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redpoint5 09-20-2020 01:32 PM

Tesla Battery Day Thread
Link to Tesla Battery Day Livestream. It follows the investor meeting which begins at 4:30pm EST, 1:30pm PST.

Tesla battery day is Sept, 22. Figured we could have a thread to speculate on what will be revealed.

Some speculate an announcement to supply batteries to other manufacturers, some speculate a $100 per kWh pack price will be announced, or a million mile battery.

What do you expect?

RedDevil 09-20-2020 02:22 PM

There are a couple of things that are almost certain, because of the patents that Tesla filed for in the last couple of years; tabless cells, simplified pack construction with cells immersed in coolant (rather than having coolant channels weave betwee the cell rows like now), new electrolyte additives that vastly increase the number of cycles, etc.

There are photo's of cells presumably made by Tesla themselves at the Kato Road facility in Fremont. And they are huge; over 7 times the capacity of Model 3 cells, over 10 times the Model S cells.

All of that is impressive and none of it will blow anyone's mind - and that's the very thing Musk promised Battery day will do.
So I don't really know what to expect and am just patiently waiting to have my mind blown. We'll see.

Meanwhile I have been investing in TSLA. On a small scale; just 5 shares I bought at the slump last year. Those raised like a Falcon 9 and split in 5.
I sold a few to have my original investment back so what happens next is all bonus.

I also noticed the stock is quite volatile. It can easily jump or dive 10% or more in a single day of trading.
I decided to make use of that volatility by adopting a strategy where my shares are to represent a certain amount of money; say $8000. If it rises and I can sell a share while the remainder is still above $8000 I will do so. If it drops and I can buy and still be below $8000 again I'll do so.

Now every time I sell a share it is the very one I bought cheaper earlier on, and vice versa. With every round trip I make about 5% of that share's value, and I have about 10 transactions per week so go figure; I should be able to add one share every month.

My mechanism brings extra yields when the stock jumps or dives hard. Then suddenly it trades way beyond what my buy or sell trigger would be and I can trade a couple at way bigger margins than usual.

Which brings me back to Battery Day. I will stretch the buy/sell limits a bit because I expect fluctuations will be wild. Time to take profit!

oil pan 4 09-20-2020 07:36 PM

It would make more sense to use toilet paper roll sized cells.

RedDevil 09-21-2020 04:43 AM

Actually, the idea behind using many small cells instead of a few big ones stems from the unreliability of lithium-ion cells.

Over time and use dendrites form between the cathode and anode and when they meet the cell shorts and dies. If you have a battery with big cells in series that will reduce the voltage of that pack if it is able to bridge that cell, or kill it entirely if it isn't.

Whereas the Tesla approach has 40+ small cells in parallel with a thin lead to each cell which acts as a fuse. If a cell fails it will get out of line with the other cells in its tier, draw more current and blow its fuse. It is then isolated and the tier remains at 98% of its original capacity. Even if dozens of cells fail distributed over the pack the total capacity only drops significantly if many of those happen to be in the same tier; usually the failures will be randomly spread over the pack and no tiers will have more than a pair or so. The pack is much more robust.

Advances in production technique have made lithium cells more reliable over time, so now it is no longer essential to split the pack into small cells. The Model 3 and Y already use bigger cells than the S and X and their packs seem much more robust nonetheless.

redpoint5 09-21-2020 11:37 AM

That, and larger cells have less surface area per volume, meaning it's more difficult to regulate their internal temperature.

I always wondered the same thing in the silicon wafer industry. We made 6", 8" and 12" wafers with larger ones in the works. My question always was why they didn't just determine the optimal diameter from the outset and start with that. It's not that easy.

RedDevil 09-21-2020 05:56 PM

The larger cells are supposed to have a lower internal resistance, which reduces their dependency on coolant - annihilating the negative effect their size would have.

freebeard 09-21-2020 07:52 PM


Meanwhile I have been investing in TSLA.
How do you do that? I've told Arcimoto if I could walk into their office and trade cash for shares I'd do it. Do you use a broker, or is it all in the cloud?


