alt.engineering.electrical

"bobelon" wrote in message
news:7a8960c7-f68e-46b0-adc0-df58143249d1@s37g2000prg.googlegroups.com...
On Feb 9, 10:00 am, "Tim Perry" wrote:
> wrote in message
>
> news:83cd63de-9ffb-45af-9baf-636bb2d873e6@e25g2000prg.googlegroups.com...
>
> > I am fitting an electric windlass on my Prout catamaran. I have
> > located a battery forward to be close to the windlass. The system is
> > a house bank and a starter battery separated by a battery isolator.
> > Power being supplied by the engine [30amp] alternator as well as 150
> > watts of solar. My plan is to use #8 awg wire from the battery
> > isolator starter battery terminal to the remote windlass battery (25
> > ft. away) and #6 awg for the short run from the battery to the
> > windlass (1000watts). I just realized that this may be a problem
> > because the starter and windlass batteries will try to equalize and
> > the #8 wire may not be of sufficient size. How do I deal with this
> > possible problem if there is one?
>
> If wired correctly a DBI (dual battery isolater) will prevent the
batteries
> from 'trying to equalize'.
>
> A DBI unit is pretty rugged but like anything man makes it can sometimes
> fail. Add a fuse or resetable breaker near the battery terminal. This will
> provide some protection in case the wires get accidently pinched or
shorted.

As set up the DBI splits the charge to the house bank on one side and
the starter battery and windlass battery on the other side. The
possible problem is these two are located 25 feet apart and connected
by an 8awg wire.

Another reason for thicker wire is termianl corrosion. Bigger wires just
last longer in harsh conditions.

Assuming a solar panal that 'trickle charges' the battery at an amp or so
under bright sunlight I wouldnt think a large wire is indicated for that...
however: the sad fact is batterys go bad, often enough when you least want
them to be bad.
I guess the windlass has an "armstrong' backup system but being able to
quickly jump batterys is a big plus in my book. you may even want to use
that battery to start the engine sometime.

Are you familier with the 4 position dual battery switch? if not search for
'marine battery switch'.