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Aluminum Power Cabling for Model 3 - what does this mean?

Aluminum Power Cabling for Model 3 - what does this mean?

I recently read an article on the Teslarati website - "Austrian cable company [name removed] has secured a large order from Tesla for 3,000 kilometers (1,864 miles) worth of aluminum cabling that will be used to connect the Model 3 electric motor with onboard battery pack.". Does this provide any insight in the engineering of the M3? I'm a physician, not an engineer, but I recall problems with aluminum wiring in homes many years ago. What are the tradeoffs of using Al rather than copper? What's used in the S and X? Either way, I trust that Elon and the engineers have this all figured out. I've got two M3's reserved, hopefully early delivery (#8 in line Dublin,CA on 3/31).

alphacompton | March 24, 2017

To my understanding it's not going to be comprising the electric motor coil. the documentary I saw specifically said that it's half a mile of copper wire that's used to make the electric motor coil.
I'm not sure what the other Tesla's use but at the very least I can extract one piece of useful information for us:

What it means, is that the prototype beta's/release candidates probably haven't been built yet.

KP in NPT | March 24, 2017

This article says the aluminum cable is only going to be used to connect the battery to the electric motor. Not for all the wiring in the car.

https://electrek.co/2017/03/21/tesla-model-3-shielded-aluminum-cable/

Magic 8 Ball | March 24, 2017

Al is fine when used properly. I did an internship at SLAC (Stanford linear accelerator) and they used miles of Al conductor (much was hollow core to allow for coolant to flow through).

topher | March 24, 2017

Al is cheaper than Cu. Al is lighter than Cu. Al requires more metal to carry the same current. Most High voltage long distance electric wires are Al. The issue with Al wires in houses was, IIRC, related to incorrectly making connections to other systems (shouldn't be a problem in a Tesla, unless you fix it (badly) yourself).

Thank You Kindly.

dsvick | March 24, 2017

@alphacompton - "What it means, is that the prototype beta's/release candidates probably haven't been built yet."

No, it doesn't mean that at all. This just means that Tesla settled on a supplier and placed a large order. It doesn't mean that hadn't already ordered a lesser amount for use in the prototypes and release candidates.

brando | March 24, 2017

Some good details about Aluminium vs Copper wires.

http://www.assemblymag.com/articles/88415-wire-processing-aluminum-wire-...

hsadler | March 24, 2017

Yeah, the probs with Al was connecting to another type - such as copper. Ok if done right - but often times it wasn't. Thus the fires.
In this case, however - shouldn't be a factor.

Badbot | March 24, 2017

I have seen alu. wire move from high current flow. alu also fails from flexing much faster that copper.
I hope that some engineer will ask for reconsideration of this choice that saves a few dollars.

samiam | March 24, 2017

The problem with Al is not its ability to carry power. The problem was the poor quality of today's electrical contractors, combined with wood structures. Neither of these factors exist in cars.

Go outside, look up at those high tension power lines. Yep, Aluminum conductors.

Coastal Cruiser. | March 24, 2017

douwe said: "Al is fine when used properly. I did an internship at SLAC (Stanford linear accelerator) and they used miles of Al conductor (much was hollow core to allow for coolant to flow through)."

Hollow core?

To allow coolant to flow through?

Well that sets off a few alarm bells in the "let's reduce costs" department. And not just the lower cost of aluminum. The possibility of double-duty.

First principles thinking, anyone?

kaffine | March 24, 2017

@Coastal_Cruiser The coolant is to keep the cable itself from overheating. I have a welder that runs coolant through the cable. It allows for a much smaller cable that is more flexible and lighter carry the same current. Tesla was using them on some of the SC, I'm not sure if they still are.

Aluminum is being used more and more for building electrical for high current circuits. They made a lot of improvements to the aluminum used and have better connections that can deal with the expansion and contraction of the aluminum due to temp.

Sparky | March 24, 2017

Yes, since the battery system is liquid cooled anyway the addition of cooled cables may be a way to prevent a heat limiting issue in this one section of the power pack. Sounds like good thinking to me and I wouldn't expect anything less.

Bighorn | March 24, 2017

@kaffine
The coolant circulating SC at Mountain View has been removed.

Efontana | March 25, 2017

The cable is short enough that the entire thing can be replaced. Perhaps stir welded copper alloy terminations on each end?

Badbot | March 25, 2017

"Go outside, look up at those high tension power lines. Yep, Aluminum conductors."

the high tension lines were changed to Aluminum for weight savings to allow longer spans between towers.
copper stretches on shorter spans and that is a problem.