T-Pain Is On A Boat: Re: [Electric Boats] Help me decide the most appropriate components...

Wednesday, March 27, 2013

Re: [Electric Boats] Help me decide the most appropriate components...

Paul,

In re planing electric boats, the solution if you want to plane for any distance or length of time is to start with a much lighter hull than you are likely to find on a "conversion". Starting with a hull that weighs over 1000 lbs makes it very difficult. We have achieved very high efficiencies in motors, controllers, transmissions, and props. There is not much room for improvement in these areas. That leaves us with displacement and hull design. If you study hull design options I think you will come to two possibilities. One is to follow the approach of sailing catamarans with their long thin hulls that overcome displacement hull speed limitations with a high aspect ratio of length to beam but of course these are not "planing." The other is to refer back to the designs of the 1920's when 5 to 20 hp outboards were just becoming available. There are a number of very fine semi-displacement and planing designs available. The dominant characteristics of all of these are light weight, length to beam ratios of 4 or 5, and flat or low deadrise bottoms. See, for example, plans by Mower http://www.dngoodchild.com and Atkins http://www.atkinboatplans.com.

I built a 250 lb hull, 19' x 4.5', with 225 lb of LiFePO4 batteries, 60v x 160 Ah, and a Torqeedo 4R outboard. I did 11.25 mph for 24 miles. See http://www.youtube.com/watch?v=7nsjpqWHWpo

I hope this is helpful.

Keep it light!

Ned

On Mar 26, 2013, at 10:49 PM, james4078 wrote:

Here is a little tidbit of advice when trying to convert a planing hull. First they are not designed to cut thru the water like a displacement hull. If you reconfigure the stern and mount a couple electric outboards should do ok.
On youtube there a several outboards converted to electric you could follow suit and copy them. Two is always better than one when out on the water.
Check out my photo album you will see I have done the same conversion with a 25' Regal.
I am not satisfied with the electric outboard on the market so I'm in the process on manufacturing a line for my own use as well as some retail units later this year.

James
--- In electricboats@yahoogroups.com, "Roger L" <rogerlov@...> wrote:
>
> Ok....cPAUL you asked for opinions, here's mine. First off, I should say by introduction that I'm a half-retired engineer and veteran of many a project and not a few boats.......including some self-designed and self-built. Right now I have a 16 foot much modified electric and a 28 foot commercial multihull sailboat.
> I know similar boats, and that Carver looks like a decent boat with a good powerplant which makes it a decent candidate for electrical conversion.
>
> My advice might seem a little strange at first, but it's serious. I would advise to get it running well with the gas engines that it has in it and use it for a season. I'm betting that the things you will learn about the boat in one season will make the electric conversion better, cheaper, and probably faster.
> What do others think?
> Anyone?
> Roger L.
> ..........
> ...............
>
> ----- Original Message -----
> From: cPAUL
> To: electricboats@yahoogroups.com
> Sent: Saturday, March 23, 2013 2:43 PM
> Subject: [Electric Boats] Help me decide the most appropriate components...
>
>
> Hi and thanks for reading this.... I recently aquired a 28 ft Carver Santa Cruz. It has dual 220 hp gas engines I will be removing. I plan on using common parts," as low cost as possible. I have some electrical experience, and will have no problem doing a clean install, does any one have any suggestions for my layout and which parts I should use? I will also have solar cells, wind generators. I was also wondering on the use of 12v altinators being powered on by the prop shaft. The boats total weight with the two motors is approx. 10,500 lbs. does any one have any helpful knowledge or advice??
>
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