The more strands the better. Think of it like lanes of traffic. The more lanes the better traffic moves. The multiple thin stands allow more current to move down the path. Thus thicker stands provide more resistance. My first major was electrical engineering, before switching to finance.

By the way, awesome write up! With the step by step pictures, you really can't go wrong!

 

I don't much care for the very high strand counts. It is flexible but wears much easier. The resistance of a 1ga wire over 10-12ft is pointless to argue over if you are using copper. They are essentially the same when talking about this application.

Anyways; heres some math/physics for the nerds
For No. 12 AWG Table 8 of the NEC does list two different DC resistances for
stranded and solid copper.

DC resistance per 1000 feet for solid is 1.93 ohms

For stranded the DC resistance is given as 1.98 ohms per 1000 feet.

So solid should have a slightly higher ampacity.

If we use Table 310.16 of the NEC to determine RCA and substitute into the
Ampere calculation we can find the approximate differences in ampacity.

From Table 310.16 using 75 degrees C as the ambient.

I = 25 amperes, TC = 75 degrees C, and TA = 30 degrees C and RDC = 1.98 ohms
per 1000 feet or 0.00198 ohms per foot.

This converts to 1980 microhms.

From I (in kiloamperes) = SQRT(( TC-TA)/RDC*RCA))

Or

RCA=(TC-TA)/RDC*I*I

Or RCA = (75-30)/1980*0.025*0.025

RCA = 36 thermal ohm feet

For stranded, I = 0.025 kiloamperes from the table

For solid No. 12 copper

I (in kiloamperes) = SQRT ((75-30)/1930*36)

or I = 0.0254 kiloamperes

Then the solid No. 12 copper would have a 0 .4 ampere increase in ampacity.

This is a 0.4/25 *100 or only a 1.6 per cent increase.

Considering that ampacity tables are approximations, this increase in
ampacity does not exceed the error of approximation.

 

Finished product.


Dual 1000CA interestate's with extra starter relay (so I am never without cranking power). These are fairly large and heavy batteries (both together are over 100lbs) so it was a very very tight fit and took pretty heavy duty angle iron to weld them in place. (bolted the angle to the factory bolt locations)

 

Hey ibd where is the factor block to frame ground located?

 

Factor block?

 

Yeah the factory Brock to ground location

 

Lol oh I got you now. I did this to mine a year ago so I might be wrong but mine was the rear of the engine on the passenger side.

 

Thank you!

 

I replied to another thread that this thread was linked in...but to expand the horizon in an attempt to get an answer...

So, I recommended this upgrade on another thread dealing with the 2015 ecoboost, particularly to solve an Auto Start stop issue where the auto start would not engage because it was charging the battery, and another member said that doing this upgrade was a "really bad idea" and to go read about the battery saver function. His only response when I asked further was "did you read the info?" for which I haven't been able find anything since...which is why I asked further (duuuh). Any one know anything about the Battery Saver system and why this is supposedly a "really bad idea" for the Ecoboost?

 

I don't see why it would be a bad idea. All you are really doing is lowering resistance in the wires. As long as you replace the wire exactly as it was then nothing negative will happen. I don't know very much about 12th gens or the battery saver system tho. If there is another wire connected to the stock power wire from the battery to the starter solenoid, as long as you splice that wire into your new one every will be all good.