[C320-list] Battery Isolation

[warren updike]

Julian, I used a CL-Series Battery Link 7600 from Blue Sea Systems and am
happy with it. The only other unit I considered is one that has a 3-stage
charging program. However, I find it's not really necessary as the starting
battery is never much discharged and so is almost always at absorbsion for
float stage and is never poses much of a demand on the charging system.

I do highly recommend that in isolating your starting bank that you replace
the 1-2-OFF-ALL switch with a Blue Sea e-series switch. It's an easy change
as all the wires are right there. This switch is either on or off, and
switches the house and starting banks separately. The benefits of this may
not be readily apparent; but, it removes any consideration of where the
alternator charge is going. 

In doing this, you need to consider re-wiring the output positive from the
alternator. As delivered, the alternator charge goes to the pos. wire on the
starter. When you separate the starting and house banks you want the
alternator charge to go to the house bank and let the relay manage the
starting bank.  The best way to do this is to run a new pos. from the
alternator to the house bank with no intervening connections. I cheated and
ran the new wire to the house bank side of the e-series switch. That way,
the alt. charge goes directly to the house bank. The down side is that there
is one connection in the run. The up side is I didn't have to fish a wire
under the port water tank back to the battery bank.

Send me a message off-list if you want to see a wiring diagram for this
approach.

Warren & Pattie Updike
Catalina 320, #62, "Warr De Mar"
Middle River, Chesapeake Bay

-----Original Message-----
From: jelliott at landspring.net [mailto:jelliott at landspring.net] 
Sent: Wednesday, April 08, 2009 10:59 AM
To: C320-List at catalina320.com
Subject: [C320-list] Battery Isolation

I am in the process of modifying my electrical system, and am curious as
to how others electrically isolate the house bank from the starting
battery.

I have two 4D's under the settee paralleled as my house bank, and a
separate  starting battery located in the port lazarrette.  Both are
connected to independent channels of a Xantrax Truecharge 20.   The house
bank is monitored with a Link 10.

The banks are still not electrically isolated; I assume this is a result
of a common connection to the alternator?  How do others handled this?  I
understand there are battery isolators that do this?  Any advice on how to
"break" this return circuit (if that's the cause) would be appreciated.  I
am not very interested in adding a second switch which I know some have
done.

Thanks,

Julian
Polaris #340