[Public-List] Alternators

[Stephen Gwyn]

A few points:

1) Don't get a clamp on ammeter to measure power. They aren't very accurate
a low level DC currents. And they are expensive. Do get a instrument panel
mounted ammeter. I just got one for 35$.

2) If you can't find the RPM-> Amps curve for your alternator, take to an
alternator shop. They can put it on a machine and tell you. They can also
change your pulley for a smaller one which will give you more amps per
engine RPM. If you do that however, you will almost certainly need a
different alternator belt.

3) The excitor doesn't need high RPMs to work. It gets it's power from the
batteries. But alternators do usually have a steep power curve at low RPMs.

4) Your sailing style heavily affects what kind of alternator you need.
Normally, I motor maybe an hour a day (half an hour to get in and out of
harbour) once a week. That also carries over into normal cruising, where I
spend a lot more time sailing (or at anchor) than motoring. This summer,
I'm up windless inlets and fjords a lot more, so if anything my batteries
are over charged.

SG