New electrical system

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C

Chief

I am starting to plan out my winter projects, and one that I never completed was the installation of my new alternator and external regulator. I had gotten cold feet on the installation when I found that a PO had made some modifications that did not make sense. I had decided to let my yard complete the work, but after two weeks of the boat just sitting, I decided since it was just PM (replacing the alternator) I would take the boat. I figured if I was able to find a mechanic during the summer willing to do the work, then I would have the alternator and regulator replaced. No luck, so now I have the same problem again. This time the yard has the whole winter to get the job done. I had some battery issues this season,and never quite figured out what was going on. I think it is time to replace everything except my shore charger. The boat is an 89 Cat 30, with an M25XP engine. I currently have two Group 27 AGM batteries. I would like to add a dedicated starting battery and upgrade everything to have dependable starting and enough power to keep my instruments and stereo going. I do mostly day trips with the occasional overnight. I am in a slip so shore power is always available. I am going to finally have the new alternator installled along with the new external regulator. What else would beside new wires would bring everything up to modern standards? I read about battery isolators,combiners, Link monitors etc. I do not want to spend a fortune, but want it right.
 
C

Charles

solar power

For power on my 25 i built a stainless steel tower off the back that holds 2- 50 watt solar panels. They are connected to a charge controller. I have two battery banks. Number 1 bank is a #27 wet cell used for starting the motor. Number 2 bank is two # 27 wet cells. I used to use AGMs, however, when they go bad they go bad without warning. Both banks are connected to a battery swith. I cruise a few times a year where i anchor out for 2 to 3 weeks. I always have enough power for lights, radios, autohelm,tv and an Engel refrigerator. The motor keeps the start battery full and the solar panels are directely connected to the house bank.
 

GuyT

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May 8, 2007
406
Hunter 34 South Amboy, NJ
Battery answers

Chief, if you search the archives you will find many answers to your questions. Battery chemistry is a matter of economics - wet is the least expensive but the most maintenance. GEL and AGM are maintenance free, GEL is better at temperature and cycling. Stick with the same chemistry between house and starter banks. Get a dual charger so both banks can be charged when plugged in. Make sure you use marine wire - it is tinned and resists corrosion much better. The link system is very good but has its issues - this is also searchable in the archives. It is not too easy to install - it may take a full day. It is definately not an hour job on a sailboat where the batteries are usually down a lazarette and in confined spaces. There is a dual shunt for current sensing to install near the batteries on the negative leg and then there are sensing wires to run to the main unit for sensing the battery voltage and current. You need to follow wirring diagrams but it is pretty straight forward. Ultimately the best weapon you can have against your battery is awareness and knowledge. Get a book - there are countless references to Nigel Calder. The money you spend educating yourself about batteries and battery systems is the best money spent IMHO.
 
Feb 26, 2004
23,344
Catalina 34 224 Maple Bay, BC, Canada
Here's a place to start

http://www.c34.org/projects/projects-electrical-system-upgrade-2.html Also consider this: Alternator Output: The older boats with only one 1-2-B switches are usually factory wired with the alternator output to the “C” post of the switch. This means that the switch was actually used for two purposes: (1) which battery bank(s) the alternator charge goes to when the engine is running; (2) which bank is chosen for use for DC power. We changed that. We moved the original alternator output FROM the “C” TO the “2” post (our house bank) of the switch. The Combiner charges the start bank without having to use the 1-2-B switch for selecting alternator charging output ONLY because we moved that connection. The revised alternator charging path was from the alternator through the AutoMac to the “2” switch post to the house bank, using the #4 OEM red wiring. IMPORTANT NOTE: You cannot simply move the alternator output from the “C” to the “2” post without a Combiner or Echo Charger type relay equipment because the start bank would not get charged. Another way to put this is: If your alternator output is wired to the C post of the 1-2-B switch, and you do not have a combiner (or equivalent), then you have to start the engine with the switch on B (ALL) because this would be the only way to charge both of your banks from the alternator." What this means is that most boats have the output of the alternator going to the 1-2-B switch, which I don't feel is "proper" because it uses the smaller battery "output" wiring from the batteries TO the switch which only need to carry 15 to 20 amps while alternators are usually putting out more amperage. I suggest this should be changed in any new system. Look at www.amplepower.com and download their Ample Power Primer. YOU have to design the system you want after understanding how it is supposed to work. There is NO ONE "right way" to do it. For instance, West Marine Advisors (also a good source of great information, read their catalogs or online) suggest three switches. I opted to continue to use our 1-2-B switch for battery OUTPUT to the starter and DC panel with the charging sources going directly to the house bank and a combiner to the start bank. Many others have used different switching or relay methods to charge their start banks. It's all up to what you want to do. Time for Homework and Research. :)
 
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