Tesla Battery Investor Day

[Artful Dodger]

Not convinced the Cybertruck will be the catalyst for the new cells / modules. Also, $50k Cybertruck won't have 200 kWh.

There's no signs of any plans to produce more volume of the current 2170 cells:

• no new construction underway at GF1/Sparks
• Model Y production timetable indicated 10K packs / wk at Fremont
• GF3/Shanghai to use locally sourced 2170s from 3rd parties

All Tesla's known or planned capacity for bty cells and packs is already allocated.

So how does Tesla get to 500K/yr (10K/wk) production on Cybertruck without a new source of battery cells?

 

[SwTslaGrl]

Perhaps of interest,

Does the Current Flow Backwards Inside a Battery? | COMSOL Blog

"Concluding Remarks on Electric Current Flow Inside Batteries
Although this discussion may sound trivial, understanding the above principles is probably one of the most important requirements for a conceptual understanding of electrochemistry. It takes some reading and hands-on modeling and simulation work to acquire this understanding. No wonder my teacher at school had problems explaining this concept!"

 

[Artful Dodger]

The subjects of bty supply and new products are inextricably linked. Let's recall Elon's words from the "Ride the Lightning" podcast, episode 200, published on June 2, 2019 (from ~ time index 57:30)

"I think the Semi will be a very big part of Tesla's business, as well the pickup truck.

"They are very important fundamental use cases. We've got to have at least one of what we think is an amazing product in all of the key use cases.

"So, full-sized sedan, full-sized SUV, mid-sized sedan, mid-sized SUV, pickup truck, and Semi for commercial trucking. These are very fundamental.

"But it only makes sense to add new cars at volume if we have the battery cell capacity to support them.

"Otherwise we're simply adding complexity but we're not putting more vehicles on the road."​

So my inference is that Tesla would not be introducing a new vehicle (Cybertruck), which increases complexity for Tesla's manufacturing, unless they had a sufficient supply of additional battery cells to produce the new vehicle at volume.

More recently (Q3 Earnings Call), Elon referred to a vehicle entering volume production as when at least 1,000 vehicles per week are being produced (50K/yr). So even if we take two low end estimates (50K trucks/yr * 100kwh/truck) we have established a MINIMUM additional bty cell requirement of 5 Gwh per year.

However I highly doubt Tesla's production plans are for this minimun amount. The Pickup market is roughly equivalent to the mid-sized SUV market. Elon has previously stated he thinks Model Y's market is over 1M units per year, 750K in a recession.

I also don't think Cybertruck will be particularly useful with only a 100 kwh bty pack. I think the avg pack will be closer to double that size. So Telsa must be contemplating plans to produce at least 100 to 200 Gwh / yr of bty cells for its pickup entry alone.

Keep in mind, Elon also mentions the intent to build out capacity for 20M cars/yr. If their pickup product is only 1M units, that's just 5% of planned capacity.

These numbers get big, fast. But that's what its going to take to finally put an end to the ICE age. Let's roll.

Cheers!

 

[JRP3]

Modules can be added or removed from vehicle or home.

This doesn't seem likely, and why would it even be desirable when the truck will already have AC output on board? Not to mention the extra engineering involved and balancing issues created by a removable module. I think you went off the rails with this one.

 

[Artful Dodger]

This doesn't seem likely, and why would it even be desirable when the truck will already have AC output on board? Not to mention the extra engineering involved and balancing issues created by a removable module. I think you went off the rails with this one.

Its desirable to not have hundreds of kwh's of battery storage capacity sitting idle for 95+% of the time (RV hauler or weekend warrior use case), when that capacity could pull double duty during the week buffering power from a solar roof or the grid.

We already know that Cybertruck will output AC power, likely 220v at sufficient amps to run commercial power tools. If the AC output is at the module level, then its trivial to link modules at different SOCs in parrallel.

Back on the rails.

Cheers!

 

[JRP3]

If the AC output is at the module level,

Why would it be? And why would you even try to engineer removable modules which weigh hundreds of pounds, (Model 3 pack architecture), with high voltage connections and cooling connections, in a sealed protected case, when using the whole pack would provide more power with less stress and no balancing issues? The whole concept is a bit insane, rails nowhere to be found

 

[mongo]

FWIW, the Powerpack has battery modules with individual DC-DC converters to handle charge/ discharge.

 

[Rockster]

Maxwell would need to be sitting on a never before heard of miracle breakthrough for caps to make any sense in a passenger vehicle battery pack. There might be a use in heavy limited range vehicles with a lot of stop and go, like a garbage truck.

Could they replace the 12v batter with a supercap? That would eliminate an ownership pain point.

 

[JRP3]

Yes, but no. Part of the issue with the 12V battery is it relies on the DC/DC converter to keep it charged. Caps have higher levels of self discharge and large voltage swings when supplying power, which means the DC/DC would have to work even harder and possibly fail more often. Vampire drain would be higher. You'd also need a physically large cap bank to provide some reserve power between the cycling of the DC/DC. Much better, as in most situations requiring energy storage and frequent cycling, would be to use Lithium Titanate battery chemistry. High cycle life, high discharge/recharge capability, much better energy density than caps, and less temperature sensitive than other lithium ion chemistries. LiFePO4 and NMC might also work, not sure if modern formulations have fully solved cold weather charging for them.

