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Discussion Starter · #1 ·
I seem to have some excessive voltage drops, between the battery and starter motor, and between battery and breaker panel. It looks like I'm going to need new cables.

Can anyone recommend a place that supplies battery cables made to order, probably by mail?
 

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I seem to have some excessive voltage drops, between the battery and starter motor, and between battery and breaker panel. It looks like I'm going to need new cables.

Can anyone recommend a place that supplies battery cables made to order, probably by mail?
Mark,

Unless you measure exactly, plan very, very, very carefully, get every lug hole size correct and the angles right, then making your own will be the best bet.

Buy the good tool from KL Jack and sell it here for $40.00 less when you are done. Someone will snap it up in a hear beat. In the end you are out $40.00 but will have better, neater wiring with more exact lengths of wire... Trust me there are things that can't be accounted for in a re-wire with larger cable.

If doing one wire then ordering pre-made can work fine but for all your heavy gauge wiring just buy the right tool and sell it when the job is done...
 

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Discussion Starter · #4 ·
Thanks for the info Maine Sail. I like the idea of making the cables, but that site looks great for custom cables, too.

So as far as cable sizing goes, what would you use for a 12ft run (each way) to a 1 litre diesel with a 1500W starter (should be 140A).

The calculator on that site indicates 1/0 gauge will give me a voltage drop at the starter of 0.34V, or 2.8%. Sounds reasonable to me, what do you think?
 

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When I made new battery cables my local chandler lent me the lug crimping tool.
 

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Are you certain the cables themselves are bad and not just the connections to the starter or neg bus? Corrosion can be between the connector and terminal, while it looks visually clean from above. I've cleaned these all up and applied dielectric grease and often noticed a dramatic improvement.

If you do need cables, its the perfect excuse to buy the tool. Even if you exactly measure what you have, you'll undoubtedly find that a small re-route or another inch or two could make all the difference in your install when you get down to it. The manufacturer would have been looking for the least expensive build, but for a few more inches on DIY cables, you might really improve serviceability. It would be nice to be able to do that on the fly.

Also, I've replaced batteries over the years, with lugs in slightly difference places or even different sizes. So far, I've managed to stretch or scrunch the old cables to work or even used terminal adapters. A few times, it would have been really nice to just make a new cable, but I could not justify buying the crimper just to make one jumper.
 
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Thanks for the info Maine Sail. I like the idea of making the cables, but that site looks great for custom cables, too.

So as far as cable sizing goes, what would you use for a 12ft run (each way) to a 1 litre diesel with a 1500W starter (should be 140A).

The calculator on that site indicates 1/0 gauge will give me a voltage drop at the starter of 0.34V, or 2.8%. Sounds reasonable to me, what do you think?
Mark,

The in-rush will be 250A - 400A+ and loaded cranking will generally be more than 140A. Starters are an odd lot ratings wise. That said I would probably choose 2/0 on a 24' run but 1/0 will certainly do it and do it better than what the factory likely used..
 

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Discussion Starter · #8 ·
Well the cables to the starting battery look horrible. Untinned wire, no heat shrink, sheath cut to the wrong length, and badly done crimps. So I'm pretty sure they should be replaced regardless.

2/0 is fine, I can use that.

What started this, is the starter turns over quite slowly (and now and then just goes click) on the starting battery. It's better on the house bank. But, the starter battery only drops to 11.5V under starting load, so I think it's strong.

Also, all the instruments reboot when I hit the starter, which I'd like to fix.

So I think I need to take some detailed measurements of voltage drops between the battery and the starter, as a benchmark before I start trying to improve it.
 

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Discussion Starter · #10 ·
Usually, my approach to any job is if I can do it myself but need to buy a tool, I will. The tool will more or less pay for itself, and nice tools have a value all of their own.
 

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Mark--

A few years ago I did the electrics on our (then) newly installed Maxwell VC1500 Windlass which involved two 45' runs of 2/0 wire as well as fitting numerous lugs to the cables. I found the least costly, best quality, cable was manufactured by Pacer Marine of Sarasota, Florida (compared with West Marine, GenuineDealz and a number of similar competitors). And, my cost through Pacer came in at well under 50% of the cost through West Marine as a comparison.

Measure your cable dimensions carefully. The best way to do that is not with a tape measure directly but by marking a length of 1/2" or 5/8" diameter line laid down following the path your cables will need to take. Then add a foot or so to each cable just to be safe when you trim the cables to final length. Measure the terminal posts for the size connectors you will need for your lugs so that the lugs fit the terminal posts properly. Pacer has proper brazed copper lugs for each of its cable sizes to fit various terminal/battery posts . They also have excellent quality adhesive heat shrink tubing in various colors to cover the lug/wire connections and various terminal boots to protect the terminals once the wiring is finally connected up.

Rather than a spacial tool for crimping wire, I used a Swage It Tool that can be used elsewhere on the boat for other projects later on and does an excellent job of compressing lugs around the cable wire bundles. Because twisting wire can be difficult, I found the best way the connect the lugs was to loosely connect the lugs to each terminal post and to run the wire between lugs so that it takes the lay it wants between either end without the need of twisting. One then slips a length of heat shrink tubing over the cable and slips the prepared end of the cable wire bundle into the lug and holds the cable and lug in place/position for swaging with a wrap of tape that can be removed before the heat shrink is shrunk in place.

