Technical Cable for battery

i thought soldering, just like using solid conductors, was x-nay on things which vibrated when in use.

(boats/ planes/ cars)

stranded & crimped [w/ adhesive heat shrink if possible.]

 

If a connector is staked right, tough, it'll outlive our grandkids on something this big. Even crimp ends are good if done right and shrink tubed on regular stuff. A lotta guys fuck up and punch the split side. I know rosin is preferable, but so far no fails here in the Highlands

Ok Monroe ain't the Highlands but it's my story

 

Crimp ends are the best way to complete a wire connection. Soldering wicks up the cable and can cause failures, plus it adds resistance to the connection. And if somebody ever has a tough start issue and heats up the soldered connection it will fail and then you're in big trouble. I use a Greenlee crimper for all my connections, and I buy batteries with side terminals so I can bolt on the cables for a solid connecttion.

 

Saw a video where.you cut a Nut in half smaller than the connector size and then crimp said connector in a vice / rotate and repeat ..Garage tip and trick..

 

When I did my 49 Dodge truck, the battery is in the front of the bed, I wanted/needed 12' of red wire, and 12' of black wire for the battery cables. When I went looking for the wire choices, there was no #4 (the largest battery cable available) "battery cables" longer then 79", or I could buy 25' lengths of individual color of #2 wire (figured that was better then #4 wire) for around $18 each (10' lengths were also available, but those were too short to make the reach). Then I saw a 20' long set of #2 jumper cables with red and black coated wires, on sale for $25. That choice was pretty easy. I bought and cut up the jumper cables.

 

I just stated some facts, that's all... I would like to see some reputable engineering data on 'intermittent vs continuous rating' and the 'denser' things however.

 

By golly this joint never disappoints. We talk about a good battery cable then get the most intricate of technical analysis like amp draw, voltage drop, insulation, and more. That said, what of the magnetic fields created as current goes thru? Are now having to ground the cable to the frame too like Vette plug wires? Will it muller up our sound systems or open garage doors with magnetic wave signals? Are we gonna trip electronic emergency trailer brakes on big rigs? So many things to consider!




Ok, I'm being a dick again but you love it

 

it's good that someone sees the light

 

"Continuous" would typically be a duration of >90 seconds. The current drawn when cranking the starter would be considered "intermittent".

For example, at my place of employment we will spec a 2/0 cable for 175A max (continuous) and 1000A max (intermittent). This covers our general current draw during machine operation and charging, but also accommodates the current draw during engine start.

You wouldn't spec a 8/0 or some ridiculously sized cable to account for starter current draw. Our engineering design charts - which top out at 4/0 - don't even list a cable large enough to account for the 800A we see during starting as a continuous rating.


The "denser" cable thing, though, beats the heck out of me. X AWG welding cable is going to have the same ampacity as X AWG battery cable. The finer strands might allow the cable to reach the necessary CSA in a smaller overall diameter since less space is wasted between strands, but it's not going to affect the DC ampacity of the cable.

 

I have used them a couple of times. Great quality, fast turn around, decent price!

 

I’ve said this before, and I’ll say it again: electricity hurts my head.

 

[QUOTE="chickenridgerods, post: 15614140, member: 1521"
The "denser" cable thing, though, beats the heck out of me. X AWG welding cable is going to have the same ampacity as X AWG battery cable. The finer strands might allow the cable to reach the necessary CSA in a smaller overall diameter since less space is wasted between strands, but it's not going to affect the DC ampacity of the cable.[/QUOTE]

The smallest diameter and densest a conductor can be is one solid copper wire. So if your wire is made up of thousands of tiny strands in a similar diameter it's closer to what one solid conductor can be than say the usual multi strand conductors that have a lot of open space between strands doing nothing.
A 2/0 welding cable is not smaller OD than a 2/0 house or commercial conductor, but because of the number of strands and the larger diameter it carries more current. Cable manufacturers all state that welding cable and battery cable are rated similarly for ampacity. I've asked this question of cable manufacturers as they don't list their battery cable amperage ratings, and that's the reply I got. One thing they did say is that welding cable has a more durable insulation from physical harm, but it also doesn't have the effectiveness of the plastic coating their battery cables have, so avoid spilling gas or oil on your welding cable. That's never been an issue for my cars, but guess it could be for some.

 

maybe you connected the wires backwards?

