On Fri, 12 Nov 2010 06:57:42 +0100, "Steve Lusardi"
wrote:

I think you are on the right track but those kind of currents indicate your ship voltage should be 24 volts not 12. I really like
your golf battery solution. I hope your inverter is sinusoidal and not square wave, as the latter will play havoc with most
electronics not to mention its RF generation. Just as a note, some of the popular computer UPS systems use 24V internal batteries.
They are easy to modify for external power and they produce a clean sinusoidal output.

Yes, the inverter is sine wave output, and we have a smaller one for
backup. I previously installled a modified sine wave inverter on our
old boat and we had a number of issues with it. There's no longer a
reason to go non-sine wave in my opinion since prices keep dropping on
the electronics.

I also agree that 24 volts would be desirable but that would have
required a lot of modifications or setting up some sort of dual
voltage system since everything on the boat is set up for 12 volts.
It is much simpler having everything at one voltage even if not
entirely optimal. I even considered a 48 volt inverter at one point
with a totally isolated house bank to feed it.

As it is the golf cart batts are less than 4 feet from the inverter
and alternator, and everything is interconnected with 2/0 and 4/0
cables which minimizes IR losses.