[C320-list] Charger/Battery Wiring

[Bruce Heyman]

Bert,
Based on your description you have two banks of batteries, 1 and 2.  When
you have your Off, 1, 2, both switch in the both position it is making your
two batteries into one bank.

Generally when you are running your motor you want to switch them to both so
that they both get charged.  When you are sailing or on the hook you want to
switch to 1 or 2.  That way if you accidentally run the battery down too far
you will have the other one in reserve to allow you to start the engine.

There are ways to have it charge both batteries regardless of the switch
position.  Also many 320's have been owner upgraded by adding a starting
battery and then convert the two 12v batteries into a single bank (like what
you read in Calder where both positives and negatives are connected).  

On Somerset we have the two house batteries tied together into a single bank
and then a 12 volt starting battery that is in a separate circuit but
charged from the main bank via an echo charger.  

You are right that putting the two batteries in parallel (two positives
connected and two negatives connected) you maintain 12 volts but double the
amp hour capacity.  Another option is to go with two "golf cart" 6 volt
batteries but connect them in series.  Circuit to negative 1, positive 1 to
negative 2 and positive 2 to circuit.

There are lots of options and quite a few choices available.  The book you
are reading is IMHO the bible when it comes to boat energy and energy
management.
Bruce
Somerset 671 SoCal

-----Original Message-----
From: c320-list-bounces at catalina320.com
[mailto:c320-list-bounces at catalina320.com] On Behalf Of BAdams3491 at aol.com
Sent: Monday, October 23, 2006 6:38 PM
To: C320-List at catalina320.com
Subject: [C320-list] Charger/Battery Wiring

My charger died and I am in the process of figuring out how to wire the new

one when it arrives.  According to Nigel Calder's book, our batteries,
wired 
in parallel, should have the negative posts wired to each other and the  
positive posts wired to each other...thus keeping 12 volts, but doubling the
amps. 
 On my boat, the negatives are wired that way, but the positives are  not 
connected.
 
I sail on a lake, and spend lots of nights on the boat, but always with  
shore power.  When I'm away from the boat shore power is also always  on.
The 
battery selector is always selected to:  "Both On."
 
Since each battery has a positive wire to the four way battery  selector 
switch, does that negate the requirement to have the two batteries  wired
together 
by the positive terminals to be in parallel?   Or,  maybe my battery is not 
correctly wired to be in  parallel?   
 
Any suggestions would be welcomed.
 
Thanks,
 
Bert
At Ease
#442