Date:         Wed, 25 Feb 2004 07:09:12 -0800
Reply-To:     mark drillock <drillock@EARTHLINK.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         mark drillock <drillock@EARTHLINK.NET>
Subject:      Re: 2nd battery ??
Comments: To: Dan <william.winget@VERIZON.NET>
Content-Type: text/plain; charset=us-ascii

Using the Westy fridge relay to provide the power source to charge the
second battery is not a great idea. The long wires involved as well as
the many connections, can result in a low voltage that won't fully
charge the second battery. BTDT

The Westy fridge relay and the rare factory second battery relay are NOT
turned on by turning the key to the on position. The relays are
connected to the alternator charging indicator circuit and only turn on
when it appears that the alternator is charging.

The best way to connect a second battery is connect the 2 batteries
together with heavy gauge battery wire of as short a run as feasible.
Put a heavy duty switch or relay in between the batteries. You can mount
the relay under the driver's seat along with the second battery and use
the Westy fridge relay to control the battery relay.

SurePower makes a special relay device that may be the simplest and most
straight forward way to wire in a second battery for a Vanagon.

http://www.surepower.com/Products/batsep.asp

SurePower also makes a battery isolator device that is not well suited
to the Vanagon applications as the alternator must be modified as well
as the main vehicle charging wiring harness. With the separator product
you don't need to cut or splice or modify any of the stock wiring in
order to add a second battery.

I recently purchased the Sure Power Model 1315 Separator to use in my
remote vacation shack that has solar panels and battery banks as the
only power source. It cost $70 and has several features that make it
ideal for Westy use. It has capabilities that are impossible with an
isolator.

The above opinions are from my experiences with adding second batteries
to a dozen or more VW Vans. I have used isolators, switches, and relays
at various times. I think relays are the better way to go for most
owners.

Mark


Dan wrote:
>
> I am going to install a yellow top deep cycle optama.  I have 2 questions
>
> 1)  Can I use my exsisting fridge relay to hook up the 2nd battery ??
>
> 2)  if the relay is energized by turning the key to the on position,  what
> prevents power being drawn from the 2nd barrery and burning out the rellay
> and charging wiring
>
> Thanks
>
> Dan