A tale of battery cables

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KitCarlson

KitCarlson

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I recently discovered that my battery cables needed help. I was in my low 20's and needed to replace the battery cables around 1980. I took the cables to a farm store and match the length as close as I could with just few inches of excess. I found that is was possible to pull the old starter cable out of the protective wrap that also held the solenoid wire. The new cable was inserted. All was well for about 36 years, both me and the car getting a day older at a time.

The car started easy, with the exception of cranking a few second to get fuel to the carb when not driven for weeks. Recently I did more cranking when testing the COP ignition, I found that cranking was degraded. I measured voltage drops from battery to starter just below 1V and battery to ground about 0.5V. The service manual suggests voltage drops below 0.2V. Closer inspection revealed the cable insulation shrunk over time, exposing the shiny conductors, and a few of the strands had become broken at each end. I did some research on battery cables and found original spec and look show cables to be crazy expensive, perhaps 10x what a universal cable would cost.

I researched buying bulk cable, terminal ends, custom cable and found to get a good price on cable I would need to buy at least 25' to 100', and also order multiple terminals. With additional postage cost I decided to go local and get SuperStart terminals from O'reilly Auto Parts. The plan was to replace the lead terminals with copper stud terminals, and terminate the cable ends with crimped lugs. The stud terminals would be great to add accessory wire feeds, and also the cables could be changed out easily, if I found they needed improvement.

The #4 cables were cut slightly shorter and terminated by crimping on #4 copper lugs using a crimp die fabricated from 1" x 1/2" steel bar stock. I used a vise to clamp the die for the ground cable, and a huge vise grip for the battery end of the starter cable. I am waiting to change the starter lug when the starter is changed out to a recently purchased min-starter.
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The first crank was impressive, actually the sound was very sweet, smooth and fast. I think that sound was long forgotten over the years. I feel a bit silly to have bought the mini-starter, but the permanent magnets replacing the field coils, lighter weight, and good reports, are still good reasons.

I hope to get help from the wife so I can take new voltage drop readings, and report on difference in starting currents.
 
Do you know what was specifically wrong with the old ones, or just "general" corrosion?

I REALLY don't care for "the looks" of the new "tinny" battery clamps. Interesting that they seem to work better
 
67Dart273 said:
Do you know what was specifically wrong with the old ones, or just "general" corrosion?

I REALLY don't care for "the looks" of the new "tinny" battery clamps. Interesting that they seem to work better
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I found that the lug terminal was a solder melt, not a crimp. The battery terminal ends seem to have released or corroded some in the lead. The most significant problem was broken strands at each end, enough that the cable capacity was diminished.

I thought that the tinny clamps look cheap, but they are well plated and springy, as if they are a copper beryllium alloy. I have an 11 year old daily driver, the stamped terminals still look like new.

Lead has 12.6 times the resistance of copper, so they have to be much thicker to conduct as well. The problem with lead is, it is hard for it to mate well with battery terminal, after reuse and cleaning. I have tried to find tapered terminal reamers, but all I find are battery brushes. Even careful use of a straight edge of a pocket knife, results in high and low spots, so the mating surface becomes a smaller percentage. The terminals were clean, and measured drop was near zero measured between post and lead, so I am thinking more to do with loss of strands and the soldered lug. The new terminals can be mounted low on the battery posts for less resistance, I removed the felt washers to get to the very bottom. The improvement in cranking was exceptional, even without the starter lug being replaced. I measured the before cranking speed of only 138 RPM. When I re-install the COP ignition I will re-measure. Listening seems like much higher.

When it gets very humid here, I have trouble with my Massey Ferguson tractor terminals. The mice build nests, and pee on them in the winter, the summer humidity corrodes lead like crazy, with pockets of black crud inside. My solution this year will be to replace the ends. I bought brass ends, but they have a strap with two bolts, not sure if I will use those, but keep them in the tool box to perhaps save the day.
 
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I made a similar die I use in a press. I still try and sweat some solder in the ends and then slide some shrink tubing over them.
 
Although I have yet to install them, I found some NOS made in USA NAPA Belden cables for my truck on Ebay. They are both 1 ga.
 
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mguner said:
I made a similar die I use in a press. I still try and sweat some solder in the ends and then slide some shrink tubing over them.
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There is much controversy about the use of solder in high current connections. I follow the faith of of good solder less crimps. Solder introduces a less conductive metal, the soldering temperature messes with copper hardness near joint. It was apparent that strand failures were experienced in the cables, were likely related to solder process on lug end, and lead cast on the other.
 
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RustyRatRod said:
Although I have yet to install them, I found some NOS made in USE NAPA Belden cables for my truck on Ebay. They are both 1 ga.
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1 ga is nice. I will keep NOS NAPA in mind.

I tried to find original size and length, for 66 Barrracuda, with uncertainty 6 ga, 19" ground, 38" starter with 12 ga switch wire. Seems 6 ga would be marginal.
 
