BoatBanter.com - View Single Post - Electric motor to power a dinghy revisited

wrote:
.... Meaning the following flow of
energy: fuel - alternator - battery - motion with multiple
transition of energy back and forth from/to chemical (2 types),
electric (2 times), and motion (2 times) type forms. This cycle just
does not seem as efficient as a simple fuel - motion.

No, it isn't as efficient but it can have other benefits.
Simplicity, reliability, instant on, quiet... but you pay
for those.

.... Plus, the time
required to recharge---I don't think I'll have it. I'll start looking
for some 4-stroke outboard like Honda now.

cavelamb wrote:
The outboards on small day sailers seldom have alternators, which means
no way to charge batteries.

I know that with a 5hp Honda, a 4 amp alternator is an
option. We had one. But 4 amps is not very much power! It is
enough to power running lights and maybe recharge a small
battery over the course of a long day motoring.

Retail is often so frustrating...
Outboards are rated in horsepower. No thrust rating?
Trolling motors are rated in pounds thrust. No power rating?

You can convert both to watts if you like. it's not going to
be a head-to-head match up because the engines are measured
at very different RPMs.

I'm thinking a 60-100 pound thrust motor on a 1500 pound displacement hull
isn't going to win any drag races, but should (eventually?) move out.

Sure. I know of many people using trolling motors to move
small sailboats when the wind dies. Works like a champ. Of
course, you ain't gonna pull no water skier with a set-up
like that anyway.

Fresh Breezes- Doug King