T-Pain Is On A Boat: Re: [Electric Boats] Seeking opinions about this motor as a potential for a 30' Sailboat

Thursday, September 3, 2009

Re: [Electric Boats] Seeking opinions about this motor as a potential for a 30' Sailboat

Chip,

If that motor really draws 45 amps at no load it is horribly inefficient. Maybe you meant 4.5 amps?

At full load input power is 140 amps * 24v = 3360 watts = 4.5 hp; 4/4.5 = 88% efficiency. That's really high. Something is fishy.

140 amps CONTINUOUS (be careful how things are rated - "continuous" is all that matters in a boat) is a lot for a controller and a huge drain on the size of a lead acid battery bank that you would want to carry on a 30' sailboat.

Better to start with first principles: How fast do you need to go and how far at full speed? How far at half speed? How much battery weight can you accommodate?

Generally a 48volt system is more practical in the 4 - 6 hp power.

Denny
www.wolfEboats.com

----- Original Message -----
From: Chip G
To: electricboats@yahoogroups.com
Sent: Wednesday, September 02, 2009 8:38 PM
Subject: [Electric Boats] Seeking opinions about this motor as a potential for a 30' Sailboat

Love to hear the thoughts from the group about these specs as a potential motor for a 30' sailboat.

4 HP 24 VDC ELECTRIC MOTOR
45 AMPS NO LOAD
140 AMPS FULL LOAD
8000 RPM FULL LOAD
32 INCH POUND OF TORQUE
¾" DIAM. X 1 ¾" SHAFT WITH KEYWAY
MOTOR DIMENSION 4" DIAM. X 7 ¾"

My current gas burner shows 3000 RPM as highest rating on the diagram so I am thinking potentially about a 2.6:1 V-Belt configuration driving the shaft via a pulley on each end if I wind up going with this configuration. Your thoughts?

I sure like the approach that Arby has taken with the AMeP too and am seriously considering that path as well. Love to hear thoughts on this approach as well.

Thanks!
Chip

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