Tesla, TSLA & the Investment World: the Perpetual Investors' Roundtable

[2daMoon]

An 80k lb Semi coming down a 7% grade at 65 mph needs about 730 kw in braking power (net continuous) to perform that descent without increasing its speed.

There are a few 7 mile stretches like that on certain highways (although many are much shorter). But call it a max of 7 minutes giving a total of 78.5 kwh of energy, at a regen rate of 730 kw.

That's very close to a 1.2C charge rate (well within bty specs) on a 300 Mile range Semi (assuming a 600 kwh bty). Semi will consume about 15 kw of that regen power, the rest will go to charging the bty and charging losses / heat.

So it'll be fine. Easy, peasy, lemon-squeezy.

BTW, this is why big diesel trucks have to slow down on steep descents. Their engine (jake) brakes can not absorb that much braking energy, so they slow down to decrease the potential energy absorbed per unit of time. Of course, friction brakes are overwhelmed by heat in just a few 10s of seconds.

Now, who wants to know how fast a Semi with a 1 MWh bty pack can come down that mountain w/o overheating its battery pack? Any guesses?

Cheers!

Maybe this can help provide any missing details for your calculations ...

Just trying to be helpful. It is Sunday after all.

 

[Tes La Ferrari]

An 80k lb Semi coming down a 7% grade at 65 mph needs about 730 kw in braking power (net continuous) to perform that descent without increasing its speed.

GM is a serious threat to Tesla in this area because Mary could "lead" and "change the game" again by licensing the "gravity power technology" from Nikola as they have been rolling "emissions free" semis down the hill for far longer than anyone in the business.

We better watch out.

 

[dhanson865]

Now, who wants to know how fast a Semi with a 1 MWh bty pack can come down that mountain w/o overheating its battery pack? Any guesses?

Cheers!

Do we know the ambient tempature, battery pack temperature, inverter temperature, and coolant loop temperature at start (and what too hot for each are?) or are we working with spherical cows?

 

[SOULPEDL]

My Tar line is fixed. It’s turning left so it’s off center only to show the line clearly in this frame. Very shiny but not fooled. This is improving fairly quickly.

 

[insaneoctane]

Yes on the regen. A four-motor Semi taking an 80,000lb load down a Colorado mountainside at 65mph will generate a LOT of kW. The 4680's will be able to take this power load without heating up too much.

And - as any Tesla owner will attest, regenerative braking makes you a safer driver because you tend to keep more distance behind the vehicle in front, so that you can exploit regen as much as possible. Will be nice for semi drivers to start driving that way

More 4680 thoughts... it's worth noting the comment from an anonymous Tesla employee that was circulated here recently. (I wish I could find it and link to it) The quote was something like "4680 will be game-changer due to the tabless design, which allows for much faster charging." Tabless design/faster charging was the top-billed advantage that the employee mentioned. If we look at the charging curve of the 18650-based Plaid Model S that was published in Car And Driver, it can hold at 250kW for five minutes. If the 4680-based cars can hold 250kW for ten minutes, that gets you a significant number of miles added in just 10 minutes, and brings the optics of "a realistic ten-minute charge" into view. If a faster Supercharging standard is introduced, as Elon announced at the Cybertruck reveal (it'll be capable of more than 250 kilowatts, we'll reveal the actual number later"), ten minutes would get you even more range, and/or you could depart sooner.

I think the 4680 is the battery generation which will "kill" the gasoline refilling time advantage. There may still be a difference; but it's lost in the noise of "how fast do you get out of your car" / "are you wiping the bugs off the windshield" / "are you going into the store to get snacks" / "are you messing around with luggage in the trunk while you fill up" etc.

