Tesla Model 3

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Agree, this is a classic "Chinese Whisper" at best, and at worst...a deliberate click bait.
But, This may be a possible explanation of where the 4416 number got associated with the Model 3
.... apparently this was on a Tesla presentation info Slide recently...
"The Roadster uses 6831 cells" [11S 9S 69P, 18650 form, 53 kWh]
"The Model S uses 5376 cells" [14S 6S 64P, 18650 form, 60 kWh]
"The Model S uses 7104 cells" [16S 6S 74P, 18650 form, 85 kWh, 1520 maxA]
"The Model S uses 8256 cells" [16S 6S 86P, 18650 form, 100 kWh, 1760 maxA]
"The Model 3 uses 4416 cells" [8S 12S? 46P?, 2170[0] form, ~80‒90 kWh derated?]
note.. the reference to "4416" quantity of cells for the M3
unfortunately i cannot confirm this info either ..its from the Tesla Forum ! :| :eek:
 
A larger format battery makes sense to me. The only reason tesla used standardized size cells was that they could source them from multiple manufacturers. Now that they manufacture their own cells a larger format seems reasonable. Especially if you want to make 500,000 cars a year. Fewer cells and modules simplifies the assembly process.
 
Also I remember reading that the model 3 uses a fraction of the wiring of the model s. Which to me points to fewer cells.
 
maydaverave said:
Also I remember reading that the model 3 uses a fraction of the wiring of the model s. Which to me points to fewer cells.
That was mainly a reference to the fact that the M3 wont have all the electronic tricks and gadgets that the S and X have.
For example..the single display panel dash with all touch control for functions.
Tesla have made too many references and details of the "new" cell as a 21700 format, so it cetainly should need less number of cells for any given capacity
If it is 4,416 cells in a M3 pack of about 75 kWh capacity, thats almost half the number the 100S has in its pack.
 
A reduction in wiring in the car doesn't reflect fewer cells in parallel in the traction pack - the pack interconnects are sheet metal, not wire.
 
Punx0r said:
A reduction in wiring in the car doesn't reflect fewer cells in parallel in the traction pack - the pack interconnects are sheet metal, not wire.
It doesn't have balance wires?
 
"The Model Y will be on a different platform than the Model 3. Musk said that the car will be quite different, inside, in part because Tesla is learning how to make cars more efficiently. “The wiring harness on Model S is about 3 kilometers in length,” he said. “The wire harness on Model 3 is 1.5 kilometers in length. The wiring harness on Model Y will be 100 meters. And that’s a redundant wiring harness.” Elon musk
 
spinningmagnets said:
I will bet anyone here one Yankee dollar, that there is no 44160 cylindrical cell coming, from Tesla or anyone else.
I think sizes of this nature are going to come from Tesla in the future. I think the amount of weight in steel cylinders of 21700 cells etc must weigh over a ton for the Tesla Semi truck. I bet the Tesla Semi truck has an annoyingly crap range and they need to drop weight every way they can.
The 18650 is incredibly strong, you can jump up and down on them and they don't deform at all, even AA cells deform but of course, AA cells aren't remotely as volatile.
18650s were designed so that kids could go to sleep safely with their laptops under their beds and companies didn't have to worry about being sued for barbecued kids.
I think the longer Tesla goes without any serious fires the more it will be emboldened to significantly fatter cell sizes, I think even if it just spins the shareholders and pushes up the stock thinking it's going to magically give more performance than its worthwhile Tesla do it even for that reason.
 
Much research was done when selecting to use 21700 size, It's an in house battery being spat off a production line faster than the eye can see.
The reason they went with this size was due to optimise wasted space just have a quick browse on the Web and all the detail are there. With a 21700 you have the most active material while reducing waste space between cells.
We must remember all this sits in a membrane with active cooling so they try to keep the coolant passage with an even flow across it so there's no drops or rises in coolant flowing certain areas with hot or cool spots and with the data they have gathered on 18650 and 21700 it woupd be a retard move to jump ship on their own tech research.
44160 cells are china rubbish I've researched them and they are lifopo4 mostly so to use that woupd be showing major cost saving measures that I wouldn't be happy to buy you will be guinea pigs in a test rig and that's a fact even if it's using 21700.
Notice how the first people to get them are employees to help limit the bad press, it's all a publicity stunt with tesla and he limits his bad rep by actively bribing people into staying quiet if they want thier warrenty to continue I wouldn't buy one not enough ironing out of bugs for my liking.
I noticed 2 toyota mirai passed me today 10 minutes apart not a bad looking car and makes sence in my area local filling station and incentives to buy that's where I would go myself if I had the cash even if hydrogen makes no sence to produce the fact is I have it local dirt cheap compared to uk fuel duty or even charging from superchargers.
 
speedmd said:
44mm diameter x 160mm long, is way too large for Ebike's IMO. If true, this is bad news unless they have some amazing new capabilities.

It's only too big if you assume 48V or more. That wasn't always what we assumed. 7 cells of 44160 would be a little over a kWh, in a very usable voltage range.
 
Ianhill said:
........The reason they went with this size was due to optimise wasted space just have a quick browse on the Web and all the detail are there. With a 21700 you have the most active material while reducing waste space between cells.......
you may want to check the maths on that ! :wink:
 
Large cells have a greater volume to surface area which inhibits their ability to shed heat and so promotes over-heating and reduces discharge capability. It's also difficult to make defect-free large format cells. Bigger is not necessarily better or simpler.

maydaverave said:
Punx0r said:
A reduction in wiring in the car doesn't reflect fewer cells in parallel in the traction pack - the pack interconnects are sheet metal, not wire.
It doesn't have balance wires?

