e-outboard fishing boat project

Hi,

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edit: I changed the plan and will convert an old outboard motor to electric. I replaced the combustion engine with a ME0913 motor.
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I think about building two (separate) electric outboard motors for my future fishing boat (details: http://www.hiroshajo.hu/english/model/kmaxixtra.html) to get faster to the spots than with the trolling motor and inflatable boat I'm using now.

I would use the follwing components:

Motors: 80100 outrunner, will rewind them for 70kv and install halls
Controllers: 24 x 4115 fets sensored infineon
Gearing: Neugart WPLE 60 (1:5) gearboxes (underwater)
Battery: 30s A123 (100V, 12kwh)
Props: maybe the props which are installed on the torqeedo cruise 4.0 models. Designed for about 20km/h with 1300rpm.

I expect 3-4 kw continous from each motor (with water cooling of the mounting plate) and hope that the boat will reach planing speed.

What do you think, is planing realistic or should I focus on the max. hull speed?

tef

The speed of the hull will be the determiner.Each hull has characteristics that will determine planing speed. This speed will vary with weight. The manufacturer should be able to tell you whether the hull will plane with the speed/weight you plan to have I think you are on the right path keeping near the designed prop speed. They are most efficient at one speed and efficiency is not linear with rotational speed, it drops off like a rock. Two drives seem like the right direction with your requirement to push more weight than the torqueedo was designed to push (thus the props). Keep us updated on how it works it out.

thank you, I will keep you up to date.

If you can keep the boat weight right down, then what you propose might well get you on the plane. Power consumption will be pretty high at planing speeds, though, far, far greater than when running at displacement speed.

You can get away with a fairly small amount of power to run a boat at quite reasonable speeds with a bit of careful design. Boats designed for rowing are usually pretty good, as a rower can only deliver around 100 to 120 watts. This may conflict with your need for stability when fishing, though.

The Torqeedo props are a good choice, as they are probably around the best off-the-shelf props available in terms of efficiency. Ordinary outboard and trolling motor props tend to be fairly poor as a rule.

Interesting project, I'd be keen to see how it works out.

It's time to give a little update on the electric boat project.

I have bought a used 4.1m fiberglass sportboat hull.
Apart from the transom, which needs to be rebuilt, it is in a good shape for its age and will hold up fine for the next few years.
The saved money compared to the boat in my first post will be invested in more battery capacity, probably 20kwh total.

I changed the original plan and use the shaft of an old 40hp johnson combustion engine combined with a 30KW Motoenergy Me0913 brushless motor and a hydraulic trim unit to get the boat into plane.
The motor is already mounted on the shaft.

I am still unsure which controller to use.
I would buy a sevcon if it could get configured without the expensive programming device in an easy way.
Maybe a kelly would be an option but I have doubts about reliability wich is very important on a big river with ship traffic like the danube.

The motor has two stators.
Is it reasonable to use two controllers and connect them both to one set of hall sensors and one throttle?
Two EB236 controller with 36 x 4115 mosfets each (110V battery voltage) should deliver the needed power (2x8kw continous) without touching the limits?
Even if one controller fails, there is still the second one to get me to the riverside.
Watercooling the fets, if necessary, would not be a problem since I did not remove the impeller from the shaft.

Hopefully, the weight is not too much with all those batteries (~250kg). The motor with trim bracket weights ~60kg and the boat itself about 200kg.

Maybe I will mount one of the 80100 outrunners with a WPLE60 and a torqueedo prop on the bow and use it as an efficient trolling motor for low speeds during fishing.

Cool project. Did you add more battery capacity? I was wondering why the batts weigh so much. That's only 48wh/kg.

This is a Forum that I have been on for many years. They have a ton of experts and good information;
http://groups.yahoo.com/group/electricboats/?yguid=206608459

tef said:

Hi,

I think about building two (separate) electric outboard motors for my future fishing boat (details: http://www.hiroshajo.hu/english/model/kmaxixtra.html) to get faster to the spots than with the trolling motor and inflatable boat I'm using now.

I would use the follwing components:

Motors: 80100 outrunner, will rewind them for 70kv and install halls
Controllers: 24 x 4115 fets sensored infineon
Gearing: Neugart WPLE 60 (1:5) gearboxes (underwater)
Battery: 30s A123 (100V, 12kwh)
Props: maybe the props which are installed on the torqeedo cruise 4.0 models. Designed for about 20km/h with 1300rpm.

I expect 3-4 kw continous from each motor (with water cooling of the mounting plate) and hope that the boat will reach planing speed.

What do you think, is planing realistic or should I focus on the max. hull speed?

tef

Click to expand...

Gordo, thanks for the link.

John in CR said:

Cool project. Did you add more battery capacity? I was wondering why the batts weigh so much. That's only 48wh/kg.

Click to expand...

Yes, I will use 20kwh instead of 12. The goal is to hold 30km/h for an hour.

Hi tef,
The temptation is to always want to go fast no matter what the power source or vehicle. If one can afford it, why not? There are clubs in the Northwest of the US who have been racing e-outboards for over 20 years. They improve every year. But to my way of thinking they are not efficient enough. I want the propeller connected directly to the shaft of the motor, with no belts, gears or chains in between. I want a large diameter prop with a small diameter lower unit. With the last two commercial boats I built, 37' & 40', I put the largest props possible on them and was 1-2 knots slower than identical boats, when we were running empty. My props were 25% larger in diameter, using less pitch and greater reduction gears than the other guys. It only took 1 ton of load, to knock the fast guys off plane. I could still plane with 2 tons. The only time they had the advantage, was when travelling 100's of miles empty. All of my decisions were based on the advice on an old Scot, who built all our propellers. I took his advice, they did not.
With electric, it seems the Torqueedo is a good start, although there are other props for this motor which are even more efficient. A very light, long displacement hull which is pointed on both ends is my goal.

http://www.boatdealers.ca/reviews/boats/bruce/bruce-22-classic-electric-launch.aspx?LangID=1

Keep us informed of your progress.

tef said:

Gordo, thanks for the link.

John in CR said:

Cool project. Did you add more battery capacity? I was wondering why the batts weigh so much. That's only 48wh/kg.

Click to expand...

Yes, I will use 20kwh instead of 12. The goal is to hold 30km/h for an hour.

Click to expand...

Hi gordo,

I know that this setup will not be very efficient but that is ok for me, as long as I get a range of at least 20km at a reasonable speed.
The battery bank will be used primarily in my photovoltaic system, so I need that much capacity anyway.

I wish that I could install a larger prop but the max. diameter is 10.5 inch because of the limited room to the anti-cavitation plate.

tef,
You might consider eliminating part of the cavitation plate as it is only needed with high horsepower pushing a heavy boat onto plane. You can also greatly increase the push at displacement speed by using a ring around the prop. This style, which one can make; http://www.propguard.net/
It must fit close to the tips of the prop to produce an efficiency gain.
There are many theories as to the number of blades which are best for any application. I have always stuck to 2 blades for small light boats, but don't have a clue if this is best?

tef said:

Hi gordo,

I know that this setup will not be very efficient but that is ok for me, as long as I get a range of at least 20km at a reasonable speed.
The battery bank will be used primarily in my photovoltaic system, so I need that much capacity anyway.

I wish that I could install a larger prop but the max. diameter is 10.5 inch because of the limited room to the anti-cavitation plate.

Click to expand...