Winhes can pull a ot of current and no alternator will support that for any
lenght of time. You really want to put the winch on the secondary battery
with as direct and large a connection as possible. Then the ultimate charge
control would be a combining, voltage controlled relay. The operation would
be as follows:

Enigne running, normal charging voltage will connect the 2 battery banks.

As the winch is used, when alternator fails to keep up, combiner will drop
out allwing alternaotr to restore mani battery and as mani battery voltage
increases relay will again close to transfer some power to the auxillary.
Yes, while winchng there will be some cycling going on.

This will avoid alternator burn out and dead battery. Auxillary/winching
battery or battery bank should be as large as affordable, fittable as you
can get.

Consider a fast idle control of some sort  to step up the rpm when needed.
If you have room you may want to consider one of the full size truck style
alternoators. I don't know what belt drive you have but if a single v-belt
that will also limit how large an alternator you can actually turn.

Dennis

>From: David Marshall <mailinglist@FASTFORWARD.CA>
>Reply-To: David Marshall <mailinglist@FASTFORWARD.CA>
>To: vanagon@GERRY.VANAGON.COM
>Subject: Re: 120A or 150A Alternator Source?
>Date: Mon, 29 Oct 2007 07:34:54 -0700
>
>This alternator is really for my LT 4x4 - which uses the same alternator
>as the Vanagon - save the pulley.  By the end of the week I will have
>dual winches on it and it also has the mega large battery in it which is
>the same size as the Touareg... a 2nd battery will be installed so I can
>jump start myself in case I run down the main battery when winching.
>Plus, I have 600W of high beams, heated seat and a bunch of other
>electrical accessories that make my system voltage drop to down to 12V
>when they are all running - at idle with no accessories running we are at
>13.8V - I figure with the alternator starting to squeak a little it's time
>to upgrade before disaster strikes.
>
>David Marshall
>
>http://www.hasenwerk.ca
>http://www.fastforward.ca
>
>Box
>4153, Quesnel BC, Canada V2J 3J2
>
>On Mon, October 29, 2007
>05:44, Dennis Haynes wrote:
> > Iraggi sells bolt on high amp
>alternators for the Vanagon. Do you really
> > need more alternator
>or better wiring. The wiring is not adequate for the
> > output
>already available. Keep in mind that most  high output alternaotrs
> > will put at less current at low-idle speeds.
> >
> >
>Dennis
> >
> >
> >>From: David Marshall
><mailinglist@FASTFORWARD.CA>
> >>Reply-To: David Marshall
><mailinglist@FASTFORWARD.CA>
> >>To:
>vanagon@GERRY.VANAGON.COM
> >>Subject: 120A or 150A Alternator
>Source?
> >>Date: Sun, 28 Oct 2007 21:26:44 -0700
> >>
> >>Is there a direct bolt on 120A or 150A alternator
>out there that will
> >>replace the 90A Vanagon alternator - or
>one that will work with a little
> >>bit of modification?
> >>
> >>David Marshall
> >>
> >>http://www.hasenwerk.ca
> >>http://www.fastforward.ca
> >>
> >>Box
> >>4153, Quesnel BC, Canada V2J 3J2
> >