What do you expect?
The speculation I saw [citation needed] has the foil layers rolled up and stuffed in a can. [The whole can is electrode?] That's the tabless part. The ganged cans are clamped to a top plate with the wiring. It's flooded with coolant.*

The advantage with the bigger cells includes 1/10th the parts that need assembly.

There may be additional financial or chemistry announcements. One step closer to Mars.

*What would be really cool is if the can, the coolant, and their container all constitute a supercapacitor. :thumbup:

Hersbird 09-21-2020 10:11 PM

All I know is I have to reserve a new Xbox tomorrow. Batteries not included... Actually I bet it has two crappy AA's for the controller.

redpoint5 09-22-2020 12:21 AM

I'd be inclined toward PlayStation 5 primarily because of Gran Turismo 7. The new controller sounds neat too. Close call though because I enjoy Halo.

I may never own another console again. No time to game, and when I finally do get time in the future, everything will be cloud hosted.

RedDevil 09-22-2020 05:08 AM


Originally Posted by freebeard (Post 631559)

Originally Posted by RedDevil (Post 631498)
Meanwhile I have been investing in TSLA.

How do you do that? I've told Arcimoto if I could walk into their office and trade cash for shares I'd do it. Do you use a broker, or is it all in the cloud?

I first used the trade options in the online portal of my bank (ING). But after the stock split and I expected many transactions per week the cost there ($4 per trade + 0.25% of the share price) became prohibitive.
So I found an online broker (Degiro, aimed at the Dutch market) which only asks about $0.50 per trade.

I still hold the remainder of my stock at ING - the sleeping part that I will not likely touch. Degiro has the shares I am willing to trade with. If that broker was to fail I might lose that (even though there are warranties to protect the clients, but you never know); the ING-held shares are as safe as the bank - or safer still.

Of course if you want to invest you have to find a broker that suits your own needs. Here is a starting point and here's Arcimoto's stock (FUV).
I don't know whether investing in TSLA is wise right now. A year ago it definitely was since it went up 10 times in a year. But it is almost guaranteed to be quite active with lots of swings so you might plan to generate money from that tidal motion, like I do.
Likewise Arcimoto shot up 5 times since March.

Yesterday TSLA opened around $445, then spiked down to $408 and went up again to $449. I automatically bought one share at $416 and sold it again at $436, a $19 profit after transaction costs.
All the time my stock remains worth just above $8,000.

The stock movement in the coming few days will be interesting.

hayden55 09-22-2020 09:24 AM


Originally Posted by RedDevil (Post 631498)
Photo's of cells presumably made by Tesla themselves at the Kato Road facility in Fremont. And they are huge; over 7 times the capacity of Model 3 cells, over 10 times the Model S cells.

Time to take profit!

So its official that we have the 69420 cells finally.

I will say the larger size will be a good thing. The current cells are just too small for the assembly process. It takes so long to assemble them that the majority of the pack price is labor on most assembly or disassembly projects with these cylindrical lithium batteries.

RedDevil 09-22-2020 10:37 AM

It is not official yet. Even if the cells are legit the size may be different after all as afaik it is still just a guess; you cannot measure from those photos.

Musk lifted a tip of the veil:

We intend to increase, not reduce battery cell purchases from Panasonic, LG & CATL (possibly other partners too). However, even with our cell suppliers going at maximum speed, we still foresee significant shortages in 2022 & beyond unless we also take action ourselves
The mind-blowing may well involve production numbers beyond anyone's expectation?
China, Germany and Texas are large enough to produce over half a million cars per year each, so... to blow minds it must be more than that even?

@freebeard: I just put a limit order on 20 FUV. It needs to drop a bit to execute, so it may not materialize; but I like the Arcimoto even though I'll probably never own one.

MetroMPG 09-22-2020 11:32 AM

Subscribed for the informed chatter. I have no horse in this race, but Elon is interesting.

freebeard 09-22-2020 01:39 PM

redpoint5 09-22-2020 02:12 PM

It can be reliably assumed that any announcement from Tesla will result in a 2 year target date, with likely delays pushing that back even further.

