David Marshall wrote:

> Mark and the list...
> I've been looking at this whole second battery isolator / relay thing.   I've seen some systems that want the tach or W
> terminal signal to trigger the relay or a manually operated relay.  What is
> wrong with a 'simple' $9.95 relay wired like this:
>
> 30      Alternator or 1st Battery Positive pole
> 85      0.3 BAR oil pressure switch
> 86      looped back to the 30 terminal
> 87      Positive terminal of the 2nd battery
>
David,
        The Sure Power Separator uses the voltage of the main battery to
trigger the relay. Once the main battery reaches 13.2-13.5 volts the
relay connects the aux battery to the charging current.

        Another function is to disconnect the main battery from the current
draw when it (main battery) drops below 12.4-12.9 volts.

        Optionally, if the main battery voltage is lower than the aux battery,
both batteries can be used to start the van.

        You pay more, but you get more.

My 2&162;
John Meeks
Vanagon Rescue Squad
http://www.vanagonauts.com/catid=74
91 MultiVan