of wind, think of running an engine that is almost silent, no vibration, no smoke, and no fuel. also here would be essentially no maintenance, no winterising. no raw water, no heat exchangers.

i don't think you could use a wind generator or solar panels to charge up a bank large enough to run one of these things; you would almost certainly need a powerful, shore based charger to avoid pooping your batteries.


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## sailingdog (Mar 19, 2006)

Generally, liquid petroleum based fuels are far more compact and efficient than electrical energy will be. It is hard to pack more energy into as small a space as a gallon of diesel or gasoline. 

Diesel electric propulsion is very reliable and has been used since WWII, where the German U-boats used it quite well. 

I think it might be hard to justify the cost of a diesel electric hybrid system on a smaller boat. On a larger boat, like the Lagoon 42 catamaran which offers a diesel hybrid, it might make sense. Smaller boats are far too wet for the system to really be reliable, and few can afford the higher weight penalties of a hybrid system.


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## Rockter (Sep 11, 2006)

Well said that man.

...and electrocution.

Try holding a 14V live DC with seawater-wet hands, then multiply by 6.857


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## sailingdog (Mar 19, 2006)

Try 48 VDC... that's what the Thoosa uses...


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## Aleksandar (Sep 11, 2007)

Hi All,

Found this sailboat with Electric Auxiliary on the The Electric Vehicle site:

I still can not post the Links so I am going to type it here in the criptic form, just replace the word "[dot]" with the one:

"www[dot]austinev[dot]org/evalbum/278.html"


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## Classic30 (Aug 29, 2007)

I'd be interested to know how *reliable* electric drive is going to be in a corrosive environment.

Apart from the issues of voltage and sea-water, there is a lot of copper in the motors that may not stay pristine in a marine environment unless it's used continuously - not just getting from the pier to the bay or in emergency situations.

I'm sure it's possible to do something - electric thrusters have been around for years on everything from tug-boats to supertankers - but would you stake your life on it?


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## TSOJOURNER (Dec 16, 1999)

Alternator, starter motor, blowers, thrusters, windlass, bilge pump, water pump. Diesels don't particularly like salt-spray/damp/nasty conditions they live in either.


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## Classic30 (Aug 29, 2007)

'kay... Maybe it's just the batteries then.

Even with flat batteries and the electrics shot, it's possible to hand-crank most small diesels to get them going. Water in the fuel can be strained out and again you're not usually left stranded, but with an electric drive? Not sure what you'd do... swim for shore?


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## sailingdog (Mar 19, 2006)

That's when you start up the diesel genset... doh... why not just go diesel to begin with... 


Hartley18 said:


> 'kay... Maybe it's just the batteries then.
> 
> Even with flat batteries and the electrics shot, it's possible to hand-crank most small diesels to get them going. Water in the fuel can be strained out and again you're not usually left stranded, but with an electric drive? Not sure what you'd do... swim for shore?


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## TSOJOURNER (Dec 16, 1999)

Hartley18 said:


> 'kay... Maybe it's just the batteries then.
> 
> Even with flat batteries and the electrics shot, it's possible to hand-crank most small diesels to get them going. Water in the fuel can be strained out and again you're not usually left stranded, but with an electric drive? Not sure what you'd do... swim for shore?


Not picking on you, but electric motors are amazingly simple, two bearings, and the carbon brushes are the only things to wear out. Windings should last decades. A properly built DC motor will have removable DC brushes:









A very easy repair. And with brushless DC motors.. the only problems would be with the controlling equipment. same thing as your computer hard drive.


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## sailingdog (Mar 19, 2006)

Yes, but without electricity...it's a paperweight. And corrosion can be a serious issue with electric motors, especially on smaller sailboats, which tend to be far wetter than larger ones.

A marine diesel is often simple enough and can run without any electrical system whatsoever. If the alternator goes bad, you do lose electrical power, but most marine diesel will work without electricity-having mechanical fuel pumps and fuel injectors. 


sailboy21 said:


> Not picking on you, but electric motors are amazingly simple, two bearings, and the carbon brushes are the only things to wear out. Windings should last decades. A properly built DC motor will have removable DC brushes:
> 
> 
> 
> ...


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## Classic30 (Aug 29, 2007)

Sailboy, I hate to disagree with you, but the ultra-high-efficiency electric motors used for hybrid-style drives are extremely complicated gadgets using rare-earth magnets and all kinds of other fancy gizmos. Definitely *not* user-serviceable...



sailingdog said:


> ...
> A marine diesel is often simple enough and can run without any electrical system whatsoever. If the alternator goes bad, you do lose electrical power, but most marine diesel will work without electricity-having mechanical fuel pumps and fuel injectors.


I find it interesting that small marine diesel engines (two-cylinder Listers, etc.) are fitted to the majority of the world's lifeboats - craft that are expected to sit for long periods of time without running and then be required to work in an emergency without complaint.

To my way of thinking, anything good enough for a lifeboat should be more than reliable enough on your average cruising yacht..


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## sailingdog (Mar 19, 2006)

Hartley-

Most lifeboats don't have much in the way of electrical equipment.


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## max-on (Mar 30, 2004)

Nigel Calder authored a multi-part article featured in Professional Boat Builder a few months ago discussing the pros and cons of hybrid power, a must read if you are interested in the subject:

http://www.proboat-digital.com/proboat/20070607/

http://www.proboat-digital.com/proboat/20070809/

http://www.proboat-digital.com/proboat/20071011/


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## TSOJOURNER (Dec 16, 1999)

Hartley18 said:


> Sailboy, I hate to disagree with you, but the ultra-high-efficiency electric motors used for hybrid-style drives are extremely complicated gadgets using rare-earth magnets and all kinds of other fancy gizmos. Definitely *not* user-serviceable...











