View Full Version : Speaking of electric boats

05-31-2002, 02:43 PM
I bought a bunch (12-15) of electric golf carts at a military surplus auction some time ago. Anybody out there got any experience with using these 36 volt motors in a boat?

Wayne Jeffers
05-31-2002, 03:08 PM
No first-hand experience, but I read somewhere, years ago, of this golf-cart-to-marine application having been done successfully.


05-31-2002, 03:11 PM
Came home with 12 - 15 golf carts, eh? Not married, are ya.



Tom Dugan
05-31-2002, 03:49 PM
Here (http://www.electricboat.com) are the folks who know electric boats.


Tom Dugan
05-31-2002, 03:54 PM
FYI, Ecycle (http://www.ecycle.com/ecycle_boat_propulsion.htm) has come out with inboard electric drives, with plans for electric outboards by 3Q02.


Tom Lathrop
05-31-2002, 04:21 PM
I believe an article appeared in Boatbuilder a couple years ago on this subject. It was by Glenn-l and they used the lower unit of an outboard under the hull and a golf cart motor on the inside. I think Glenn-l sells plans also. Looked like a decent idea to me.

05-31-2002, 04:58 PM
Electric power vehicles can be real fun
it's all those extention cords! :D

Seriously, I helped build a solar power car in college, real :cool: stuff

The folks listen about were at the Maine Boat Show, looked like some real nice pieces.

and you can go in lakes that forbid gasoline/diesel engines when your done!

On Vacation
05-31-2002, 05:14 PM
Here is a guy that has made it work for ten years.

[ 05-31-2002, 06:14 PM: Message edited by: oyster ]

05-31-2002, 06:18 PM
Hey guys I really 'preciate all the links. Think I'll see how much trouble it is to get one of the things out and then see if I can figure out how it works. Seems to me it would be great in a small wood skiff (maybe like a Swan Nez Pierce).

Wayne Jeffers
05-31-2002, 06:41 PM
For electric power, a skiff with more rocker, like Swan's "Little Gem" would be better than a planing hull (with a flat run aft) like Nez Pierce. Electric power would not be enough to get Nez Pierce on plane, and you'd be dragging water behind the emersed part of the transom.


05-31-2002, 08:25 PM
Excellent point Wayne. Now everyone knows I'm no Navel Arkatech. :rolleyes:

ken mcclure
05-31-2002, 10:32 PM
Pelican must have a GREAT place to visit. He trades "a few" guns and trinkets and gets a 40' boat. Now he's got a dozen golf carts. Something tells me that there's probably an old time machine in the corner there, covered with an old tarp and some cobwebs.....

06-01-2002, 09:40 AM
Yup Ken, we got's some more junk. I'm an accumulator. :D

Scott Sawtelle
06-01-2002, 08:42 PM
In the March/April issue of Water Craft magazine there are two sailboats designed for an electric auxilliary. One of them, a design by Antonio Dias called BitterSweet is actually designed for a "4 hp golf cart type engine". The 22+ foot, 3000 lb boat is supposed to cruise at 3-4 knots for 8 hours with 12 100 amp hour batteries. Alot more people seem to be going this way these days.

06-01-2002, 09:13 PM
I wonder, are all golf cart motors rated about 4 HP? :confused:

06-02-2002, 10:35 AM
Good grief Scott. How much do 12 100 ampere/hr batteries weigh? At what voltage? I am willing to guess that they would add over ten percent to the boat's weight.

Scott Sawtelle
06-02-2002, 12:17 PM
The weight and voltage isn't listed. The boat in question is shown on the front cover. The owner/builder used lead acid deep cycle 6 volt batteries, hooked up to provide 36 volts. The batteries are placed low on both sides of the centerboard case. They do weigh alot, but they need to, They're the ballast! Pretty neat, getting all of that electricity out of your ballast.

06-02-2002, 05:29 PM
I think with that information I can give you a rough estimate of weight. Each battery is 100 amp-hours and 6.0 volts, according to your last post. That is 600 watt-hours per battery, and there are 12 of them, which makes for 7200 watt-hours for the twelve.

Lead-acid batteries have a specific energy of about 15 to 20 watt hours/pound. I believe that comes out to be 7200/20 = 360 pounds, taking the more favorable number for specific energy.

There are batteries that have much better specific energy values, but would guess they cost a lot more.

One horse power is 746 watts, therefore you battery pack would deliver almost ten horse power hours, (1.0 hp for 10 hrs, 10 hp for 1.0 hr, etc) if everything was working at 100% efficiency, which it won't.

06-03-2002, 06:44 AM

I used to build these with used golf carts. Years ago I worked at a small shipyard in RI. that built these launches in either gas, steam, or electric versions. For the electric ones the owner of the yard sent me up to providence to buy a bunch of old used golf carts. I stripped the needed parts & would then install them in the launches. - Worked pretty well.

oh yes, to save the guesses I'm behind the camera in the pic. ;)

[ 06-03-2002, 07:45 AM: Message edited by: nedL ]

06-03-2002, 04:38 PM
Ned, what size prop did you use with them? :confused: I don't know what rpm a golf cart morot would turn.