Builders' Forum Archives
Posted by Camper on Jun 6, 2006
Agree with Charlie that 4hp (3000 W) is way overkill. I'm not even sure 1.5 hp (1100 W) isn't overkill.
If you DO go electric, why not try these two strategies to reduce the weight: first, get an electric motor with the same power as the main motor (that would be you). That would be closer to 200 W! (about 1/4 HP). (I'm assuming a prop has about the same efficiency as a paddle.)
Second, use Li or LiPoly batteries instead of heavier ones. They weigh one quarter as much as lead acid! 120 W-hr of LiPoly batteries (that means run at 120 W for one hour, in theory, less in practice) is only 1 kg. You could lose that weight in a week by eliminating cream cheese from your bagels.
This is if money is no object. If money IS an object, then you could go with NiMH batteries (like your Toyota Prius). They weigh less than half of lead-acid.
In Response to: motors by Taylor vanderbilt on Jun 4, 2006