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First Model 3 Battery Teardown!

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Sandy Munro of Munro & Associates tore down the Model 3's battery pack. He said that it is extremely well built and years ahead of anyone else in the industry.

That starts at 28:21 into the video. I recommend watching the whole thing (on 2x speed on youtube), lots of new information and insights.

Interestingly, I can't tell how the pack is cooled from the pictures.

  • The battery is balanced +/- 0.2mA between "blocks"
  • "I don't think you're going to get a bad battery cell"
  • The battery pack is potted with some kind of compound
  • "Oh my God, look at this"
  • "I don't know how they put it together"
  • "Look at the power density"
  • "We started finding all this "magic stuff""
  • "This won't be going out any time soon (in reference to the pack)"
  • "Anybody who ignores this car does so at their own peril"

 
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They were not all negative. And probably had some useful critiques for Tesla. Some things they didn't understand why Tesla built it the way they did. Maybe Tesla had a reason, or maybe not and it's something that could be improved.

I thought is very fair and fully researched with facts. Most car manufacturers do this as part of product development. It takes time but well worth the investment.
 
Sandy Munro of Munro & Associates tore down the Model 3's battery pack. He said that it is extremely well built and years ahead of anyone else in the industry.

That starts at 28:21 into the video. I recommend watching the whole thing (on 2x speed on youtube), lots of new information and insights.

Interestingly, I can't tell how the pack is cooled from the pictures.

  • The battery is balanced +/- 0.2mA between "blocks"
  • "I don't think you're going to get a bad battery cell"
  • The battery pack is potted with some kind of compound
  • "Oh my God, look at this"
  • "I don't know how they put it together"
  • "Look at the power density"
  • "We started finding all this "magic stuff""
  • "This won't be going out any time soon (in reference to the pack)"
  • "Anybody who ignores this car does so at their own peril"

One reason I want a Model 3 is because of that battery. However, I wonder if it can be produced profitably. There may be a reason other manufacturers have less sophisticated designs. The I-Pace cooling loop is between the battery floor pan and the cells. It looks like it is easily positioned during assembly. The Tesla cooling loop is a hollow ribbon contoured to fit snuggly between the cells and may be more difficult to install. If you look at the battery photo carefully, you will see a thin wire runs from the top of each cell to the bus bar. If there are five thousand cells in the battery, that is 10,000 high quality welds that have to be made (the cell number is a guess). Those wires are designed to melt and isolate an overheated cell. A great design but a complex assembly step. Elon acknowledged that battery assembly had been a bottle neck.

My take on Sandy Munro's emphasis on the suspension design was not that it is a remarkable feat of engineering but that it is in a car at the Model 3 price point. It is a very good suspension but one you would normally find on a much more expensive car. If Model 3 profit margins are too thin, the company's future is in jeopardy. Tesla had to scrap automation already paid for and bring in hourly workers. That will raise cost and slow production as evidenced by the need to add a third shift. This has to significantly increase cost and lower profits. I love Tesla and hope it makes it but TSLA is the most shorted stock in the country right now. I hope the shorts are wrong but I would not count on their positions being baseless.
 
A bunch of uninformed people commenting on report of a badly informed expert whose time has passed.

What is all the obsession with untrained people on the assembly lines?
Will those people still be untrained at job 10.000? Job 50.000? Job 100.000?

What is with 'I don't understand why they did this or that'?
He is supposed to be an expert who understands.This is what he is selling. Who is buying his 'I do not understand'?

There was zero insights on Teslas room to change the design and process.
Are those problems here to stay because reasons? Will tesla be able to improve?
Remember those 20 design changes per week during Model S ramp?

There were things in his talk that anyone with a slight tesla insight can understand is BS. He does not know who makes the board? He wants to scan those microchips with xRay to see what's inside?

This is an expert? He is a good sign of the state of general auto industry.... a bunch of old farts cemented in old ways.

I'm not interested in where Tesla is, I can mostly see that. I wanna no where Tesla can go, will go, is going. That is the future. I could not care less how good was assembly doing the job no. 890... irrelevant trivia.
 
A bunch of uninformed people commenting on report of a badly informed expert whose time has passed.

What is all the obsession with untrained people on the assembly lines?
Will those people still be untrained at job 10.000? Job 50.000? Job 100.000?

What is with 'I don't understand why they did this or that'?
He is supposed to be an expert who understands.This is what he is selling. Who is buying his 'I do not understand'?

There was zero insights on Teslas room to change the design and process.
Are those problems here to stay because reasons? Will tesla be able to improve?
Remember those 20 design changes per week during Model S ramp?

There were things in his talk that anyone with a slight tesla insight can understand is BS. He does not know who makes the board? He wants to scan those microchips with xRay to see what's inside?

This is an expert? He is a good sign of the state of general auto industry.... a bunch of old farts cemented in old ways.

