Dumb Electrical System Question - SailNet Community
 3Likes
Reply
 
LinkBack Thread Tools
post #1 of 18 Old 12-03-2018 Thread Starter
Junior Member
 
Join Date: Dec 2018
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
Dumb Electrical System Question

A previous owner upgraded the electrical system on my sailboat. It has two - 4D size batteries for the house systems and a single starter battery for the engine. My understanding is that the starter battery is supposed to be isolated and completely dedicated to starting the engine. However, the other day, I had to remove one of the 4D batteries and found out that the engine would not turn over. When I hooked the 4D battery back up, the engine started. The upgraded electrical system was done by a professional marine services company ( according to the documentation on the boat ).

There are a maze of wires that lead to a custom board with shunts and connections. The wires are labeled but over the years, they have become faded and some are unreadable. There is a xantrex digital echo charger on the custom board too.

My dumb question is whether or not it's normal for the isolated starter battery to be tied into the house bank? Or is more likely that something has been mis-connected?

Any insights would be appreciated. Thanks
road_king_terp is offline  
Sponsored Links
Advertisement
 
post #2 of 18 Old 12-03-2018
Barquito
 
Barquito's Avatar
 
Join Date: Dec 2007
Location: Madison, WI
Posts: 3,337
Thanks: 1
Thanked 86 Times in 85 Posts
Rep Power: 12
 
Re: Dumb Electrical System Question

Welcome to SailNet! The starter battery needs to be tied into the other batteries if you want to charge all of them at the same time. Normally, there is a selector switch to choose which batteries you are drawing the juice from, and charging to. There are lots of ways to wire, and to use batteries, however, typically when you are motoring you would have the selector on BOTH to charge all batteries. When you are at anchor, you would switch to HOUSE to only discharge the house batteries. If you accidentally run the house batteries, you will still have the starter battery to fire up the engine.

Valiant 32
Barquito is online now  
post #3 of 18 Old 12-03-2018
Senior Member
 
Join Date: Oct 2011
Location: Nanaimo B.C.
Posts: 4,455
Thanks: 5
Thanked 137 Times in 136 Posts
Rep Power: 8
 
Re: Dumb Electrical System Question

Is it possible that you removed a common ground so things went dead. Maybe look for an either/neither switch and trace some cables too.
Capt Len is online now  
 
post #4 of 18 Old 12-03-2018
Senior Member
 
Join Date: Feb 2010
Location: Narragansett Bay
Posts: 19,526
Thanks: 82
Thanked 550 Times in 527 Posts
Rep Power: 11
   
Re: Dumb Electrical System Question

It's actually a good idea to have a selector switch, which allows one to use the house bank to start the engine, if the start battery dies. Could this switch exist and be set this way.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Jeanneau 54DS

In the harsh marine environment, something is always in need of repair. Margaritas fix everything.
Minnewaska is offline  
post #5 of 18 Old 12-03-2018
Moderator
 
MarkofSeaLife's Avatar
 
Join Date: Nov 2010
Location: London!
Posts: 6,183
Thanks: 62
Thanked 285 Times in 258 Posts
Rep Power: 10
 
Dock
Re: Dumb Electrical System Question

The starter battery should be able to start the engine by itself no matter whats going on with the house Bank.

As a non - electrician I can tell you I have never had one in my boat who does anything but slag off previous electrical work... but all has been done by professionals! So I reckon none know anything. (Except MaineSail, but he's in Maine).

So slowly work out what you want and get it installed and proved to work the way you want it before you pay the bill.

My banks appear to have been separated. Thats fine, as long as they both charge. What I did to solve the problem of an accidental drained starter battery was to put in a jumper lead cable just in case. If I ever need it I can wire it up in 3 minutes. Cost: Zero.

Sea Life
Notes on a Circumnavigation:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


People can say they want freedom, but offer them the keys to what chains them, a map to where they want to go,
And they'll turn it down for the cell they know
MarkofSeaLife is offline  
post #6 of 18 Old 12-03-2018
Learning the HARD way...
 
eherlihy's Avatar
 
Join Date: Jan 2007
Location: Boston / Ft Myers Area
Posts: 6,720
Thanks: 389
Thanked 284 Times in 279 Posts
Rep Power: 13
 
Re: Dumb Electrical System Question

The first thing that you should do is get a current working diagram of your primary electrical system. Do it yourself or pay someone to do it. It will save you time and aggravation in the future.

