Investor Engineering Discussions

[SwTslaGrl]

Perhaps someone's interested in this event tomorrow,

COMSOL Day: Batteries & Fuel Cells
Modeling batteries, fuel cells, and electrolyzers for transport mobility
March 24, 2022 10:00 a.m.–4:00 p.m. CET

Learn How to Use COMSOL Multiphysics® in a Guided Session

Learn how to use the COMSOL Multiphysics® software at a guided training course, webinar, or COMSOL Day. Find an onsite event near you or watch online.

www.comsol.com

 

[JRP3]

Center screen is setup to articulate, seems to only be missing the motors.

Now that I have my Model 3 I really wish it had this feature, even if it were just manually adjustable. I like to have my seat back relatively far which means I need to lean forward to reach the screen. I might try one of the aftermarket kits at some point.

 

[Buckminster]

This electric motorbike uses metal origami to improve sustainability
Cyber bike tech

 

[JRP3]

Claimed faster charging speed, high cycle life, and reasonable energy density, supposedly applicable to existing manufacturing lines.

Technology - Battery Streak | Charge Lightning Fast

Battery Streak nanostructured technology allows lithium ion batteries to charge at up to 15C with high energy density, low heat and high capacity retention.

batterystreak.com

 

[CorneliusXX]

Claimed faster charging speed, high cycle life, and reasonable energy density, supposedly applicable to existing manufacturing lines.

Technology - Battery Streak | Charge Lightning Fast

Battery Streak nanostructured technology allows lithium ion batteries to charge at up to 15C with high energy density, low heat and high capacity retention.

batterystreak.com

That tech sounds super interesting (albeit with the same large grain of salt that all battery tech announcements deserve). If it works it sounds like it should be compatible with Tesla's manufacturing tech - just a electrode material change.

 

[JRP3]

A few months ago I was looking into Niobium and Lithium Titanate that Toshiba has been using to improve their Scib LiTiO chemsitry and talked to Jordan/Limiting Factor about digging into it further.

Toshiba Clip | Toshiba’s Lithium-Ion Batteries – driving the future of a decarbonized society (Part 3)

When we talk about addressing global warming and reducing CO2 emissions, electric automobiles and hybrid cars come to mind. But have you ever delved deeper to see how they’re powered? The batteries need to be safe, reliable and provide high input and output power. Toshiba’s SCiBTM rechargeable...

www.toshiba-clip.com

 

[Doggydogworld]

A few months ago I was looking into Niobium and Lithium Titanate that Toshiba has been using to improve their Scib LiTiO chemsitry and talked to Jordan/Limiting Factor about digging into it further.

Toshiba Clip | Toshiba’s Lithium-Ion Batteries – driving the future of a decarbonized society (Part 3)

When we talk about addressing global warming and reducing CO2 emissions, electric automobiles and hybrid cars come to mind. But have you ever delved deeper to see how they’re powered? The batteries need to be safe, reliable and provide high input and output power. Toshiba’s SCiBTM rechargeable...

www.toshiba-clip.com

Toshiba's LTO SCiB cells are pretty amazing in terms of cycle life and charging speed, but never took off commercially due to high cost and low energy density. I had high hopes when they announced higher-density NTO back in 2017, but nothing seems to have come from it. I'm very skeptical of Battery Streak, but would love to see a Limiting Factor episode on Niobium chemistries.

 

[mongo]

I tried, but they blew the power to it I think. Last known location was a flashback from the scene when it came to rest.
Rust in Peas little Peddler.

@Ogre
I believe the car blows the pack pyrofuse when the airbags deploy.

 

[Ogre]

@Ogre
I believe the car blows the pack pyrofuse when the airbags deploy.

Makes a ton of sense. So conceivably there might not be any pack level damage or shorts and the fuse could be replaced. Saw the explosive fuses on the Model S. Not necessarily an easy/ cheap fix, but possible.

 

[SOULPEDL]

@Ogre
I believe the car blows the pack pyrofuse when the airbags deploy.

However, not right away, the screen was still active several minutes afterward.
But think I briefly saw a message like "10, 9, 8 ,7, engaging Suspended Animation, please remove your belongings from the glove box."

 

[mongo]

Makes a ton of sense. So conceivably there might not be any pack level damage or shorts and the fuse could be replaced. Saw the explosive fuses on the Model S. Not necessarily an easy/ cheap fix, but possible.

Pack pyro fuse is easily accessible with an external access cover. Pretty simple swap, if you have the part.

