Battery Question...

onlinelee

onlinelee

.
Apr 8, 2016
114
Beneteau 361 Clipper Garrucha, Spain
Hi Friends,
Would appreciate if you guys could take a look at the attached photo of my AGM battery bank wired in parallel. I am a newbie in regards to boat electrics and have a lot to learn but it seems to me the installer of these batteries has made a mistake. According to Nigel Calder the positive and negatives going to the boats circuits should be taken from opposing ends of the bank to ensure the batteries are charged and discharged equally, this does not seem to be the case here. Has it been done this way due to some quirky way Beneteau wire their boats, as suggested by another Beneteau owner? Is there any reason I can't just correct the error, assuming there is one? Thanks in advance.
IMG-0020.JPG
 
kloudie1

kloudie1

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Nov 6, 2006
9,894
Hunter 34 Mandeville Louisiana
Looks like you can take the positive cable that goes to the boat and move it to the positive post on the bottom left, the batteries would be wired correc tly to balance things electrically. It looks like there is enough slack in the cable to do it.. leave the other stuff as-is.
 
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stevemitchell

stevemitchell

.
Jan 12, 2016
140
Beneteau 311 Seattle, WA
Stu Jackson said:
Kloudie's right. But you may want to consider marking the + in RED!!!
Click to expand
Excellent suggestion. I had a similar setup on my boat and immediately marked them all. Would really suck to have to take one of those out, disconnect the cables, and then not know what is what...
 
J

JimInPB

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Aug 22, 2017
1,609
Hunter 26.5 West Palm Beach
Yea... drawing both the positive & negative off the same side of the battery bank is not the absolute best way to run the cables, but it's a small issue. Swap the one cable over to the other side of the bank when you get around to it. I wouldn't loose any sleep over not getting to it promptly.

I would be more worried about the color coding. I would invest in some red shrink tube.

Edit:
Actually, on second thought, I would leave it as-is for now. Since the jumper cables are each separate, a loose bolt in the middle of the bank could make funny things happen.

I would have those cables remade or get new cables made up that have 2 cables into a single lug for the jumpers & after those are made up, then I would switch to drawing negative & positive off of opposite sides.
 
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Ron20324

Ron20324

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Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
If it were my boat, I'd make it right, right now- it's not a major effort. And I'd make all of the cables like the size of the larger of the two sizes. Remember, the larger cable is carrying the amps of TWO batteries, so make sure it is sized properly! If not, then at the very least shift the small cables to bridge the middle and non- power take-offs, which is what you have now.I can't read the size of the cables, but the ones that are smaller don't look like the right size for this purpose. Yeah, get some heat shrink on the positive cable- or some paint.
 
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jviss

jviss

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Feb 5, 2004
6,748
Tartan 3800 20 Westport, MA
There really should be some air-gap between those batteries, for proper cooling. And, I agree with others, get some red vinyl tape and color-code those positive wires.
 
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J

jeepbluetj

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Jan 18, 2016
782
Catalina 387 Dana Point
JimInPB said:
Yea... drawing both the positive & negative off the same side of the battery bank is not the absolute best way to run the cables, but it's a small issue. Swap the one cable over to the other side of the bank when you get around to it. I wouldn't loose any sleep over not getting to it promptly.

I would be more worried about the color coding. I would invest in some red shrink tube.
Click to expand
Yup. For a 100A draw it does indeed makesa difference. For a 5A draw, who cares. Having the right color coding on the cables would be far higher up on my list than trying to balance the draw/charge cable lengths.

For all the stuff most boaters worry about, they'd be far better ignoring. Batteries? Keep em 100% charged, and don't go below 50% or so. Do that and you'll have happy batteries. Let em dry out, draw to nothing, etc., you'll kill em. How they're wired is waaaaay below the most common causes of battery death.
 
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J

JimInPB

.
Aug 22, 2017
1,609
Hunter 26.5 West Palm Beach
jviss said:
There really should be some air-gap between those batteries, for proper cooling.
Click to expand
This is a real good point, especially since you have AGMs. AGM batteries have a reputation for accepting very high charge currents when they are substantially discharged, so you should probably keep an eye on battery temperature the next time they get a hard charge & see if you are getting temperatures that are high enough to worry about.
 
Gunni

Gunni

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Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
No battery tie-downs. Boats sometimes roll way off level.
 
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