To prepare the cable ends, I found the use of plastic zip ties very helpful. For cutting the cable, attach a zip tie closely on either side at the point the cut is to be made. A Dremel tool with a reinforced cut-off wheel makes quick work of the cable and leaves clean, square ends on the wire. One than measures the length one needs for insertion in the lugs and adds a second zip tie just beyond that point on the cable. The cable insulation can then be cut and removed from the cable end with an Exacto tool or razor knife. With that, the wire bundle can be splayed out somewhat and dielectric grease worked into the strands. The inboard zip tie is then worked toward the cable end and tightened around the exposed wire bundle as it slips over the edge of the trimmed insulation. By working it out to nearly the end of the cable, the wire bundle is held tightly together and can easily be inserted into the lug positioned on the terminal terminal post in question. As the wire is pressed home into the lug, the zip tie is forced back, toward the trimmed insulation cover, where it can be cut with an Exacto tool or razor knife and removed and the lug flushed out and taped in place for swaging as described above.

The foregoing takes rather longer/more effort to describe than it does to actually do. With the foregoing methods, I found that I ended up with nicely finished connections with no "twists" in the cables and an economical installation.

FWIW...
 
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Since you asked about "mail order" - For the very best prices, service and FREE shipping, I exclusively use Marine Wiring, Boat Cable and Electrical Genuinedealz.com. They use only high-grade marine tinned cable, and will properly crimp end connectors (they also sell all the necessary bits and bobs) for only $1 per crimp. This includes installing adhesive-lined heat shrink (which you have to buy also, but it's cheap). As much as I love having tools - how many crimps can you have custom-done at a buck apiece for the price of a heavy gauge crimper?

As far as measuring wire runs for heavy cable, I would suggest using a length of similar-sized hose in order to get a more accurate dimension. Tape measures do not bend in nice arcs, and tend to fold up going around corners.

No affiliation - I have used these folks for years and they are GREAT! Good luck with your project! ;)
 

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Discussion Starter · #13 ·
So one thing I just changed was the wierd switching arrangement Universal used. You had to have the glow plug button pressed, for the starter to work. Well that's 40A drain that can be subtracted from what's available for the starter.

I tried it, holding the glow plug button and then quickly releasing it and pressing the starter. It definitely turned over better than it did before the change.
 

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Discussion Starter · #14 ·
"Rather than a spacial tool for crimping wire, I used a Swage It Tool that can be used elsewhere on the boat for other projects later on and does an excellent job of compressing lugs around the cable wire bundles."

That's very interesting because I already have one of those! How do you know which hole to use for which crimp size?
 

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"Rather than a spacial tool for crimping wire, I used a Swage It Tool that can be used elsewhere on the boat for other projects later on and does an excellent job of compressing lugs around the cable wire bundles."

That's very interesting because I already have one of those! How do you know which hole to use for which crimp size?
You will need to ruin a few terminal and experiment. There should be no "pinch" or "tags" but it should be well compressed. A properly crimped 1/0 lug should hold at least 700 pounds of load.....
 

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Mark, a number of forums members have used Marine Wiring, Boat Cable and Electrical Genuinedealz.com over the years and everyone seems uniformly happy. You select the wire, the lugs, all top quality tinned, etc., and literally for a pittance more, they'll professionally crimp them and assemble them for you. Nice product, prices are competitive with just buying cable by the foot.

I'd suggest that if you have any odd non-linear runs, you can buy some cheap vinyl tubing at the hardware store, and actually see how it is going to fit to curves, to get a more accurate length than just trying to string a tape out from here to there. Or a length of stiff old 5/8 line, etc.

Do remember to provide for a primary battery fuse location, and the "last foot" beyond that.
 

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Discussion Starter · #17 ·
Is a fuse near the battery worth adding? Right now there's nothing.
 

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Unheard of before the 80's, now required by pretty much every code and safety standard.

The battery primary fuse is there to prevent a disaster, like a crowbar short. If you drop a wrench across the cables, or an anchor shorts them out, or any other unlikely event allows you to have literally a 3000-10000A short in the primary cables....that fuse will be money well spent. A single Group27 SLI battery will gladly put 3500A into a dead short, and then something is likely to either combust or explode.

Worth fusing?
 

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"Rather than a spacial tool for crimping wire, I used a Swage It Tool that can be used elsewhere on the boat for other projects later on and does an excellent job of compressing lugs around the cable wire bundles."

That's very interesting because I already have one of those! How do you know which hole to use for which crimp size?
Simply measure the size of the exposed wire bundle and then use a matching or the next larger die in your SwageIt tool. Depending upon which size tool you have, you may have to start with a somewhat larger die and once the lug is compressed down somewhat, adjust to the next smaller die. The lugs will compress around the wire nicely and as the pressure comes on the copper in the lug will somewhat "flow" around the wiring bundle. As a follow up on Pacer Marine, it's cable is made right in Sarasota Florida as it has been for many years and is very highly rated by the power industry, far better than cable imported from the far east.

FWIW...
 
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