MacGregorSailors.com

Hello!
I know wiring/battery setup is a common thread on this board; however, my system and question is so simple, I have not yet discovered the answer. I am an electrical novice and don't want to make a false assumption that could lead to trouble.

I have a 2000 26X that I want to eventually install the Blue Sea 7655 Mini Add-A-Battery Plus Kit - 10A (7655). However, a few other projects (the ones at the top of my wife's list:-) will take precedence this summer. My goal for this summer is to just clean up a single battery wire mess.

Current setup: all accessories run to my boat's switch/fuse panel and then to my battery. On my battery posts I have a stack of about six wires, both on the positive and negative side. I always pack along a spare charged battery just as a backup, it is not wired into the system (again, waiting until I can purchase the Blue Sea system).

My question: Can I simply install one bus for all my positive wires with a single connection to the positive battery post and one bus for all my negative wires with a single connection to the negative battery post? My goal is to eliminate having to take six accessory wires off both the negative and positive post every time I charge my battery, reconnect my battery, swap batteries, etc. My plan would be to just install the busses down in the battery compartment, close to the battery with a very short run from the busses to the battery posts.

I think one of the reasons I am confused is that any diagrams I have viewed show only one positive wire leading from the switch/fuse panel; however, I believe I have one positive wire for every fuse (I have not looked this season, just going from memory). I want to combine all of these positives (and the negatives) on one bus (one bus for pos one for neg) before running just one wire from the bus to my battery. Is this just such a simple concept that there is no need to actually include the bus in the diagram or am I missing something here?

Thanks for your help!

Welcome aboard Brian!

Yes, the buss bars setup as you've described is the best way to do it. A lot of basic boats do not come that way from the factory for cost saving and usually have few electrical accessories. The most efficient way is to have the fewest wires going to the battery, but it is not the rule.

Multiple conductors on the battery terminal(s) is considered poor practice. Since you have a distribution panel, there should be a single positive and a single negative conductor to that panel, with a fuse at the battery large enough to handle the combined load. The conductors must also be sized to handle the combined loads.

That's assuming there's no outboard (OB). If there is, those cables should go directly to the battery, or if a disconnect is used, to the disconnect, along with the "+" feeder to the panel.

If the panel doesn't have a "-" bus, you can add one next to it for all the branch circuits, which is what I did. MacGregor just put ring terminals on all the negative conductors and used a bolt to hold them together. Unless they didn't do it. But either way -

You will find in the pedestal it has the exact setup you describe, common negative and common positive bus to save running all those wires back to the switch panel

I,m in the process of up-dating my battery wiring also & doing the same mod , I,ll b installing these products when I get my boat out of the boat yrd next mon

These will be going on my #1 house battery bank
http://i844.photobucket.com/albums/ab1/ ... 6l6xa0.jpg

I already have one of these on my start battery also
http://i844.photobucket.com/albums/ab1/ ... 5rczee.jpg

hope this helps u out

J

Thanks everyone for your helpful input! I'm looking forward to getting this done.
Happy sailing!
Brian

Brian W wrote: I know wiring/battery setup is a common thread on this board; however, my system and question is so simple, I have not yet discovered the answer. I am an electrical novice and don't want to make a false assumption that could lead to trouble.

Brian, 12V DC electrical is very very simple, by itself. That is one of the reasons it gets hacked so badly, and often still works! It is not uncommon at all to hear the chorus "It looked like spaghetti, I'm surprised anything worked at all!", or any of a hundred variants. Yet, cobbled together as the components often are, the electrons somehow find their way home, and the lights light up and the radio turns on...

So the idea of a bus bar is one of convenience, safety, and clarity more than necessity. As long as those red wires touch the positive terminal, and the black wires are touching the negative terminal, the device will likely work. But as you are finding out, maintenance, charging, additions or removals...are all difficult. If you move all of the individual device wires to common sets of connected terminals, bus bars of sorts, and you connect one larger wire from each of those common terminals to the battery (usually thru a large switch and a fuse), it will indeed work identically the same as if it was connected directly to the battery. There are just a significant number of "what if" scenarios that have been worked out over the decades to prevent electrical fires, shock injuries, equipment failures, and the like. This is where having a significant level of input helps.

So feel free to ask. There are usually several safe, efficient ways to skin the proverbial cat, but in the end, sticking to those same safety-focused principals are what really matters.

Sumner has posted about these battery post fuses.
https://www.bluesea.com/products/5191/M ... 30_to_300A

They are a very cool way to fuse close to the battery. If you are using a bus bar, I'd put one of these on top of your battery post positive terminal.

I think you will find in the pedestal there is a common negative bus and common positive already, well certainly on mine there is, this makes running electrics around the cockpit easy.

I think there "may' be a the same setup between the front windows, Im exploring that at the moment with my wiring but I cant see them running all the wires so far when a simple bus system would shorten the wires and make thunks easier in the production process