Charging wire from alternator

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gwp

In my original wiring there isn't a smaller (maybe#10) wire ran from the distributor to the battery for charging? How does the engine charge batteries without a dedicated wire? Does it somehow charge they the big primary starting cable? Any help appreciated

KWKloeber

What engine/year?
Has any major reworking been done?
Does your cockpit panel have a voltmeter or an ammeter?
Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.
So throw off the bowlines.  Sail away from the safe harbor.  Catch the tradewinds in your sails.
Explore.  Dream.  Discover.   -Mark Twain

gwp

1988 C34 25xp
Have only volt meter on electrical panel and no re-wiring I'm aware of.  I just read an old post on some other forum possibly answering my question. They indicated there is not a separate wire used to charge batteries while engine running.... The charging current runs back thru the primary big battery cable. Is this accurate? The C34 wiring diagram in the manual does not show another separate wire for charging. Thanks for quick response!

Stu Jackson

Stu Jackson, C34 IA Secretary, #224 1986, "Aquavite"  Cowichan Bay, BC  Maple Bay Marina  SR/FK, M25, Rocna 10 (22#) (NZ model)

"There is no problem so great that it can't be solved."

mainesail

Quote from: gwp on July 11, 2020, 02:51:07 PM
In my original wiring there isn't a smaller (maybe#10) wire ran from the distributor to the battery for charging? How does the engine charge batteries without a dedicated wire? Does it somehow charge they the big primary starting cable? Any help appreciated

Can you explain what you mean by the word "distributor"? A distributor would typically be on a gas engine. What does this "distributor" look like? Can you provide a photo?
-Maine Sail
Casco Bay, ME
Boat - CS-36T

https://marinehowto.com/

gwp

So sorry. Don't know where distributor came from. I meant alternator. This is what I want to do and surprised I can't find more info on web. I have 2 AGM battery bank and I am installing 2 - 100w solar panels with mppt controller. I simply want to add a starting battery and isolate it from any current draw but want all 3 batteries to charge from all sources...engine, solar panels (and 2 bank battery charger from shorepower). All wiring is pretty much stock. My plan is to redirect the starting cable from engine to the new starting battery. Since last post I've learned about an Automatic Charging Rely (ACR) which should eliminate any house-draw on starting battery but allow charging current. Am I on the right track? Thanks much

Stu Jackson

Quote from: gwp on July 12, 2020, 05:10:24 PM
So sorry. Don't know where distributor came from. I meant alternator. This is what I want to do and surprised I can't find more info on web. I have 2 AGM battery bank and I am installing 2 - 100w solar panels with mppt controller. I simply want to add a starting battery and isolate it from any current draw but want all 3 batteries to charge from all sources...engine, solar panels (and 2 bank battery charger from shorepower). All wiring is pretty much stock. My plan is to redirect the starting cable from engine to the new starting battery. Since last post I've learned about an Automatic Charging Rely (ACR) which should eliminate any house-draw on starting battery but allow charging current. Am I on the right track? Thanks much

and surprised I can't find more info on web

Please go to the 101 Topics sticky on this very C34 forum, and scroll down to Electrical Systems 101, which I have complied over the years to answer the very questions you are asking.  They also have links to Maine Sail's excellent website, which is right in his signature.

My plan is to redirect the starting cable from engine to the new starting battery.

You don't want to do that.  You want and need all charging going to your house bank.  ACRs or switching can be used to charge your start battery.  Those wiring diagrams are included in the Elec Sys 101 topic and Maine Sail's (many are his own diagrams), under Basic Wiring Diagrams, which include detail text explaining the hows and whys.

Am I on the right track?

Asking here means you are!   :D    We have developed and saved all this information so you don't have to reinvent the wheel.

Keep on coming back with any and more questions, we're here to help.
Stu Jackson, C34 IA Secretary, #224 1986, "Aquavite"  Cowichan Bay, BC  Maple Bay Marina  SR/FK, M25, Rocna 10 (22#) (NZ model)

"There is no problem so great that it can't be solved."

KWKloeber

GWP

Since you indicate there were no major witing changes, your charging most likely is the original setup.
Since you have a voltmeter on the panel, the alt output jumps directly over to the large "B (battery) terminal" on the starter solenoid.  The same terminal post that the positive battery cable is on.

You can charge all sources, but there are different ways to do it.  Carefully look at the info Stu pointed you to. 
Some just prefer to charge sources manually with a KISS system (hands on method) -- switch over to what you want to charge.  Others want to do it automatically with a more elaborate system (hands off method.)

it begs the question of what you mean by a "starting" battery. 
Are you planning to use it to start (every time)?
Or use it as a reserve (emergency) start battery? 
(My opinion is) for most people and the way they use their boats, there is little reason to have a dedicated "starting" battery but good reasons to have a dedicated "reserve" battery.