Thoosa has brushes.. but beside the point. Electric motors and electric propulsion are not magical, not super special in any way. The most advanced DC motor on Earth isn't anything more than a case, shaft, bearings, commutator, stator, rotor. It spins.


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## TSOJOURNER (Dec 16, 1999)

Personally I'd wait a few years until fuel cell's go mainstream. Perfect technology for sailboat auxillary drives and all the electrical power you'll ever want. Honda's V Flow engine is only the 2nd generation and it's already getting about 70 mpg in cars.


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## Classic30 (Aug 29, 2007)

sailingdog said:


> Hartley-
> 
> Most lifeboats don't have much in the way of electrical equipment.


Well some do have fixed radios and nav lights... 

... but that's precisely the point. An auxilliary engine that can run without an electrical system is bound to be good news in a marine environment.


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## Classic30 (Aug 29, 2007)

sailboy21 said:


> Thoosa has brushes.. but beside the point. Electric motors and electric propulsion are not magical, not super special in any way. The most advanced DC motor on Earth isn't anything more than a case, shaft, bearings, commutator, stator, rotor. It spins.


Interesting stuff! 

Lessee... Which part of "...regulated by a 4-quadrant motor controller" can be fixed by your average yachtie in a lightning storm??


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## RXBOT (Sep 7, 2007)

*Closed minds*

It seems that a lot of people dismiss electric propulsion without really examining it. If you would research you will find outboards to totally enclosed pod type to saildrive and varying costs. Think of a small daysailer or weekender, where they only need a motor for leaving and returning to the dock. Guess what , no diesel going bad, no gas explosion, no water pumps ,wet exhaust systems etc. You do realize I hope that sailboats are supposed to be sailed (with or without training wheels). Diesels are not supposed to be run for short periods of time at low rpm's which is the way they are used by most daysailers ,weekend cruisers who only need the engine for getting away from or returning to the dock. You could have an electric and a diesel driving a common shaft, and then if you only needed to get away from the dock you wouldn't have to start the diesel.Explore the options you may find some benefits.


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## Idiens (Jan 9, 2007)

max-on said:


> Nigel Calder authored a multi-part article featured in Professional Boat Builder a few months ago discussing the pros and cons of hybrid power, a must read if you are interested in the subject:
> 
> http://www.proboat-digital.com/proboat/20070607/
> 
> ...


Thanks for the reference. It makes really interesting reading, and what Nigel is proposing to test will be even more interesting.


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## TSOJOURNER (Dec 16, 1999)

Hartley18 said:


> Interesting stuff!
> 
> Lessee... Which part of "...regulated by a 4-quadrant motor controller" can be fixed by your average yachtie in a lightning storm??


BIG WORDS BIG WORDS BIG WORDS.. CALL TOWBOATUS AHHHHH!

In all seriousness.. I'm still trying to figure out this:










If anyone an tell me why when I plug in the lamp in "part 4" connected through junction 4 to junction 14 from sending unit 3 the gage 3 connected to junction 11 and sender one goes dead.. 2years and still haven't figured that out.

At least my two cylinder 51.8CID direct mechanically injected reversing gear equipped #2autodiesel internal combustion freshwater cooled engine with green paint doesn't _really_ need all that fancy semiconductor stuff once its running   

almost forgot:









Just trying to make a point


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## Classic30 (Aug 29, 2007)

sailboy21 said:


> ...
> If anyone an tell me why when I plug in the lamp in "part 4" connected through junction 4 to junction 14 from sending unit 3 the gage 3 connected to junction 11 and sender one goes dead.. 2years and still haven't figured that out.


You must have a short somewhere!   

Steam power was good - no electrics at all in those days, but a pity it took so long to get going..


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## Simon123 (Nov 29, 2007)

" Yes, but without electricity...it's a paperweight." -----Much like any engine system without its needed fuel. At current tech and prices electric drive for a sailboat is not a common choice but I'd be suprised if it isn't in 10 years.


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## HoffaLives (Feb 19, 2007)

I think electric engines are a great idea due to their simplicity. there have been comments made about the risks of trusting solid state modules and such, but high quality electronics should far outlast anything mechanical. All things being equal, simpler is more reliable.

The one great drawback currently - and is the same for all modes of electrical transportation - is that the battery technology is really very, very old. This isn't surprising since for 99% of applications, what we have has worked fine. As the demands for electric vehicles of all stripes increases, the research will follow. 

It does seem that for auxiliary power, which generally means occasional use, an electric system would be ideal.


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## jonlgauthier (Apr 27, 2000)

If there was an Internet back when Olaf Evinrude put a gas engine in a skiff, or when Otto Diesel was building an engine to work on kerosene, cooking, and fuel oil, they would have been saying the same think back then: "It's new, it's black magic, just leave me with my oars, cotton sails, wood blocks and hemp sheets! La La La La - I can't hear you!"

Give it time - it will inevitably be cheaper and more efficient to put a constant-rpm diesel mated with an electric drive into a small boat, and that will later be supplanted by a fuel-cell system, then fusion, then probably quantum-foam/dark-energy. Of course, by then we'll be turning into crude oil ourselves!


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