Hey old, Battery cable gage

[Marv 984]

What do you think about using 6 gage for battery cables?

Marvin

[WH nut 553]

Id go a single 0 if it were me

[Save Old Iron 1,571]

#6 wire has a rating of 0.3951 ohms per 1000 feet.

 

We use what ? 3 feet maximum on a battery to starter run.

 

The 3 foot of wire has a   .3951 / 1000  *  3foot   resistance which equals  0.0011853 ohms.

 

Under a 40 amp draw the voltage drop across 3 feet of #6 is (40 * 0.0011853) or 0.047 volts.

 

The voltage drop caused by the wiring is insignificant compared to the resistance of corroded connections and half dead sulfated batteries.

 

My point here is even if you go one range AWG gauge smaller (or larger to show off to boys at the local tater diggin' festival), the voltage drop remains insignificant over such a short run of wire.

 

If you have #6, use it. I have jump started Kohlers with 12 gauge house wire without a problem. A reasonable wire gauge will never be the cause of slow cranking. Corroded connectors ON THE WIRE are more likely.

 

I should have a nice write up at SOI U in the coming weeks. Showing how to use voltage drops to identify corrosion on connections is the best way to trace down a hard start problem.

[Marv 984]

Thanks Old,

That confirms my thinking. Now to finds terminals for 5/16th bolts. Found 1/4 ok.

Marvin

[Save Old Iron 1,571]

You will use 4 terminals for the positive side wiring and 2 more for the negative side.

 

I usually buy a pack of 2 to 15 and have myself covered for the current tractor I'm working on plus some emergency spares. Seems like the only place you can do that reliably anymore is over the internet. These days, local suppliers tend to be disappointing with limited stock and waste my time and gas $$. Maybe I'll change my mind if the internet tax kicks in - who knows.

 

http://www.ebay.com/itm/15-6-gauge-X-5-16-inch-tinned-copper-lug-battery-cable-connector-terminal-UL-/370811955049?pt=LH_DefaultDomain_0&hash=item56561d6769

 

 

You can also pick up a good compression crimper for less than 15$

[JimmyJam 542]

Ok, I am kinda confused here SOI. What should be the "proper" gauge wire?

[Save Old Iron 1,571]

Jimmy, great question.

 

I think what Marv was asking is there really any reason to listen to folks who - for lack of a better way to put it - brag about using larger size wiring in order to increase the performance of starter circuits or lighting circuits. In the past #4 gauge welding cable was all the rage for starter circuits.

 

This philosophy would be similar to walking into someone's remodeled  basement and have them brag about how they plumbed their water lines in the house with 3 inch PVC instead of 3/4 inch PVC. Okayyyyyyyy. Whyyyyyy ???  Less pressure drop they say. Fills the toilet up faster. Yes, 1/2 second faster and you paid 5 times the $$ amount for the pipe as was needed - but they seem to feel good about what they did so you just snicker to yourself, drink their beer and go home.

 

Would you rewire your house with welding cable, or put 4 inch exhaust pipe on your Honda Civic, or a 1000cfm carb on a 6 cylinder engine cause bigger is ALWAYS better?

 

#6 AWG if fine for stock applications and #8 AWG will be fine for some smaller displacement engines.

 

#4 AWG or larger is overkill in stock applications. There will always be a performance hit in a heavy amp draw system once all the areas that are susceptible to corrosion start to age. Folks who see a performance increase going from #6 cable to #4 cable probably saw the performance change due to going from CORRODED #6 to CLEAN #4 - nothing else. They would have seen the same performance difference going from CORRODED #6 to CLEAN #8 - but then there would not be the ooooh's and awhhh's from the folks who respond better to sexed up myths than boring old math.I will promise to spend some time in the next few weeks finishing off a corrosion and voltage drop tutorial I have been working on and get it posted up here.

 

Now you will have to excuse me. I have to put some STP and Moroso stickers on my car to make it go faster.

[squonk 43,945]

:) I was going to chime in that #6 is fine but I'd know you would have the scientific proof! :thumbs: :)

[Marv 984]

Thanks for the link Old. Just what I needed.

Now a different question. I enjoy your graphic illustrations, How do you produce them?

Marvin

[Save Old Iron 1,571]

Marv,

 

you are welcome for the wire gauge help.

 

The images I use are created in a graphics program called Paint.net

 

Its a freebie with a very large following and excellent support. Check out their site on the web. If you think you want to spend time learning the program, I can certainly provide some assistance to get you started. YouTube is full of paint.net tutorials and several sites are dedicated to Paint.net startup instructions. I would be happy to send you a file or two which would allow you to see how some of my images were created.

[Marv 984]

Thanks Old,

I looked at You tube. Looks to be difficult to learn. Maybe this old man should try just to keep the "mind" active. Will appreciate the files. Maybe it will help me to learn.

Marvin

[KC9KAS 4,744]

 

 

Now you will have to excuse me. I have to put some STP and Moroso stickers on my car to make it go faster.

 

Had a class mate that said he got 15% more horsepower (Barracuda 273 CID) when he painted the rims silver to make chrome reverse wheels!