However, not right away, the screen was still active several minutes afterward.
But think I briefly saw a message like "10, 9, 8 ,7, engaging Suspended Animation, please remove your belongings from the glove box."

Interior electronics run off the 12V system which can stay up for a short time (depends on battery type) with the main pack offline.

 

[SOULPEDL]

Ya this is a better thread, so check this design out. Weight of the car holds the wheel in place on impact to absorb some of the energy into bending the axle.
This is safety design on steroids, I can only assume. Lower profile tires might also matter for reduced tire roll action. Ha! I can finally justify bigger wheels.

 

[SOULPEDL]

Pack pyro fuse is easily accessible with an external access cover. Pretty simple swap, if you have the part.

Interior electronics run off the 12V system which can stay up for a short time (depends on battery type) with the main pack offline.

Cool, so I just put in a Mobile Service request in the App and it was accepted. (I'm having way too much fun with this.)

 

[Ogre]

Cool, so I just put in a Mobile Service request in the App and it was accepted. (I'm having way too much fun with this.)

Sure, they can fix it in your driveway. LOL

 

[mongo]

Sure, they can fix it in your driveway. LOL

Yah, it'll buff right out.
Seriously though @SOULPEDL, they would likely require a full inspection before reenabling the HV system. Both the inspection and pyro replacement require a lift, so it's outside the range of what mobile service will do.

 

[mongo]

I don't see how this would improve work-flow, but I'm not an Engineer.

Tesla's GA lines are already the shortest in the World, with about 40 stations compared to around 100 at VW/Toyota et.al.

Musings regarding one long GA line vs two parallel short GA lines:
Tesla has been linearizing part flow with the spung structures being the peak of trailer to line path minimization. This works great for a single line, but if you add a second parallel line then you need all the second line's parts to cross to the first. I think Tesla tried a conveyor system to do this which failed (and became the core of the hail mary sprung GA line). If you can feed parts from both sides, this problem is reduced, but then you need two sided semi access and more trailers.
Using a long single line allows the loading dock to installation flow to stay short with twice as much landing zone. This also means a lower density of trailers allowing for easier allocation and up time (one spot active, one empty/ swapping).
It also reduces factory complexity by only having one destination for sub assemblies like doors.
Of course, this does still require double the line side equipment for process steps that take longer than the max takt time and cannot be further sub divided. This a the weakness of the long line setup, for example, if pack to chassis marriage takes too long then two stations are needed. However, this could be handled by a split and rejoin setup. On the flip side, fast processes need not be duplicated.
One line also removes any conveyer redundancy, should it be needed.

 

[MP3Mike]

"Join the Cell Team" page doesn't show any cooling tubes. This clip came from Battery Day.

View attachment 771257

Tesla showed another slide with "cooling channels" below the cells.
View attachment 771272

Finally, the problem with fat cylinders is getting the heat through all the layers to the sidewalls. The tabless design directly moves heat from each layer down to the bottom of the cell via the thermally conductive copper. Other companies, e.g. Rivian, say this thermal path is more efficient even without the tabless design.

Jordan's structural pack video spells out the bottom plate cooling approach in more detail.

Well I think we can put this to rest now. New video out of GigaTexas shows that the packs are still sort of made of, or at least assembled from, modules, and they clearly have cooling ribbons between the cells:

It looks like just three "modules", but this is probably for the new Model Y Standard AWD with ~280 miles of range. (Another video shows the screen in a GigaTexas made car as a "Standard Dual Motor" with range that calculates to 279.)

 

[mongo]

While it likely can be cooling tubes, you can't put cells from one parallel string to cells from another string as canister is negative terminal point of cell and you would create dead short if put them together without insulator

Every cooling tube has an insulator sleeve on the outside. It goes:
Cell
Tube w separator
Separator
CTCSCTCSCTC
Adjacent cells have gap on all sides. Large gaps are likely for BMS system, plus increase distance between higher potential sections (voltage difference).

 

[nativewolf]

So how do the engineering folks here view the 4680 to date? Some posters in other threads seem to think that the performance did not meet expectations, listed EPA range below what was expected, etc. That Tesla was avoiding discussing details on Y austin deliveries talking about future hype instead.

 

[mongo]

So how do the engineering folks here view the 4680 to date? Some posters in other threads seem to think that the performance did not meet expectations, listed EPA range below what was expected, etc. That Tesla was avoiding discussing details on Y austin deliveries talking about future hype instead.

4680 is great, but they need more of them. Standard range allows more vehicles to be built which improves margins by distributing fixed costs across more units.