KitCarlson said:
There is much controversy about the use of solder in high current connections. I follow the faith of of good solder less crimps. Solder introduces a less conductive metal, the soldering temperature messes with copper hardness near joint. It was apparent that strand failures were experienced in the cables, were likely related to solder process on lug end, and lead cast on the other.
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Do you honestly think solder makes enough of a difference to be that picky about? I wouldn't think it would much to worry over........but then my knowledge of things electrical is lacking. Among other things.
 
RustyRatRod said:
Do you honestly think solder makes enough of a difference to be that picky about? I wouldn't think it would much to worry over........but then my knowledge of things electrical is lacking. Among other things.
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I guess it depends on many factors. I have found in 45+ years of soldering wires, that with vibration and age they fail just past the solder.

I also know a good mechanical connection must first be made prior to soldering. The concept of pellet soldering a lug seems flawed, because the connection must be loose to get the cable inserted. The solder is about 10 times less conductive than copper, so compared to a crimp the conductivity is less.

If the connection is properly crimped, then soldered, solder leaches in at an atomic level, again resulting in less conductivity. The heat during soldering aneals the copper where it cools quickly, and hardens where it cools slowly. Copper easily work hardens, so breakage often happens close to joint.

I am also familiar with what can happen with loose soldered joints with high currents, solder vaporizes. This can happen in fractions of a second. I have verified this many times in lab tests related to product development.

I don't worry about it. While my newly terminated old cables may last another 35 years, that is well beyond my estimated lifespan.
 
That's interesting. Thanks. I had no idea solder was that much less conductive.
 
Rob wrote: "I had no idea solder was that much less conductive."

It's not. It's a very good conductor. KitCarlson said only that lead doesn't conduct at well as copper, but the lead in solder doesn't do the conduction. Solder is at least 30% tin, which is a very good conductor.
 
KitCarlson said:
I guess it depends on many factors. I have found in 45+ years of soldering wires, that with vibration and age they fail just past the solder.
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I'll 2nd this... I soldered connections in may early rally cars but stopped after they started breaking right where Kit says. If you solder connections, you have to solidly support the wires a few inches past the end of the solder to prevent this problem.

BTW, the conductivity of solder is right around 1/10th that of copper.
 
nm9stheham said:
I'll 2nd this... I soldered connections in may early rally cars but stopped after they started breaking right where Kit says. If you solder connections, you have to solidly support the wires a few inches past the end of the solder to prevent this problem.

BTW, the conductivity of solder is right around 1/10th that of copper.
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Something you notice but don't really put together in your head (heat affected metal). I guess I'll just be happy with my press die and shrink tubing from now on! :)
 
KitCarlson, pardon me if I missed this, but how do you prevent corrosion from getting started between the crimped metals?

I admit that I am probably biased because I've been soldering since I was a kid, and maybe I inhaled too much lead vapor and flux fumes, but IMHO soldered connections are peachy keen.
 
Bill Crowell said:
KitCarlson, pardon me if I missed this, but how do you prevent corrosion from getting started between the crimped metals?

I admit that I am probably biased because I've been soldering since I was a kid, and maybe I inhaled too much lead vapor and flux fumes, but IMHO soldered connections are peachy keen.
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Solder works for low current electronic connections that are well mechanically supported. High currents and solder, a completely different thing. Some solder fluxes promote future corrosion, not prevent it. I am not unique in my experience and knowledge.

The lug, is a copper closed end barrel. A good crimp is air tight. Heat shrink was used to enclose the lug and cable insulation.
 
What would the effects of a urethane type adhesive / sealant like Gorilla Glue be if used with a crimp like discussed?
 
I think urethane and neutral cure (non-corrosive) silicone sealants should work. Some use brush-on liquid electrical tape in a can.

Crimp first, seal last.
 
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KitCarlson is right on about potential problems with soldered connections. If only a small amount of excess heat is applied, the solder wicks up the wire, often inside where it's not visible. That point is the weakest part of the wire and even minor vibrations work-harden the strands so they break easier. This was a severe problem with early spacecraft and bad solder joints caused many catastrophic failures. Responsible manufacturers made sure that all solder joints were carefully inspected, and NASA operator certification was required for anyone making a solder joint for their programs.

Info for the DIY folks: it's also critical that you use non-activated solder. If not, corrosion will begin immediately.

If you really know what you are doing, solder is fine, but if done by someone not properly trained, it will fail long before a good mechanical crimp.
 
As we were discussing this subject at the counter we also talked about converting worn out bolt cutter blades to crimpers..... :)
 
mguner said:
What would the effects of a urethane type adhesive / sealant like Gorilla Glue be if used with a crimp like discussed?
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Use a heat shrink tube that is 'flooded'. It has a goop in the inside that liquifies and flows as the heat is applied and gives a decent moisture seal where the tubing meets the wire and metal. This heat shrink has a shiney look on the inside, and there will be a thin bead of yelllowish or clear goop at then heatshrink tube ends when done.
 
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