Date:         Sun, 5 Sep 2004 23:24:39 -0700
Reply-To:     Rocket J Squirrel <j.michael.elliott@ADELPHIA.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Rocket J Squirrel <j.michael.elliott@ADELPHIA.NET>
Subject:      Re: [Syncro] dual battery isolator
Comments: To: mark drillock <drillock@EARTHLINK.NET>
In-Reply-To:  <412B741E.9090904@earthlink.net>
Content-Type: text/plain; charset=us-ascii; format=flowed

Is there a schematic of how Sean probably has his aux battery setup wired?

I've also heard there is a nifty way to connect the relay to the
alternator idiot lamp so the relay kicks in when the lamp dims. But it's
not clear to me how to do this -- doesn't the lamp light when the
battery voltage is lower than the alternator output? Where would the
relay be connected in this case?

After discharging the main battery on my last camping trip I've ordered
an Optima and the hefty Stancor relay.
--

Mike "Rocket J Squirrel" Elliott
71 VW Type 2 / 84 Westy: A poor but proud race.
KG6RCR



mark drillock wrote:

> If you read your link, Sean used a RELAY instead of an isolator with his
> Optima dual battery setup. He also added an inverter. He first tried the
> wimpy relay kit sold by TBD but switched to a REAL relay that costs
> about $20 and can handle 100 amps.
>
> http://www.vgonman.com/auxbat.htm
>
> Mark
>
> randy charrette wrote:
>
>> I'm no electronics expert, so I found a web site (www.vgonman.com)
>> and copied his set-up. It has worked great for about 3 years now.
>> This is set-up with a isolater.
>> Randy
>> 87'Syncro TIICO
>>
>> David Marshall <VANAGON@VOLKSWAGEN.ORG> wrote:
>>
>> I can't see an issue with a 70A relay load wise as your alternator is
>> 90A
>> and only on a good day. I use a generic Bosch 40A relay for my 2nd
>> battery
>> in my TriStar and I have never had an issue and I have a 120A
>> alternator.
>> Charging battery from a dead flat doesn't make the relay nor the
>> 2x12ga wire
>> running to the battery hot or even warm to the touch. I think the
>> relay is
>> the simplest and probably the most effective of designs. The diode
>> isolators are not good in my opinion as they introduce a 0.7V loss in
>> the
>> system over both batteries. The computerized isolators that give the
>> starting battery and deep cycle the voltage they want to see is the best
>> bet, but expensive and really I think the deep cycle will charge fine
>> on the
>> relay with an alternator designed to charge a starting battery. 1000s of
>> fishermen driving home charging their deep cycles on their F150 can't be
>> that wrong.
>>
>>
>