Roger,
Put on a 10x6 RC airplane prop ($3.00) and build a fairing (free with shop scraps) for the round tube of a PWM controlled trolling motor and you will double your canoe's range with the same battery.
Lots of details and actual test data here: http://www.boatdesign.net/forums/boat-design/efficient-electric-boat-27996-15.html
Start with post 212.
The whole thread is about a very clever English engineer developing the most efficient canoe propulsion system. The electric paddle incorporates many of the same ideas Jeremy puts forth.
A canoe is probably the most perfectly suited hull for electric power.
Denny Wolfe
www.wolfEboats.com
Thanks for the info. Yes, it does often boil down to battery weight doesn't it? In addition to battery chemistry, there is a limit to how densely that magnetic flux can be packed into a gap space in a motor......at least for motors that can be built with today's production methods. There's a resulting limitation on advances on motor design right now.
You reply made me realize that how things are valued is also important and I'd better figure that one out for my own electric assisted canoe right now.
My value scale starts with the absolute requirements of being very lightweight, quiet running, and long lasting - your requirements may well be different.
After the requirements comes the aesthetics. This one is easy. I've always more inclined to spend my money in support of an interesting or otherwise clever approach to solving a problem. That holds true both in art and engineering.
But not actually being rich, the final cost is always a consideration. I put it at the bottom of this list simply because so far all the possibles seem reasonably priced.
Enjoy! Roger L.
--- In electricboats@yahoogroups.com, "stmbtwle" <stmbtwle@...> wrote:
>
> A $150 electric trolling motor will push your canoe nicely. How big a battery you need is entirely a factor of how far you want to go.
>
> I have a 40# MinnKota on the stern of my 17' fiberglass canoe, and with over 500# of passengers and equipment it'll push us at nearly 5 mph. The two golf batteries are good for 20 mi or more at full speed. The paddles are only there for emergencies.
>
> If weight/cost is more important than range, you can use a smaller battery, even a smaller motor. The smallest motor you can get (about 30# thrust) will easily push the average canoe faster than you can paddle. An ordinary Group 27 marine battery should be good for a couple hours at full speed and all day of goofing around. Even a little U-1 "lawnmower" battery will work though with less range.
>
> You don't even need a motor mount; just clamp the trolling motor to the side of the canoe. You can probably do the whole show for under $200 and about 25#, with a new 30# motor and new U-1 battery (all from Big Box). I would find it hard to justify the expense of a Torqueedo for that purpose.
>
> If this is still too expensive, consider painting your paddle-blades BLACK (less noticeable to wildlife), and learn to paddle without removing the paddle from the water.
>
> Good luck!!!
>
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