Generally there is only one balance connection per parallel group regardless of whether there is one or a hundred cells in that group.
 
Please Hillhater explain more
Hillhater said:
Ianhill said:
........The reason they went with this size was due to optimise wasted space just have a quick browse on the Web and all the detail are there. With a 21700 you have the most active material while reducing waste space between cells.......
you may want to check the maths on that ! :wink:

I didn't do the math tesla did and they choose the size I just regurgitated the English
From the horses mouth.
Straubel said that Tesla has spent a long time thinking about battery formats, and had questioned why the 18-650 lithium-ion battery had become the standard. Its standardization was “an accident of history,” said Straubel.

Instead, Musk said that Tesla thought about what would be the optimal battery size to produce the product Tesla wants, if no battery standard existed. They say after much consideration they realized that would be the 21-70.

“It really comes from the first principles of physics and economics. That’s the way we try to analyze everything,” said Musk.

It’s also about lowering the overall cost of the Model 3. Tesla has to shave off as much cost from the car as possible—including a planned 30% from the batteries—to be able to meet its goal to make a $35,000 car. It’s other cars currently cost between $70,000 to $120,000.

Changing the size of a battery can have trade-offs. For example, if you make a lithium-ion battery bigger, it could store more energy and produce more power. However, longer and wider batteries could mean that the battery pack (which collects individual battery cells together) could be wider or heavier, which could constrain design or range of the car.

Not everything scales well and they have many reasons to pick the 21700 to many for this thread and considering I only get snubbed with no real answers that's as far detail I'm willing to go considering I said do a quick simple search and you clearly didn't.
 
Ianhill said:
Hillhater said:
Ianhill said:
........The reason they went with this size was due to optimise wasted space just have a quick browse on the Web and all the detail are there. With a 21700 you have the most active material while reducing waste space between cells.......
you may want to check the maths on that ! :wink:

I didn't do the math tesla did and they choose the size I just regurgitated the English
From the horses mouth.

I think his point is that packing uniform sized cylinders wastes the same percentage of space no matter the size of the cylinders.

It's true that for a given amount of protection from the canister, making cells bigger allows them to have a larger ratio of reactive chemicals to overall volume. That's what I was observing about the hypothetical 44160 cell.
 
The whole "44160" speculation was the result of a misunderstanding by a journalist. Why did Tesla choose the 21700 over the already-existing 26650 cell? The answer is heat dissipation.

Tesla and Panasonic have invested a HUGE amount of money to come up with the 21700 cell, and now there is speculation that a 44160 may have been better? (*SMH). The reason they didn't go with a larger cell is that a physically larger cell would have a worse time shedding heat from its core. Tesla has an 8-year warranty on their battery pack, and they have no control over if a few of their customers are idiots. In very cold weather, the Tesla pack is warmed, and in hot weather...it is cooled. If a larger cell would have performed better, they would have made the 44160-format the cell of choice for the Model-3...
 
^^^^ but, if they could make the cells with a higher C rate (lower IR,) then the warming/cooling issue would not be a consideration.
EG ..the way Nissan went with their latest packs.
..I. Suspect the real reason Tesla opted for the cylindical format is speed of production and proven production technology.
It is just a natural progressive step on from the 18650 processes , thus minimising the manufacturing learning curve.
But then as you say, size is limited by the other considerations such as heat dispersion, and manufacturing equipment capacity.
 
Hillhater said:
^^^^ but, if they could make the cells with a higher C rate (lower IR,) then the warming/cooling issue would not be a consideration.
EG ..the way Nissan went with their latest packs.
..I. Suspect the real reason Tesla opted for the cylindical format is speed of production and proven production technology.
It is just a natural progressive step on from the 18650 processes , thus minimising the manufacturing learning curve.
But then as you say, size is limited by the other considerations such as heat dispersion, and manufacturing equipment capacity.
Exactly with the tech they had on offer the 21700 was many jigsaw pieces that completed their battery puzzle but like you say it's not the end all and be all theres no reason they can't expand in size a little with tech improvments but for what they wanted at the time its their new standard in cylindrical cells.

Pouch cells cool in a much better fashion than cylinder cells so we can not compare apples and oranges both have thier merits over each other the 21700 is rugged enough to perform well over time and so do the leaf cells but for kwh per kg the tesla cells are ahead but Nissan is dropping new battery tech that will double range so they say so we can only hear the dribble and make sence of it in the real world when it arrives.
 
Hillhater said:
^^^^ but, if they could make the cells with a higher C rate (lower IR,) then the warming/cooling issue would not be a consideration.
EG ..the way Nissan went with their latest packs.
..I. Suspect the real reason Tesla opted for the cylindical format is speed of production and proven production technology.
It is just a natural progressive step on from the 18650 processes , thus minimising the manufacturing learning curve.
But then as you say, size is limited by the other considerations such as heat dispersion, and manufacturing equipment capacity.
It seems what is better for performance is not as good for range and cycle life. ....
 
All I know is I have a couple old motorcycles collecting dust waiting for batteries to catch up on simplicity to motors and controllers. 44160 seemed like a great size for diy motorcycles oh well. in a year or so we will hopefully be up to our eyeballs in recovered model 3 cells. Any idea of model 3 module size, voltage, ah?
 
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