I personally believe that the tabless 4680 battery offers significantly less internal resistance, less heat generation and heat soak, better cooling features and, therefore, will charge better than any battery yet. I also think Tesla would have these important features included as they clean-sheet their future battery design. My hunch is due to Osborne concerns, the superior charge capability of the 4680 is being excluded from conversations for now. I don't know that they'll charge as fast as ICE pumps gasoline, but I'm expecting higher regen rates, higher discharge rates, and higher charge rates (and/or longer sustainably at these rates). We'll know more when Tesla decides to tell us, but everything I've seen indicates that things will be better to much better with tabless 4680s

 

[kanweg]

It ~depends~. But let's do some calculations, cuz it's Sunday and it's fun.

50 cents per mile is cheap, 750 dollars is expensive.

Say you get one of those swanky Model 3's or Y's, say 55K for a car you like and taxes paid. Now, the second hand car market is weird so it's kind of a guess what the value would be after 2 years. Say you land on 35K after 2 years post-covid times. That's 10K a year. Say you do 10K miles a year, that averages on a dollar per mile of cost, excluding charging.

Change the values to get different results, but you'd need to get 45K back after 2 years/20K miles to be break-even to a robotaxi, and that's excluding insurance and charging costs.

Truth be told, that Brit would be better off taking the high speed rail to the south of France and get a robotaxi there. Chances are that'd be cheaper. Taking an airplane would be even cheaper, but that's cheating cuz there is no VAT on airplane tickets.

Well, at issue was the range of a cheap car, so with say $25-30k, which changes the calculation. And in my country, most private people drive even in this category cars as second hand cars. (I’m oldish and I’ve never had a new car in my life. Ironically it will be Musk that will make owning a new car possible in the future.)

Rail capacity is insufficient for a summer mass exodus and for the sake of CO2 we don’t want the plane as the most attractive alternative.

 

[Buckminster]

You all need to promise me that you will give me a virtual punch if I ever show signs of losing my fanboi energy:

https://twitter.com/x/status/1470085145050951692

 

[ZachF]

Gigafactory Finland?

https://twitter.com/x/status/1470121297891971072

 

[Thekiwi]

You will all enjoy this:

Stuff

i.stuff.co.nz

Local policy maker who wants to go green but for some reason doesn’t like EVs encounters obvious problem after buying a hydrogen SUV

 

[jerry33]

Do we know the ambient tempature, battery pack temperature, inverter temperature, and coolant loop temperature at start (and what too hot for each are?) or are we working with spherical cows?

I always heard it was spherical chickens of a uniform density.

 

[Thekiwi]

Gigafactory Finland?

https://twitter.com/x/status/1470121297891971072

I think more likely giggity in Finland for Elon.

 

[wws]

GM is a serious threat to Tesla in this area because Mary could "lead" and "change the game" again by licensing the "gravity power technology" from Nikola as they have been rolling "emissions free" semis down the hill for far longer than anyone in the business.

We better watch out.

So this brings up something interesting. Supposedly H2 makes more sense in big trucks than pure EV. But if you were headed downhill from Donner Pass (or Wolf Creek Pass - take your pick) with a 80K lb load, can an H2 powered truck do much regen? They have relatively small battery packs compared to full EV. And no ICE, so no Jake Brake...

 

[Ogre]

You all need to promise me that you will give me a virtual punch if I ever show signs of losing my fanboi energy:

https://twitter.com/x/status/1470085145050951692

Isn’t this the guy who did a comparison between then Cybertruck, Rivian, and F-150 and spent the whole episode talking about how the truck looks and what the interior was like?

Then concluded the Cybertruck was primarily for Nerds who love Bladerunner or something stupid like that… ??

Doesn’t have to worry about me getting on his channel.

 

[ZachF]

You all need to promise me that you will give me a virtual punch if I ever show signs of losing my fanboi energy:

https://twitter.com/x/status/1470085145050951692

I stopped watching Ben a long while ago… Not really for any Tesla views I might potentially agree or disagree with, but because he knows almost nothing about cars, driving, basic electrical or mechanical engineering, physics, and investing (iirc he only really “gets” software) and his constantly observable ignorance on these subjects got in the way of enjoying any of his videos.

Honestly him not knowing basic sh..stuff about cars was the most obnoxious part of a car channel.