On the tangent topic of battery constraints ultimately limiting EV sales volume, there was an interesting TED talk that proposed PHEV as a better use of limited battery production capability. Rather than build 1 EV that can go 400 miles on a charge with a 100 kWh battery, make 10 PHEVs that can go 40 miles on a charge. The idea is that although some trips would exceed the EV range, 85% of the miles could be accomplished in EV mode. This strategy maximizes the scarce battery resources by bringing utilizing more of the capacity in each vehicle, and minimizing the cost by not equipping the vehicle with more battery than is typically needed.

Assuming 12,000 miles per year, a single 100 kWh EV would drive 12,000 EV miles. If that battery were distributed across 10 PHEVs which drive 85% of miles in EV mode, that would be 102,000 miles, or 8.5x more.

The current focus on EV production is misguided, especially given the current federal tax credit rules which would allow manufacturers to maximize the incentive with a minimally sized battery. Not only would it be more environmentally friendly to focus on PHEVs, but it would be the smarter financial move in the short-term.

RedDevil 09-22-2020 02:17 PM

One thing to expect: battery costs are going down substantially. Not just the new cells but all cells.
The cost of the stationary 232 kWh PowerPack battery has just come down from $170,000 to $125,000 hours before Battery Day...

jakobnev 09-22-2020 02:24 PM

1. Million mile battery.
2. 400 wh/kg.

3. 1 & 2 two years from now.

freebeard 09-22-2020 02:50 PM


2. 400 wh/kg.
Minimum for Electric VTOL

oil pan 4 09-22-2020 04:31 PM

I thought the claimed to already be making million mile batteries?

redpoint5 09-22-2020 04:44 PM

Tesla live stream is on now:

freebeard 09-22-2020 04:46 PM

2020 Annual Shareholder Meeting and Battery Day

Live as of posting. Introductory comments now, meeting before Elon.

Not enough time in my day today.

edit; off by 2 minutes.

Welp, I guess we have to solve r*cism and s*xism before we can get to how to get the cobalt out. Foist things foist.

2nd edit: Tesla drive-in movie theater! :thumbup:

3rd edit: When it comes to sustainable energy, Mr. Musk is an accelerationist. I guess that explains Ludicrous Speed.

oil pan 4 09-22-2020 05:21 PM

The funniest part about cobalt is at least 90% of the BEV fan boys are blissfully unaware as to its implications in slavery, child labor, horrifying environmental damage.
I guess they're not gong to care about it until someone tells them to.

RedDevil 09-22-2020 05:30 PM

Battery day will be about batteries "and a few goodies" Musk said just a minute ago (IIRC)... I like goodies!

freebeard 09-22-2020 05:35 PM


The funniest part about cobalt....
The last two proposals in the board meeting show the Marxist-feminists realize if the cobalt and nickel are taken out they lose a leverage fulcrum. Oh, the Iron-y.

edit: They're back....

running edit:
  • Tabless or all-tab?
  • Elon mesmerized by a bottling plant movie :)
  • factories running at Ludicrous Speed.
  • cruelty-free cathodes.
  • casting ALchemy.
  • stressed-skin battery packs lighten the rest of the car.
  • $25K car. That's two FUVs.

RedDevil 09-22-2020 06:01 PM

Wha... the Kato Road facility produces at the rate of 10 GWh per year???
That's 30% of Giga Nevada at less than 5% of the size!

RedDevil 09-22-2020 06:26 PM

Mining lithium by extracting it using table salt... !!!

RedDevil 09-22-2020 06:43 PM

Plaid Model S 0-60 <2s; 200mph; standing mile <9s... Yup, mind blown!

RedDevil 09-22-2020 06:49 PM

Way past midnight... signing off. I'll see the rest tomorrow.

freebeard 09-22-2020 07:23 PM

Aaand.... it's complete.

I think this should be shown in every classroom in the country, maybe with the Q&A for extra credit.

