Alternator/ Battery Questions

[ansusna]

I am trying to get my head around our DC power system.  This summer our batteries seemed to be having trouble staring the engine.  The problem seemed worst when the relying on the alternator to charge the batteries.   We had the battery tested and the result was that the battery charge was good, but the CCA capacity was down to less than 60% the rated value.  This was consistent with an "Sluggish Starting" article in the Tech Notes. I replaced both Group 27 Batteries with Group 31 batteries that have a little more capacity and CCA.  We only have one battery bank.

Since Hurricane Isabel we have not had shore power on our dock.  By the way, we are on "G" dock at Herrignton Harbour North and came through fine (luckily!).  Anyway, I have had to charge the batteries solely with the alternator.  I did not check the original charge, after 2 1/2 hours of charging with the alternator the battery voltage was up to 12.45 Volts.  This represents roughly a 75% charge.  I charged the batteries again today for 1 1/2 hours.  The alternator voltage started at 13.4 voltage and dropped to 13.35 (measured across the battery terminal)  The alternator is the original "Low" output alternator.  

My question is two fold. (1) based on this information can I conclude that the alternator is shot? (2) is the original alternator internally regulated to output at 14.4 V for a wet-cell battery?

[Ted Pounds]

Andrew,

Have you done the wiring harness upgrade?  With the old setup you can have a half volt or so drop from alternator to battery.  That can have a huge effect on charging.  Just a thought...

Ted

[rwilkinsii]

How do i find out if my wiring has been upgraded and if not where id i get it from?

Thanks

Rich Wilkins
Houston Tx
86 c34
S/V Lil Tiger
Geaux Tigers!!

[burner]

Ok, at the risk of suffering severe wrath for not being able to find the info for upgrading the wiring harness, I've looked and been unable to find anything specific about the procedure.  I have found much written about the fact that it needs to be done, and I also found one place that said that Seaward Products has the kit.  However, I haven't been able to find the kit on Seaward's website.  I've looked through the Tech Notes and haven't been able to find it.  Not that it isn't there, I just can't seem to find it.....

[Stu Jackson]

WIRING HARNESS REFERENCE

Here it is:

http://c34.infopop.cc/6/ubb.x?a=tpc&s=329609511&f=829605811&m=808601781&r=101604781#101604781

The best $50 you can spend on your boat is Nigel Calder's Boatowner's Manual.  In lieu of us "re-writing" books that have already been written, and explaining complicated electrical boat systems, why not try it out?  You could either try a library, sit down in a marine store for an hour, or buy the book.  Also, Santa's on his way!

Stu

[burner]

Thanks for the info and link.  I will definitely look for the book.  I think it will help tremendously, even though I have been working with DC electricity all my life, first as a technician, then as an engineer, finally as a manager - (translates to being able to surf the Catalina website and get paid to do so).  I've ordered the harness kit for the boat, soon to upgrade.....

[rwilkinsii]

I called seawardprodcuts and i had it ordered with-in 5 min.. they are very helpfull and knowledgable.

Rich Wilkins
Houston Tx
86 c34
S/V Lil Tiger
Geaux Tigers!!

[burner]

Agree with you about calling them rather than using their web.  Talking with them was worth the effort.  Very helpful, asking me questions making sure they were getting me the right thing.  Like Rich said, five minutes later it was ordered and I was finished.

[ansusna]

Ron,

Thanks for the advice.  I'm working on the alternator upgrade.  In addition, your right about the wiring harness upgrade already being completed.  The instrument panel has a voltmeter that reads approximately the same voltage as the measured across the batteries.

Thanks!

Andrew

Andrew