SA Design


Eco Drive II

is an amazing thread about electric propulsion that we mentioned yesterday.
Trevor Baylis starts it off:

let’s try to work together and design this system that we all seem to

the goal:

A retractable propulsion system for a 10m/33′ race boat weighing about
2.5 tons. (Something like a Synergy-1000.)
Able to drive the boat @ about hull speed, even in a bit of chop for 10
hours. (The delivery from Santa Cruz to San Francisco.)
A charging system capable of running the ships’ systems for a 14 day ocean
race, including a bit of communications, computer, running lights, etc.
(Pacific Cup.)
It would be nice to be able to get in and out of the harbor without running
the motor, but this is not necessary.

Not too expensive, maybe under $7,500 including batteries.
As light as possible for the complete system.
Easy to use: Electric start, simple door system, simple retraction and
deployment system. It would be nice to be able to loan the boat out
to someone to use without having to spend hours explaining the system.
Retractable when the boat is moving @ 6 knots??? This may not be possible.


Right now the system that comes closest to this is an 10hp (~7.5kW, I
think) outboard in a well plus a Honda EU1000i generator in the aft locker
that’s pulled up on deck for charging when the solar can’t manage. This
all runs off of gasoline, which is fine by me, and weighs about 105 lb
(outboard) + 30 lb (generator) + 20 lb (solar panel) + 48 lb (6 gal. gas)
+ 110 lb (150 Ah of gel battery) = 313 pounds for going to Hawaii, maybe
105 +48 + 55 = 208 lb for a regular setup with some shore power.

you think we can work together and make a real system? Join
the band