0, 2 or 4 gauge when relocating battery?
- Thread starter ABOSS
- Start date
Black Knight
I Glow Therefore I am
Re: 0, 2 or 4 gauge when relocating battery?
I used 2/0 cable, but I tend to over do things
I used 2/0 cable, but I tend to over do things
Black Knight
I Glow Therefore I am
Re: 0, 2 or 4 gauge when relocating battery?
:rant: Damn, your right :rant:
It's going to be ripped out of the truck before noon today, your not going to beat me
Where did you get that 200 amp figure?
gjp said:
:rant: Damn, your right :rant:
It's going to be ripped out of the truck before noon today, your not going to beat me
Where did you get that 200 amp figure?
turbodig
Active member
Re: 0, 2 or 4 gauge when relocating battery?
Something to keep in mind...
Due to the low DC resistance of the starter winding, a .5 ohm drop across the length of the cable (including connections) results in a significant voltage drop in the cable.
I wouldn't run any smaller than single-ought. I've seen more problems caused by not enough gauge wire than by too much.
Something to keep in mind...
Due to the low DC resistance of the starter winding, a .5 ohm drop across the length of the cable (including connections) results in a significant voltage drop in the cable.
I wouldn't run any smaller than single-ought. I've seen more problems caused by not enough gauge wire than by too much.
Black Knight
I Glow Therefore I am
Re: 0, 2 or 4 gauge when relocating battery?
And since were not even running much more then 10 ft that drop should be half right or no?
And since were not even running much more then 10 ft that drop should be half right or no?
gjp
another post whore
Re: 0, 2 or 4 gauge when relocating battery?
yeah about half. At 50 amps the 2 wire sizes have almost the same voltage drop. Bigger is always better. Like you said overkill could not hurt in this instance. I have some nice #1 welder cable that I want to use but I am to lazy to change it out. BTW i am using my electricians load calculator.
yeah about half. At 50 amps the 2 wire sizes have almost the same voltage drop. Bigger is always better. Like you said overkill could not hurt in this instance. I have some nice #1 welder cable that I want to use but I am to lazy to change it out. BTW i am using my electricians load calculator.
Black Knight
I Glow Therefore I am
Re: 0, 2 or 4 gauge when relocating battery?
I wish I understood electricity more then just, don't touch it! Amp draw, NEC books, your way over my head. :dunno:
I wish I understood electricity more then just, don't touch it! Amp draw, NEC books, your way over my head. :dunno:
Flyin Ryan
hated cuz he drives fords
Re: 0, 2 or 4 gauge when relocating battery?
so what gauge/cable is idealy the best in this situation?
so what gauge/cable is idealy the best in this situation?
turbodig
Active member
Re: 0, 2 or 4 gauge when relocating battery?
A little resistive divider calculation for ya:
Let's say the DC winding resistance of the starter is 2 ohms. (Pretty close)
Let's say the total resistance of your cable/connections is .2 ohms.
Vout = Vin * starter resistance /(starter resistance + cable resistance)
Using the numbers above, this presents 10.9 volts across the starter.
Lower the cable resistance to .05.... presents 12.2 volts across the starter.
Raise the cable resistance to .8 ohms... presents 9 volts to the starter.
Moral of the story... smaller cables have more ohms per foot. Larger cables have fewer.
Call it overkill, but I've seen a lot of poor-starting rear batteries due to inadequate cable size. Bigger isn't gonna do anything but help.
Downside is that copper is really expensive right now...
A little resistive divider calculation for ya:
Let's say the DC winding resistance of the starter is 2 ohms. (Pretty close)
Let's say the total resistance of your cable/connections is .2 ohms.
Vout = Vin * starter resistance /(starter resistance + cable resistance)
Using the numbers above, this presents 10.9 volts across the starter.
Lower the cable resistance to .05.... presents 12.2 volts across the starter.
Raise the cable resistance to .8 ohms... presents 9 volts to the starter.
Moral of the story... smaller cables have more ohms per foot. Larger cables have fewer.
Call it overkill, but I've seen a lot of poor-starting rear batteries due to inadequate cable size. Bigger isn't gonna do anything but help.
Downside is that copper is really expensive right now...
turbodig
Active member
Re: 0, 2 or 4 gauge when relocating battery?
Yep.
The most notable being how would you terminate it?
Also, I don't know that I've ever seen stranded flexible aluminum cable.
(That is, flexible to the degree you need in an engine compartment... household wiring won't cut it)
mattw said:
Yep.
The most notable being how would you terminate it?
Also, I don't know that I've ever seen stranded flexible aluminum cable.
(That is, flexible to the degree you need in an engine compartment... household wiring won't cut it)
gjp
another post whore
Re: 0, 2 or 4 gauge when relocating battery?
.8 or .2 ohms is verry high. If you have .8 ohs accross the cable you have problems. Unless you are heating it up with high amp draw. A #2 has .12 ohms over 1000feet under no load. while 1/0 has .8 over 1000feet.
Aluminum has high resistance and does not handle heat that well. You would have to run larger wire and risk voltage drop.
For our trucks I would say you can get away with #2. You can use #1 or 1/0 or larger if you wish.
.8 or .2 ohms is verry high. If you have .8 ohs accross the cable you have problems. Unless you are heating it up with high amp draw. A #2 has .12 ohms over 1000feet under no load. while 1/0 has .8 over 1000feet.
Aluminum has high resistance and does not handle heat that well. You would have to run larger wire and risk voltage drop.
For our trucks I would say you can get away with #2. You can use #1 or 1/0 or larger if you wish.