One mind-blowing thing after another. Raw silicon anode? Raw nickel cathode? Future Miners of America?

redpoint5 09-22-2020 07:36 PM

I could have done without the low information SJW complaints with no solutions offered during the investors meeting.

Interesting to hear Musk say the environmental science is not settled, and that his main motivation for Tesla was to address standard of living and scarcity issues for humanity.


Originally Posted by oil pan 4 (Post 631621)
The funniest part about cobalt is at least 90% of the BEV fan boys are blissfully unaware as to its implications in slavery, child labor, horrifying environmental damage.
I guess they're not gong to care about it until someone tells them to.

That's the main folly of this country, and by proxy, "white people". We seem to think everyone else's problem is ours to solve, and to dictate how others should live.

It's a good thing there isn't some vastly advanced nation that sees the US as backwards, and therefore cut trade with us since we're all slaving away.

That's not to say injury and certain child labor isn't terrible, only that I'm not going to impose my personal "minimum wage" sensibilities on others. Is a tough job worse than no job? Should the US be invading "The People's Republic of Congo" in an effort to liberate them from corruption?

We know when a country is terrible when it includes any of the following words; People's, Democratic, Republic. Maybe Dominican Republic is an exception.

freebeard 09-22-2020 07:42 PM

Yeah, I thought he dodged the 'Califonia is brown' framing pretty well.

I've already moved on. Building a DIY Transparent Hybrid Rocket Engine - NightHawkInLight

Well, I was making a salad and I found myself chuckling over "The Board recommends against this proposal. You have three minutes."

We'll announce the result after we show what we've been working on for years.

redpoint5 09-22-2020 07:52 PM


Originally Posted by freebeard (Post 631632)
I've already moved on.

I'm saving up for a CyberTruck, and by saving up, I mean constantly dropping hints to my wife how all our problems would be solved by it. :P

There's probably a 15% chance I'll get one, but it's still fun to think about.

freebeard 09-22-2020 08:03 PM

Storing up social credit. :thumbup:

Sad that we won't get the compact travel-size Eurotruck here. Maybe an El Camino/Ranchero/Rabbit/Rampage version of the $25K affordable car? I'd bet it will be stainless steel, because why not?

RedDevil 09-23-2020 03:35 AM

Batteries, factories. Tesla was production limited by battery supply during its entire life, and probably still. Even if they had them the factories were production limited; Fremont cannot be expanded further.
So it did not make sense to offer a variety of models because it would not increase sales in total.

Now that several Gigafactories are being built at once and battery production gets ramped up big time, there will be more room to expand the model range and build not one but several sizes of Cybertruck. Give it a couple of years.

oil pan 4 09-23-2020 08:55 AM

Maybe they should invent a better way to lithium brine.

hayden55 09-23-2020 09:44 AM


Originally Posted by RedDevil (Post 631593)
It is not official yet. Even if the cells are legit the size may be different after all as afaik it is still just a guess; you cannot measure from those photos.


Nah that was more of an elon joke off Twitter about battery size.

oil pan 4 09-23-2020 11:17 AM

I'm down.

TexasCotton 09-23-2020 01:08 PM

Tesla Shanghi Elon Battery CATL China CCP
FYI ... Tesla Shanghi China CCP brutal atheist evil to the core regime forced labor live human organ harvesting mass killing of internal population genocide manipulation and subjugation of world resources and economies. Tesla, Apple, GM, Ford, FCA, Germany, and politicians and wall street sold out to this regime and have blood money on their hands. Elon Musk wants fast and cheap and ChinaCCP delivers force labor. 7 day work weeks and personal daily quota otherwise longer work day or punishment.

oil pan 4 09-23-2020 02:01 PM

Yeah slavery gets stuff done.

jakobnev 09-23-2020 02:38 PM

1 Attachment(s)
I found this to be a bit meh:

More interesting was the tabless battery which promises tremendous power density and ability to fast charge faster than ever before without more degradation than today's batteries have with slow charging.

Also other improvements in both chemistry and production process.

And structural batteries, if the promises are true, then effective pack energy density will be higher than for naked cells, something previously thought to be impossible.

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