 

[Artful Dodger]

Why would it be? And why would you even try to engineer removable modules which weigh hundreds of pounds, (Model 3 pack architecture), with high voltage connections and cooling connections, in a sealed protected case, when using the whole pack would provide more power with less stress and no balancing issues? The whole concept is a bit insane, rails nowhere to be found

Bah, this is discussion is going down the drain. You said adding or removing modules won't work because the could be at unbalanced voltages. I said that's easy to fix by putting the AC output at the module level rather than the pack level. Then you replied why would it be?

To get to the other side, obviously. K, bye.

 

[JRP3]

Bah, this is discussion is going down the drain. You said adding or removing modules won't work because the could be at unbalanced voltages. I said that's easy to fix by putting the AC output at the module level rather than the pack level. Then you replied why would it be?

Yes, in other words, why go to the added cost and complexity of putting the AC output at the module level when that limits the potential output for the pack? Plus individual AC output doesn't address the unbalanced modules with different use patterns going back into the pack. Especially when coupled with the other issues I pointed out. It's just a bad idea across the board, not worth your effort to try and defend it.

 

[Buckminster]

I feel bad for Goodenough; he's been destroying his reputation these past couple years. This should have been the peak of his life, getting the Nobel Prize for his pioneering li-ion work. Instead he's wrapped up in what's widely considered to be bad experimental design with Braga.

My forecast odds for battery day, being announced for availability with their first-generation of internal production:

• Lower production costs: 100%
• Dry manufacturing: 97%
• At least slightly longer lifespans: 95% (Model 3-style pack rated for an average >300k mi)
• At least moderately longer lifespans: 50% (Model 3-style pack rated for >= 500k mi)
• Dramatically longer lifespans: 30% ("million mile battery")
• At least slightly higher energy densities: 85% (<10% gain)
• At least moderately higher energy densities: 50% (10-30% gain)
• Dramatically higher energy densities: 25% (>30% gain)
• Lower-cobalt: 70%
• Cobalt-free: 25%
• Lithium metal anodes: 20%
• Solid state, loose definition of the term: 8%
• Solid state, strict definition of the term: 4%
• Air cathodes or other dramatic departures: 2%
• Intent to introduce ultracapacitors to EVs: <1%
• Working with Goodenough: 0%

 

[Kmartyn]

Are they still targeting March, for Battery investment day? Would be good to have the good news out there before the end of the first quarter. Should help the stock price.

 

[Brando]

Elon has talked (Third Row Tesla interview) how modules are not needed and it makes sense to just have battery packs (no modules).
There was a design idea (like GM claims they are doing??) if you make all modules identical, you can easily swap them. Time has proven no real need to do that.

Seems that [car - home storage - home solar/wind - grid connections] the design norm for now.

Different chemistries for different uses still seems likely ??
Pack life keeps improving - recycle [packs vs raw materials] I think still an open and changing question.
2013 + 8 = 2021 is the first "batch" of out of warranty packs. And many will have only 100,000 miles (12,500/year) of use, right?
2012 was <2000 vehicles, right?

Can hardly wait for 4/20 day.

 

[JRP3]

If they have achieved a higher density NMC or similar long cycle life chemistry there may be no reason to use different chemistry for different applications.

 

[ZeApelido]

Is it actually on 4/20? Source?

 

[JRP3]

I don't think any official date has been given, and considering current events even if it had been it would probably change.

 

[Buckminster]

Battery day now split from powertrains day. Moved to May most likely.

Bullish that Elon has enough content for two separate events.

 

[TheTalkingMule]

Don't we already have a Battery Investor Day thread?

 

[Buckminster]

From the main thread:

Thanks I must admit this patent threw me at first, because I was wondering how it would combine with Maxwell.
There is an art in writing patents, making claims as wide as possible, while revealing as little as possible.

I remember there was some talk about whether milling in the Maxwell process could deliver "something like" single crystal, you don't need "something like" when you have the real deal.

The complete shopping list of battery Investor Day is:-

• Cobalt Free - Dahn
• Single Crystal - Dahn
• Some Silicon ? - SilIon?
• Dry Electrode - Maxwell
• Million Mile Electrolyte - Dahn
• Larger Form Factor? - Tesla / Maxwell
• Cell-to-Pack? - Tesla
• Improved Cooling? - Tesla
• Fast low capex addition of capacity - Maxwell/Hibar/Grohman/Tesla

Given that Elon's mind has been blown, I'm optimistic we will get a fair chunk of the shopping list...

Special credit must go to the Dahn team for working out what problems were important, and solving 3 very important problems in what seems to me like a shorter than normal time-frame...

Roll on Battery Day, I'm like a kid waiting for Christmas ....

Cheers.