[C38] Alternators

Wed Sep 14 20:24:55 EDT 2011

Hello Larry and group,

I'm slightly off guard since I have not researched this topic lately but, Like Michael Cameron said, sometimes a larger alternator can bring on other problems that you may not want to have to deal with.  I don't know what engine you have but there have been many failures with the larger alternators on the Universal 5424 series because of the extra mechanical load to the mounting brackets, water pump and pulleys.  Making that @#$%^ water pump last as long as possible is a really good thing!

A really large battery bank will put an extreme load on the original alternators but they should be up to the task, even if they take longer to top off the batteries.  Keeping the alternator cool is another way to make it charge better and last longer.  I have a ski boat in our family with a directed air supply to that alternator since the engine compartment is so hot.  Our Catalina engine compartments can be quite hot also.

When I took a 500 mile cruise from Tampa Bay to Key West and back, we ran our engine about 20 min. at sunset every night to top off the charge and heat the hot water heater for showers.  Other than that, we ran a solar panel mounted on the stern pulpit with adjustable brackets to allow the panel to be perpendicular to the sun for maximum charging efficiency.  We also rigged a bungee cord on our steering to reduce effort on the AutoHelm steering.  That was the longest cruise we made but we never needed any more than our original alternator with the wiring and lighting efficiency upgrades we had made.  We used the microwave every meal and ran our well insulated refrigerator non-stop.  The steering ran from port to port, non stop.  Without the bungee, the steering servo would get really hot.  After balancing the helm with bungee cords, the motor stayed cool which means we saved a lot of battery power with that simple procedure.

Marine alternators have been certified for marine use which I think just means they can charge more money but I'm a perpetual skeptic so ignore me on that.  The Balmars have a powder coat paint job but surface corrosion on an alternator case is purely cosmetic.  I have no idea what the difference is other than paint or if the difference has anything to do with making marine certified alternators explosion proof.  I expect being spark and explosion proof would be a benefit to gasoline vessels but we run diesels.  I think it may just be a way to charge more money.  I have known many people who have used off the shelf automotive alternators with good results, including myself in previous boats.  I have also known people to have alternator rebuilding services to rewind their original alternators to make them more powerful but I have not heard of anyone doing that in a long time.   I am not sure they still do that procedure but a quick phone call to a rebuilder could answer that question.

With the high price of marine parts, I try whenever possible to use a quality automotive (or Kabota tractor) substitutes when safety or durability aren't compromised and in this case I honestly can't say without doing some research.  If I can learn anything, I will reply as soon as possible

By the way, before I upgraded the electrics on my boat I was seriously considering a larger output alternator like the Balmar and I'm glad I stayed with the original.  Is there anything left to do on your boat that would conserve more electricity? 

Tom Troncalli  

----- Original Message ----- 
From: Michael Cameron 
To: Larrypi at roadrunner.com;Catalina 38 Listserve
Sent: 9/14/2011 6:12:08 PM 
Subject: Re: [C38] Alternators

Larry,

 We have 2 8D AGM batteries in our boat plus a AGM start battery.  We do fine with a 100 amp Balmar and smart regulator . That is approximately 500 amp hours of batteries to charge, similar to your requirements.   We have cruised for 9 days at a time with no shore power and never been more than 125 amp hours down on the battery bank.  150 amp alternator is going to require double half inch belts or a wide single belt, which will mean new pulleys.  If I had an alternator that big I would want a by pass switch so that when I needed all my horsepower I could cut the alternator load out of the picture.

michael

From: Larry Malmberg <Larrypi at roadrunner.com>
To: Catalina 38 Listserve <listserve at catalina38.org>
Sent: Wed, September 14, 2011 2:41:09 PM
Subject: [C38] Alternators

OK, time for a new discussion here.  I have heard, read and been led to
believe that there is little difference between Balmar, others and
traditional alternators and voltage regulators.  I have been looking around
the net at alternators, external regulated, voltage regulators and such and
the more I look the more confused I get.  Tom T. are you out there???  My
Marine Electrician tells me I need a 150 amp alternator due to my batteries,
four 110 amp AGM's for house and one small start battery.  I currently have
a 90 amp alternator and a Balmar programmable voltage regulator.  Am I off
in the wind here or???

Best regards,

Larry Malmberg
Team Hassle

_______________________________________________
Listserve mailing list
Listserve at catalina38.org
http://catalina38.org/mailman/listinfo/listserve_catalina38.org
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://catalina38.org/pipermail/listserve_catalina38.org/attachments/20110914/667428a0/attachment-0001.htm>