What are you trying to accomplish or "fix" with the changes you want?
Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.
So throw off the bowlines.  Sail away from the safe harbor.  Catch the tradewinds in your sails.
Explore.  Dream.  Discover.   -Mark Twain

gwp

Thank you for the responses. With the new electron demands of refrigeration I want to ensure under any circumstances I can start engine. In my thinking, the answer is a battery solely dedicated to starting engine. As I indicated in earlier posts, I am installing two 100 watt solar panels hoping that my two group 31 deep cycle batteries will do the job. Without getting too deep and analytical, what is the simplest way to accomplish this? I understand I can go manual thru switches but think I'd rather use a device to avoid relying on my failing memory like the ACR relay. I guess if rather explain to my wife went the fridge is warming rather than why the engine won't start. Thanks again

Noah

#9
Many of us have gone to larger house battery banks (four 6v) plus some have a reserve/start battery as well. I have 4 Trojan T105s (6v) plus a (12v) start/reserve battery, which is charged from the main bank with a Xantrex Echo Charger. The start/reserve battery (sealed flooded group 24) has a separate on/off switch, as well as a switch enabling me to combine it with house bank in an emergency. Lots of ways to skin this cat. My schematic and many others are on this website. With LOTS of other discussions about wiring upgrades.
https://c34.org/bbs/index.php/topic,4546.msg56771.html#msg56771
1990 hull #1014, San Diego, CA,  Fin Keel,
Standard Rig

Stu Jackson

Quote from: gwp on July 13, 2020, 06:10:33 PM
Thank you for the responses. With the new electron demands of refrigeration I want to ensure under any circumstances I can start engine. In my thinking, the answer is a battery solely dedicated to starting engine. As I indicated in earlier posts, I am installing two 100 watt solar panels hoping that my two group 31 deep cycle batteries will do the job. Without getting too deep and analytical, what is the simplest way to accomplish this? I understand I can go manual thru switches but think I'd rather use a device to avoid relying on my failing memory like the ACR relay. I guess if rather explain to my wife went the fridge is warming rather than why the engine won't start. Thanks again

You may find many answers to your questions in the 101 Topics:

Electrical Systems 101   http://c34.org/bbs/index.php/topic,5977.0.html

It's a sticky on this forum.
Stu Jackson, C34 IA Secretary, #224 1986, "Aquavite"  Cowichan Bay, BC  Maple Bay Marina  SR/FK, M25, Rocna 10 (22#) (NZ model)

"There is no problem so great that it can't be solved."

KWKloeber

gwp

Since I have a KISS system, I rely on a dedicated RESERVE battery, not a start battery.  I always start from the house bank, which means to start I change nothing.  To charge, I change nothing.  I don't need to do anything and remember anything, don't need to move the selector switch -- just start every time the same way.  The engine immediately replaces what I used to start, and I always have a reserve (read: an emergency battery -- there for just what it says.)  Should the house ever be too low to start 'er I have a full battery there.  Think of it as a plane's reserve fuel tank, it isn't used unless it's an emergency.

Most folks think that they are "wasting" a huge hunk of their house energy by always starting from the house bank, but it ain't so -- starting our little diesels uses about 1/10 amp-hour.

I'm not saying that this is the best for your solution, I'm just saying that is a very KISS solution for VERY LITTLE money and many don't even think of it since a more-complicated, a more costly, "automatic" must be better just because they're better.  But sometimes (I'd say >50%) it isn't needed - particularly so if she's tied to a charger every night -- then there is VERY little need for anything except the stock charge setup that tops off every PM.  More complicated solutions aren't always needed "just because."  Sometimes it's better to put limited boat bucks into charging (more efficient) system improvements, than into unnecessary hardware.

Just my 0.02 (or 0.027 CDN.)
Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.
So throw off the bowlines.  Sail away from the safe harbor.  Catch the tradewinds in your sails.
Explore.  Dream.  Discover.   -Mark Twain

mainesail

Quote from: gwp on July 13, 2020, 06:10:33 PM
Thank you for the responses. With the new electron demands of refrigeration I want to ensure under any circumstances I can start engine. In my thinking, the answer is a battery solely dedicated to starting engine. As I indicated in earlier posts, I am installing two 100 watt solar panels hoping that my two group 31 deep cycle batteries will do the job. Without getting too deep and analytical, what is the simplest way to accomplish this? I understand I can go manual thru switches but think I'd rather use a device to avoid relying on my failing memory like the ACR relay. I guess if rather explain to my wife went the fridge is warming rather than why the engine won't start. Thanks again

An ACR can be used with the OE 1/2/B switch. This article shows multiple different upgrade steps you can take to make the 1/2/B work better for you.

https://marinehowto.com/1-2-both-battery-switch-considerations/

-Maine Sail
Casco Bay, ME
Boat - CS-36T

https://marinehowto.com/

Stu Jackson

OK, I'll beat this dead horse one more time:

Both Ken and Maine Sail are repeating what is already in the Electrical Systems 101 topic.

Ken reprised one of the summaries of an option that's already there.

Maine Sail provided a link to his excellent website that's already there.

Give it a try!  :D

Perhaps it's just the nature of internet forums...
Stu Jackson, C34 IA Secretary, #224 1986, "Aquavite"  Cowichan Bay, BC  Maple Bay Marina  SR/FK, M25, Rocna 10 (22#) (NZ model)

"There is no problem so great that it can't be solved."

gwp

Ended up going with the KISS system and switch manually rather than the ACR relay. Thank you for all the advice. One thing which has me confused tho.... The primary negative cable.... Apparently.... goes directly from the engine block to the batteries and NOT thru the electrical panel area. However, when I remove the ground cable from the battery terminal I still have a ground coming from somewhere because the house circuits still power lights fans, etc. This has me bumfuzzled. I checked the manual wiring diagram and it doesn't show another groung going anywhere else? What's going on here?  Thanks again