Alternator Wire Sizing

[rleng1]

Need to extend charging wire from alternator to the kill switch. Run will be about 6'. Anyone ideas on what gauge wire I should use, and what size is the stock wire?
thanks,
Randy

[marshall_mosty]

I did overkill and ran 2-guage. I'm runningo 1-0 welding cable for the battery...

[rleng1]

Thanks Marshall. The current wire looks to be 8 gauge. I was going to run 6 gauge. Length is more like 12'.
Any issues?

[mitchntx]

http://www.rbeelectronics.com/wtable.htm

I think the standard alternator on an LSx car is 90A max.

12V
100A
15'
#6

12V
50A
15'
#10

The load on your alternator with a hot battery is WAY below 50A.

[rleng1]

Thanks Mitch. I was thinking that the alternator was less than 100A. Since it is 50A, and from the table you attached, I should be fine with the 6 ga. wire.

[BryanL]

Perfect timing English and great info Mitch. Before I saw this post I was going to make a post paging "Dr. Volt".

Anyway, I found my car this weekend and it was still in the trailer just as dirty as I left it from ECR. I started having charging issues at Hallet. Changed the alternator and still the same thing at ECR. Took the alt. to be checked but their connectors were messed up so they gave me a different one. Same story, it would charge at about 13 volts. The battery also wasn't holding a charge so I thought that could be an issue, too.

Using the battery charger as a voltmeter I was only getting 13 volts at the battery. Then 13.2 at the kill switch. Then, got 14 when on the back post of the alternator. But I have a real small wire running from the alternator to the kill switch.
I thought it should put out 14.7?

So, my plan is to replace the battery and wire to hopefully take care of my problem. Otherwise I'll be paging Dr. Volt this weekend.

[GlennCMC70]

make sure to rev the motor some as the output will vary some depending on the RPM the alt is at.

[GlennCMC70]

Also, each cell of the battery is 2.2 volts per cell (w/ there being 6 cells in a car battery). So as long as you are delivering more than that to the battery, it will charge. 2.3 volts per cell is a good float voltage.

[BryanL]

So I am finally getting around to adding a bigger charging wire from my alternator to my cutoff switch.
Do I need to run a resistor or a small light bulb in between the alternator and cutoff switch to prevent damaging my alternator?

[rleng1]

BL, glad you liked my timing....it was a year ago to the day. Just now catching up. need to focus on racing.
I ended running 6 ga. from alternator to kill switch. Battery charges at ~ 13.7v when cold, but seems to reduce to ~13v when it gets hot. Louis suggested that I replace the alternator with original alternator.