For example; this is the current version of my electrical system:


It's not fancy, but it helps me, and I maintain this as a guide.

Here is what the engine manufacturer provided;
Attached Thumbnails
2017 Schematic.jpg   Engine Wiring Harness.jpg   Engine Wiring harness diagram.jpg  
BarryL and SanderO like this.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

USCG Licensed OUPV Captain, ASA 101/103/104/105/106/114/118 Instructor - Also certified in Marine Electrical Systems


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
eherlihy is online now  
post #7 of 18 Old 12-03-2018
Senior Member
 
Join Date: Aug 2010
Location: The Bahamas
Posts: 3,403
Thanks: 3
Thanked 127 Times in 125 Posts
Rep Power: 10
 
Re: Dumb Electrical System Question

The separate dedicated starter battery system with its various tendrils and whatevers seems very antiquated.
If you like worry beads, a $100 Li batt starter pack will spin her into orbit....with fewer worries
RegisteredUser is online now  
post #8 of 18 Old 12-03-2018
Super Moderator
 
Maine Sail's Avatar
 
Join Date: Jan 2003
Location: Maine Coast
Posts: 6,673
Thanks: 31
Thanked 357 Times in 277 Posts
Rep Power: 10
       
Re: Dumb Electrical System Question

Quote:
Originally Posted by road_king_terp View Post
My understanding is that the starter battery is supposed to be isolated and completely dedicated to starting the engine.

My dumb question is whether or not it's normal for the isolated starter battery to be tied into the house bank? Or is more likely that something has been mis-connected?

Tell us what you have for a battery switch set up and we may be able to help. A large majority of boats do not use a dedicated starting only battery. This is because they use the very common 1/2/BOTH switch...

If you could list the switches and their labels, or even better, draw us a diagram of the positive battery wires and switches it would help us help you..

______
-Maine Sail / CS-36T


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.




© Images In Posts Property of Compass Marine Inc.


Maine Sail is offline  
post #9 of 18 Old 12-03-2018
Senior Member
 
SanderO's Avatar
 
Join Date: Jul 2007
Location: Northport, NY
Posts: 3,205
Thanks: 2
Thanked 87 Times in 87 Posts
Rep Power: 13
 
Re: Dumb Electrical System Question

Quote:
Originally Posted by Maine Sail View Post
Tell us what you have for a battery switch set up and we may be able to help. A large majority of boats do not use a dedicated starting only battery. This is because they use the very common 1/2/BOTH switch...

If you could list the switches and their labels, or even better, draw us a diagram of the positive battery wires and switches it would help us help you..
a few pics are worth a thousand words....

pay attention... someone's life depends on it
SanderO is online now  
post #10 of 18 Old 12-03-2018
Senior Member
 
fallard's Avatar
 
Join Date: Nov 2009
Location: Mystic
Posts: 2,273
Thanks: 15
Thanked 80 Times in 79 Posts
Rep Power: 10
 
Re: Dumb Electrical System Question

Quote:
Originally Posted by Minnewaska View Post
It's actually a good idea to have a selector switch, which allows one to use the house bank to start the engine, if the start battery dies. Could this switch exist and be set this way.
When I discovered that my house batteries could not be used to start the motor, I fixed the problem by adding another switch. Now, if the starting battery dies—as it once did at an inconvenience moment— I can switch over to the house batteries.

BTW, since the starting battery and house batteries are different sizes, it took me 2 hours to swap out the starting battery and tie down the larger house battery. That lost time meant I made the passage westward in the Cape Cod Canal with a 7 kt current. Glad the RR bridge wasn’t down!
fallard is online now  
Reply

Tags
battery , electrical

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Simple electrical system question radioguy Electrical Systems 9 08-15-2010 08:25 PM
Dumb question on shoes triracer320 Learning to Sail 60 08-03-2007 09:50 PM
Another dumb engine question lauralee Gear & Maintenance 3 05-06-2003 06:17 AM
Boat Weight (Dumb Question) swingnamiss Boat Review and Purchase Forum 2 01-12-2002 07:21 AM
maybe dumb blister question bruce123 Boat Review and Purchase Forum 1 09-01-2001 03:11 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome