Electric Propulsion

[seandepagnier]

Hi,

I have found a great deal on a sailboat, partially because there is no engine! I would not consider using gas power anyway, so I am glad, but I am curious at the possibility of electric.

The boat was an inboard, so the propeller and shaft is intact. I want to hook up an electric motor of 1-2 hp. I am thinking a car starter motor from a junkyard will work, but the rpm is probably way wrong. Also, I am afraid of killing my batteries this way.

The other consideration is I would like to generate power when under sail from the same motor.

It looks like I'm going to get 100-200 amp hours of 12 volt lead acid batteries.. but I really would like a vanadium flow battery. Does anyone know where I could get one?

Any suggestions helpful. I'm on a fairly tight budget though.

[fareweather]

car starter motor from a junkyard

No way

You'll need a diesel genset plus elec motor plus wiring and controls.

I'm on a fairly tight budget though.

Don't need to go any farther than that.

[seandepagnier]

Originally Posted by fareweather

No way

You'll need a diesel genset plus elec motor plus wiring and controls.

Don't need to go any farther than that.

So the electric motor from a diesel generator would work? Maybe the motor from an electric scooter.. I don't care if it's underpowered.

I'm also wondering if I can rig up my bicycle to directly drive the propeller.

[Chief Engineer]

Look up diesel-electric tug.
Or diesel-electric locomotive

[aspiringsailor]

I can already see everyone asking what size boat you plan to peddle.

[TaoJones]

Uhm . . . what size boat do you plan to peddle?

TaoJones

[Chief Engineer]

Get a small Honda Genset 1 KW....with a twelve volt trolling motor

[Ex-Calif]

1-2 hp electric motor? What size sailboat? What will be the duty cycle of the propulsion?

If it's just on and off the dock then I'm with the Chief. Get a trolling motor and be done.

By the time you get batteries, wiring, controls and adapter plates you will be very close ot the cost of a trolling motor anyway.

[fareweather]

http://www.ossapowerlite.com/

The electric motor is only one part of the system, you also need a power source and a way to charge it. For ex.: trolling motor, battery and a genset or solar panels or 120v plug in or a bike. The electric motor is not a stand alone unit.

I remember reading about a guy who set up a bike to charge a battery. It was great for exercise, not so great for charging. A human can only generate about 1/2 hp so it's a labor of love.

Hooking it directly up to the prop would be cool but I'm guessing you would have a logistical conundrum when you also needed to steer If you get it rigged it up to turn the prop and hook your tiller up to the handlebars I really want to see a pic (seriously, that would be cool!)

[Chief Engineer]

"Don't be meddlin when I'm Pedal'n"

[seandepagnier]

The boat weighs about 8,000lbs...

Originally Posted by fareweather

Diesel-electric marine propulsion systems and accessories.

The electric motor is only one part of the system, you also need a power source and a way to charge it. For ex.: trolling motor, battery and a genset or solar panels or 120v plug in or a bike. The electric motor is not a stand alone unit.

Maybe I'm weird, but I would not consider using a generator.. I hate burning gas.

I will have solar, but only 45 watts or so to start out. I may get a wind generator, but the 400w one (which produces 50 watts in 12 knot winds) is something like $700. I'm getting the boat for $1000, so it seems crazy to do that.

I remember reading about a guy who set up a bike to charge a battery. It was great for exercise, not so great for charging. A human can only generate about 1/2 hp so it's a labor of love.

Yes, that would be very inefficient, and even more inefficient because I'm planning on using brushed motors.

Hooking it directly up to the prop would be cool but I'm guessing you would have a logistical conundrum when you also needed to steer If you get it rigged it up to turn the prop and hook your tiller up to the handlebars I really want to see a pic (seriously, that would be cool!)

Yes, I wonder how fast it would go... I could hook up the handlebars to the tiller with ropes and pulleys though..

[David M]

For small boats, diesel-electric technology is still in its infancy. More bugs need to be shaken out and there needs to be more standardization. Prices need to come down and the many manufacturers making these systems need to be shaken out. Buying a hybrid system now would be much like buying the first version of anything. The next versions will be cheaper, more reliable and better. If I were to making that choice I would wait and go with more refined forms of propulsion for now.

[sandinmytea]

It seems like you're thinking about doing something that I was considering doing as well.

I started doing some of the math on it. What it comes down to, is that unless you are absolutely sure you will nearly NEVER use the engine, you will not be able to get a decent amount of power when necessary, for as long as necessary. without having a severe number of batteries available. That means a prohibitive amount of weight, plus the cost of all those batteries. What's worse, is that the systems which MIGHT provide steady recharge power (we're talking GREEN of course) are all fairly expensive.

There are some options. Making a cheap, unreliable wind generator out of a discarded treadmill generator is one way. But its been done apparently. You can do the same with a towed generator array (to generate while you are sailing) but keeping it going without corroding itself to death is a big mission. Solar is another option, sounds like you're already on board with that, but its limited in what it can provide.

How about this: sculling the boat? Or even better, create an electric device which sculls the boat for you! Look up sculling, its interesting.

Its a tough thing. There's this torqueedo outboard that's been developed that has promise, but the reality it is expensive and fairly unproven (looks too plastic-y to me). Hey, anything can be done! We went to the moon, but not on a limited budget. I've bitten down hard and accepted that until I have a primo cruising kitty, my boat won't be motoring in under silent green electric power.

[Intentional Drifter]

Torqueedos are meant for small, light dinghies. It won't last long pushing 8000 lbs. For a windgen, on the cheap, check out:

YouTube - How I Build A Wind Turbine - Building Wind Turbines At Home

Seriously, though, you're really better getting a conventional engine. What was originally in it? You might be able to find a rebuild (or rebuild yourself) that wouldn't be too bad.

Oh, and I hate to rain on your parade, but just because there's a shaft and a prop, doesn't mean they're actually functional. Corrosion, electrolysis, marine growth, being run out of alignment, cutlass bearings -- oh, the list goes on and on.

Have you learned what "B O A T" stands for? "Break Out Another Thousand". They're called "boat-units". But, congratulations! You got a boat for 1 boat unit. Very few of us around here can say that. May she bring you much joy. You'll have the pride of accomplishing things.

Oh, and welcome to the forum!

ID