 

[Beltsbear]

You all need to promise me that you will give me a virtual punch if I ever show signs of losing my fanboi energy:

https://twitter.com/x/status/1470085145050951692

It worked for me. I was a sub nine Months ago, and he made it clear, he had an ax to grind with Tesla, and if you did not agree, don’t let the door hit you on the way out.

he is basically a male “Karen” When it comes to Tesla.

 

[StealthP3D]

It ~depends~. But let's do some calculations, cuz it's Sunday and it's fun.

50 cents per mile is cheap, 750 dollars is expensive.

Say you get one of those swanky Model 3's or Y's, say 55K for a car you like and taxes paid. Now, the second hand car market is weird so it's kind of a guess what the value would be after 2 years. Say you land on 35K after 2 years post-covid times. That's 10K a year. Say you do 10K miles a year, that averages on a dollar per mile of cost, excluding charging.

Change the values to get different results, but you'd need to get 45K back after 2 years/20K miles to be break-even to a robotaxi, and that's excluding insurance and charging costs.

Truth be told, that Brit would be better off taking the high speed rail to the south of France and get a robotaxi there. Chances are that'd be cheaper. Taking an airplane would be even cheaper, but that's cheating cuz there is no VAT on airplane tickets.

It's true the value after 2 years is uncertain, same with any car. But we can make an educated guess and and losing over 36% of its value with only 2 years and 20K miles is pessimistic in the extreme for a Tesla Model 3 or Model Y, COVID or not. It's unrealistic. Perhaps an ICE car would lose that much, or more, since EV's are disrupting ICE sales, but one must remember, manufacturers cannot hope to fill all EV demand in only 2 years' time so prices will almost certainly stay much higher than your projection. This is one of the big economic advantages of buying an EV at this time instead of ICE.

Disruption is not called "disruption" without good reason! These are not normal times and 'professional' residual value estimators are going to be made fools of time and time again through this disruption. It will cause finance companies to go bankrupt and larger firms to take big write-downs. It's going to be painful for those who rely on "professional advise".

 

[ZsoZso]

Looks like the government of Canada has joined Elon in opposing the proposed US EV incentive program:

While their logic maybe sound in theory, I see one major practical flaw: as far as I know* there is not a single EV being produced in Canada and sold in US, which would be treated "unfairly" by the incentive program. On the other hand, if Canada introduces tariffs on US made EVs in retaliation, that extra cost will obviously get passed onto the customers who buy them, so effectively, our "smart" government decided to punish its own citizens who wanted to buy US EVs in order to protect nobody -- since no actual Canadian interest was harmed by the US incentive! Huh ?!?!

That has gotta be the stupidest knee-jerk reaction I've ever seen by a government...

*: please let me know what EV is being made in Canada in case there is any I do not know about

 

[StealthP3D]

I stopped watching Ben a long while ago… Not really for any Tesla views I might potentially agree or disagree with, but because he knows almost nothing about cars, driving, basic electrical or mechanical engineering, physics, and investing (iirc he only really “gets” software) and his constantly observable ignorance on these subjects got in the way of enjoying any of his videos.

Honestly him not knowing basic sh..stuff about cars was the most obnoxious part of a car channel.

Ben Sullivan gets so much wrong, so consistently, it would be funny if not for the fact that he takes himself so seriously. It's sad what happened to big Tesla fans who sold out far too soon, thinking they did well. I believe his expertise is in statistical analysis but to be good at statistical analysis requires a feel for the subject you are analyzing so he often fails there too.

 

[SPadival]

You all need to promise me that you will give me a virtual punch if I ever show signs of losing my fanboi energy:

https://twitter.com/x/status/1470085145050951692

Ben used to say on his channel that he doesn't trust the stock market - hence he doesn't buy individual stock and instead buys index funds (I don't understand that logic).

Thank god for that.. he must be bitter after missing out

 

[redan]

Elon in a good mood tonight.

https://twitter.com/x/status/1470157804304572420