 

Welding leads is all I ever use on my oldies. It’s flexible and my 6 volt cars seem to start so much better.

 

A cable's gauge is measured by total cross-sectional area (CSA) of its conductors. A 2/0 welding cable has the same CSA as a 2/0 battery cable - hence why they're both "2/0".

For example:

A 2/0 welding cable will have (~1200) 30 AWG condutors. A 30 AWG conductor has a diameter of ~0.01" for a CSA of 7.85e-5 square inches. So, the 2/0 welding cable has a total CSA of 1200 * 7.85e-5 = 0.09 total square inches.

A 2/0 battery cable will have (~130) 20 AWG conductors. A 20 AWG conductor has a diameter of ~0.03" for a CSA 7.07e-4 square inches. So, the 2/0 battery cable has a total CSA of 130 * 7.07e-4 = 0.09 total square inches.

A cable with X CSA constructed of Y fine strands could theoretically be smaller in overall OD than a cable with X CSA constructed of Z coarse strands because of the reduction of wasted space between the individual strands. In reality, though, the OD will be more or less the same, especially if the finer strands are "rope laid".


Regarding the current carrying capability, you seem to keep trying to apply AC principles to DC circuits. DC current gets carried equally throughout the thickness of the conductors; it's not concentrated near the conductor's ODs like AC current. Since DC works across the entire area and a 2/0 cable has the same cross-sectional area regardless of construction, they all have the same DC current carrying capacity. A stranded (or more finely stranded) cable will have more current carrying capacity in an AC application because the strands have more total surface area along which the current can be carried; this phenomenon is called "skin effect".


SGX and STX type battery cable most certainly have a more robust and durable (PVC and XPLE) insulation than EPDM insulated welding cable. Both from an abrasion perspective and a chemical resistance perspective. EPDM is soft and gets mushy when exposed to chemicals. The SGX and STX are less flexible, however.

 

A 2/0 welding cable is much larger than a 2/0 AC electrical conductor. And that's not just because it's thicker insulation. I've compared them side by side and there's no comparison in diameter. Welding cable works, and everyone uses it, and has for many decades. Not sure why people still question something that's proven to work better.
There is no difference in current carrying capacity of a cable for AC vs. DC. Skin effect is usually related to AC conductors and how efficient they are at carrying current before they heat up. The skin effect simply cause the current flow to not use the entire cross sectional area and thus heats the conductor up. Not going to happen with your car battery or the short duration a starter cranks at.
Some of you guys seemed determined to dazzle us with your electrical knowledge vs. just accepting that welding cable works great for this application. I've been using it for many decades and never had a failure or a problem.

 

It would be an interesting experiment to cut precisely say 6" of battery 2/0 cable and 6" of welding 2/0 cable, strip the insulation off of each and weigh the copper.

Then we would know if one indeed has more conductor than the other, or if they are the same.

 

We're simply correcting mistakes in your claims regarding cable diameters and that welding cable has better ampacity than battery cable. Refer to your previous posts., such as the following:

A 2/0 welding cable is the same CSA as a 2/0 battery cable. I just gave you the math showing that. Now, note the following diameters of such cable.

2/0 Welding Cable:
Nominal OD 0.568"
Insulation thickness 0.080"
Conductor OD 0.408"
https://www.awcwire.com/product/weld-2_0

2/0 SGX Battery Cable:
Nominal OD 0.575"
Insulation thickness 0.065"
Conductor OD 0.445"
https://www.awcwire.com/product/sgx-2_0


Regarding durability, welding cable is probably fine for use in a hot rod. Just make sure it won't abrade against metal parts and doesn't get soaked with grease, oil, and fuel.

At my place of employment, which builds industrial equipment, we're moving away from allowing use of welding cable because of its insulation durability issues. Its use certainly would have helped me with some battery cable routes I had to come up with last month, but we have to use what's the least likely to have issues in 5-10-15 years.

 

Nothing wrong with welding wire.
I personally use 1 gauge fine stand purpose built wire. It's $5 or $6 a foot now.

 

You win!
But I'm still using welding cable regardless of what you or others state. My last build is 15 years old now, and lots of miles all over the country. Plus lots of runs down the drag strip. I think it's proven it's longevity to be just fine after 5-10-15 years

 

I use welding cable for batteries and battery cable for welding. Not really...just trying to get everyone amped up