In article , Chuck Cox
wrote:

purple_stars wrote:

if you want to use a fuel based system you've always had to step up
to suddenly wasting incredible amounts of fuel to run an alternator
that is very inefficient at charging batteries for the amount of fuel
wasted doing it, and there's not been a generator that is down in the
"few hundred watt" range that would make better use of fuel. battery
banks can only accept a certain amount of power, and a 5000 watt
generator might as well be a 500 watt generator because you can't
charge the batteries any faster than using a few hundred watts anyway,
so you're just wasting energy for nothing. nobody has ever bothered to
make and sell an inexpensive small diesel generator designed to charge
a battery bank, at least not that i've ever seen. cruisers are
interested in the measurement "battery bank watt hours created per
liter of fuel", and i'm not aware of any manufacturer that has ever
thought about it that way. most generator makers just think of "watts
generated per liter", which isn't the same thing at all.

That is exactly our thinking too. By optimizing the system for charging
only, we can maximize efficiency. Our biggest advantage is that we have
a fixed load and can optimize the system for a very narrow operating
range in terms of speed and power. Although we are using an
off-the-shelf motor, we expect to use custom induction & exhaust systems
in order to maximize efficiency and minimize noise and size.

i would think that hooking it into the fuel line for the engine's fuel
tank would be the preferred way, but why not make the external tank an
option ? that way you can decide for yourself when you buy one if you
want the tank or if you want a piece of fuel line and a T adapter.

As a small business, we can only afford to design, manufacture and
support one configuration initially. I'm trying to figure out which
configuration would be our best first shot.

diesel is definitely the way to go, storage of gasoline is a problem.
it would be nice if it used fuel filters that you can get at the same
time as the ones for your marine engine without special ordering.

Our intention is to use as many off-the-shelf components as possible.
However, most of the parts probably won't be found in a typical marine
catalog because I don't think there are too many 1 hp marine
diesel-electric applications.

I have a 3 HP manual/electric start air cooled Yanmar marine diesel
with integral tank & 2:1 F-N-R box I picked up som years ago waiting
for the right project. I actually had something like this, or using it
to drive a hydraulic pump, or both, in mind.

PDW