I'm not interested in where Tesla is, I can mostly see that. I wanna no where Tesla can go, will go, is going. That is the future. I could not care less how good was assembly doing the job no. 890... irrelevant trivia.

That old fart knows how to help the auto industry make money and improve product. His comments about not knowing why they did certain things is because all other car companies would do it better. Tesla may have the tech part right but there is a whole lot more to building a value mass produced car at a profit. In an industry where pennies make a difference you can not have such a poor design and be competitive.
 
So they have opened an i3 and volt, makes him an expert to comment on battery design and architecture, compared to design engineers who have worked their whole lives on this subject?

This guys wouldn't know a thing to point out the main flaw in Nissan's Leaf battery architecture if he opened one.

Not him but they do employee battery experts who actually did the teardown and produced the engineering reports.
 
One reason I want a Model 3 is because of that battery. However, I wonder if it can be produced profitably. There may be a reason other manufacturers have less sophisticated designs. The I-Pace cooling loop is between the battery floor pan and the cells. It looks like it is easily positioned during assembly. The Tesla cooling loop is a hollow ribbon contoured to fit snuggly between the cells and may be more difficult to install. If you look at the battery photo carefully, you will see a thin wire runs from the top of each cell to the bus bar. If there are five thousand cells in the battery, that is 10,000 high quality welds that have to be made (the cell number is a guess). Those wires are designed to melt and isolate an overheated cell. A great design but a complex assembly step. Elon acknowledged that battery assembly had been a bottle neck.

That is the same system used to cool/ heat the S/X packs. Thermal transfer is much better through the sides of the cells than the bottom in terms of available area and thermal path. Assembly wise, they may premount the cells to the tube (the bandolier referenced in other articles), then fold them into the module shape. Fast, linear operation.

Regarding the bond wires themselves, they protect cell/pack from over current/ shorted cells, not a particular temperature. The same type of attachment is done on S/X packs and is much simpler to do than these welds used in in semiconductor industry: Wirebond Technology Rolls On
For reference, an Intel i7 processor can have over two thousand bond wires per chip (3,600 for Xeon).
Interesting to see that they are connecting both wires at the top end vs top and bottom on the S/X. Explains why the connecting plates are so convoluted. Also means lower profile and single sided bonding machine.
 
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There were things in his talk that anyone with a slight tesla insight can understand is BS. He does not know who makes the board? He wants to scan those microchips with xRay to see what's inside?

This is an expert? He is a good sign of the state of general auto industry.... a bunch of old farts cemented in old ways.
Do you have experience R/E'ing circuit boards? I do.
The way you do it right is to 3D Xray them, exactly like Sandy said.

-Jim
 
One reason I want a Model 3 is because of that battery. However, I wonder if it can be produced profitably. There may be a reason other manufacturers have less sophisticated designs. The I-Pace cooling loop is between the battery floor pan and the cells. It looks like it is easily positioned during assembly. The Tesla cooling loop is a hollow ribbon contoured to fit snuggly between the cells and may be more difficult to install. If you look at the battery photo carefully, you will see a thin wire runs from the top of each cell to the bus bar. If there are five thousand cells in the battery, that is 10,000 high quality welds that have to be made (the cell number is a guess). Those wires are designed to melt and isolate an overheated cell. A great design but a complex assembly step. Elon acknowledged that battery assembly had been a bottle neck.

My take on Sandy Munro's emphasis on the suspension design was not that it is a remarkable feat of engineering but that it is in a car at the Model 3 price point. It is a very good suspension but one you would normally find on a much more expensive car. If Model 3 profit margins are too thin, the company's future is in jeopardy. Tesla had to scrap automation already paid for and bring in hourly workers. That will raise cost and slow production as evidenced by the need to add a third shift. This has to significantly increase cost and lower profits. I love Tesla and hope it makes it but TSLA is the most shorted stock in the country right now. I hope the shorts are wrong but I would not count on their positions being baseless.

I could be mistaken but I believe that the Model 3 battery pack assembly is largely automated, and that some of the automation steps weren't working well, which was one of the early bottlenecks.

The new battery automation equipment prototyped in Germany and shipped to Nevada was supposed to clear this bottleneck.

On the other hand we know that Elon regrets how heavily they relied on automation for the Model 3 assembly so perhaps this is also an area that required more human involvement.

Battery seems like an area that would benefit from automation greatly though, just like PCB assembly is not done by people at soldering workstations for the last 15-20 years.
 
So ... more manual work will enable tighter tolerances and less variation in build quality?
This is what I don't understand? This is what Sandy is telling us?

What Tesla skipped is the part where they crush first 2000 peaces from the line because of the problems Sandy was talking about.

What Sandy skipped is the part that people learn, assembly line gets tuned and Tesla constantly optimizes the design.
What Sandy does not understand is that Tesla does not do model years, it does not sit on design changes waiting next September.

Same story with Roadster, same story with S, same story with X, same story with 3.