He used to be a huge TSLA bull, but I think he sold all his shares just before it took off end 2019, then he went full Q
Sold all his shares right before the 2019 run up? OUCH, that must have HURT!!!!
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He used to be a huge TSLA bull, but I think he sold all his shares just before it took off end 2019, then he went full Q
I believe Elon recently stated that he gets a lot, if not most, of his work done while in the air. Hopefully he gets some sleep up there as well.Macron visited Biden Thursday, so likely still in the US. But still impressive schedule for Elon.
I believe Elon recently stated that he gets a lot, if not most, of his work done while in the air. Hopefully he gets some sleep up there as well.
Retrofit new cameras with existing connectors, is feasible. Additional cameras require a new wiring harness, which IMO is far less feasible.
I always thought lucid was a scam but Rivian has no excuse. Neat suv but an f is generous, all they had to do is copy most of what Tesla didWhy? I feel like the only thing these new ev companies copied from Tesla is how to hype. The real meat is how to make a profitable car which happens during the design phase AND the production line. I feel like both Lucid and Rivian skipped those classes when they were learning from Tesla. The Chinese however didn't sleep during those classes
-300% gross margin is a F - and should go back to the drawing board.
I can't imagine that Tesla engineers would not have either considered a case of limited regen or ensured that there's always spare capacity since this is safety critical and safety is always on top of Tesla's priorities.Resistor banks are also used in some wind and hydro applications. But they are problematic. Hence my wondering what Tesla's plans for that situation are - beyond the obvious ones.
I can confirm he has Starlink. Now, the bed is only about the size of a queen bedHe has a large bed on the plane.
I believe someone also reported his plane is a mobile Starlink beta site as well.
I like the clutch implenentation, elegant.
I'm interested in how they will handle the use case where a fully laden and fully charged truck starts descending a long hill. Where will they put the regenned energy, or will they become brake-limited (primarily by thermal management constraints). Before anyone yells at me that such situations don't exist there are plenty of them around the world.
And just to finish the story: in a circuit, current flows into the vehicle on one conductor and back out of the vehicle on on the other conductor. So, if it’s 1.6 kW on one wire in the cable, it’s another 1.6 kW on the other wire.I imagine you are keeping it simple (since you are an EE) but people here like the full story. Resistance for the wire sizes they use (and they are using fine strand so it is lower than what I have posted... less skinning effect) is PER 1000" of wire. The cable to vehicle is less than 20'. That means the resistance will be what... 50 times less than what's on the chart. I would imagine the high voltage lines up to the charge stand will be typical full size.
1000*1000* .08 / 50, or 1.6KW
I am going back in hiding now.
When you get to your final bullet point you probably have a few seconds of useful braking life left, if that. The lighter and more efficient the motor - and the 3/Plaid is a doozy - the shorter the time, as the thermal mass reduces proportionately to the physical mass. This rapid termination is because the neos reach their Curie temperature. From then on you lose magnetic torque and the only route out then is:You keep the axles engaged and use the motors to brake. Multiple regimes, something like
* Normal Regen
* Normal Regen + friction brakes
* Inefficient Regen (starts producing more heat and less electricity)
* Inefficient Regen + friction brakes
* Inefficient Regen + friction brakes + thermal management (as the motors get hot you spend energy to cool them)
* Really inefficient Regen + friction brakes + thermal management (at this point your regen is not sending power to the main pack but it's not pulling from the main pack)
* Negative regen + friction brakes + thermal management (now you are pulling power from the pack and generating more heat)
You've got 3 motors so the amount of braking force they can provide is large. They don't have to put power back into the packs to brake. In fact they can brake harder if they pull power from a full pack.
When you get to your final bullet point you probably have a few seconds of useful braking life left, if that.
I wasn't assuming any particular length of time in any regime and my experience is that this can all happen much faster than people appreciate, but your point is a fair one. At any stage the truck can indeed say "I'm Sorry Dave, I'm Afraid I Can't Do That".You are assuming the same amount of time in each regime / too long a time in the wrong regime.
The system can jump straight to the bottom of the list if needed. Mapping data, cameras, inertial sensors, motor speed, vehicle speed, etcetera is enough data for the vehicle to choose the right mode almost immediately.
Not going to be positive ever. Tesla can make 2500 roadsters with a positive margin. The Model S had a positive margin during the ramping phase. It's grueling to hit profitability by having the gm high enough and operating leverage high enough to overcome operating expenses to have a positive operating margin. Lucid and Rivian are no where close.
The product must start with a positive margin in this car industry or else it's game over before you even started. Musk knew this, other companies seem to not understand.
We already know that they can accelerate a full load going uphill with engines only and no friction brakes.I wasn't assuming any particular length of time in any regime and my experience is that this can all happen much faster than people appreciate, but your point is a fair one. At any stage the truck can indeed say "I'm Sorry Dave, I'm Afraid I Can't Do That".
It'll be interesting to see if Tesla have found another way that hasn't previously been considered.
And just to finish the story: in a circuit, current flows into the vehicle on one conductor and back out of the vehicle on on the other conductor. So, if it’s 1.6 kW on one wire in the cable, it’s another 1.6 kW on the other wire.
Reminds of the three laws of thermodynamics: You can’t win, you can’t break even, and you’re stuck in the game .
I wasn't assuming any particular length of time in any regime and my experience is that this can all happen much faster than people appreciate, but your point is a fair one. At any stage the truck can indeed say "I'm Sorry Dave, I'm Afraid I Can't Do That".
It'll be interesting to see if Tesla have found another way that hasn't previously been considered.
We already know that they can accelerate a full load going uphill with engines only and no friction brakes.
While regen for the purpose of recharging the pack is less than 100% efficient, braking and just converting it to heat is not.
So if they can use 3 motors to do more than counteract gravity going uphill on the steepest route they could find, then they can use 3 motors to counteract gravity going downhill. AND they have friction brakes on top of that.
I'm not sure what problem you think they need to solve.
Resistor banks are also widely used in diesel-electric train locomotives with very few problems that I'm aware of. Seems like a good idea to me. I would think it much simpler and less taxing than putting large amounts of heat energy into the powertrain/heat pumps.Resistor banks are also used in some wind and hydro applications. But they are problematic. Hence my wondering what Tesla's plans for that situation are - beyond the obvious ones.
If the aim is to bring the vehicle to a halt, and thereby eliminate the source of heat, then provided it is done early enough then @dhanson865 is quite correct.I think petit_bateau's point is that reversing the motors to actively brake, instead of regen, would generate significantly more heat (and much more quickly) than anticipated.
So I think we should look at it this way:
How much power (in KW) does it take to go uphill at a constant speed? That should be the same power (in the form of heat) that you'd need to dissipate going downhill. As long as the motors + cooling system can convert that to heat and dissipate it out into the air, then there's plenty of "braking" capacity to go downhill, even without regen.