bfdog

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Mirrors are archaic. Time to move on. “TV screens” will allow for significantly better low light/dark visibility, for example, and can completely eliminate the blind spot (though I admit that properly adjusted mirrors also eliminate the blind spot, no one seems to know how to adjust mirrors properly any more.)

I doubt the equally archaic US Government will change its rules in time for the Cybertruck, however, so you’ll probably get your wish for real mirrors.
Do they have cameras yet that can see the blind spot when towing 7 tons behind a vehicle? I was thinking today about a light bar with cameras that telescope out. Super Duty trucks have telescoping mirrors to see the rear corner of the load. Archaic mirrors.
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See, we know that tesla are not the greatest at towing. Although other ICE vehicles are pletty terrible too, but they don’t have range anxiety to deal with. But let’s say that you and your CT were towing a moving trailer that weighed about 8,000 pounds. What if tow mode significantly increased the regen braking, with all that extra weight you could probably make the towing-range a non-issue. Might as well put all that weight to good use.
 

Ehninger1212

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lol i love how musk say it will look "slightly better" :ROFLMAO:
 

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What if tow mode significantly increased the regen braking, with all that extra weight you could probably make the towing-range a non-issue. Might as well put all that weight to good use.
That's not how things work, unfortunately. When you accelerate the tractor and trailer you take electrical energy from the battery and convert some of it to mechanical energy some of which gets converted to kinetic energy and some to potential energy (if going up hill). But an appreciable part gets converted to heat in bearing friction, patch friction, air friction, conversion of DC to AC etc. This latter part is not recoverable. When you take your foot off the pedal the motors become generators and the tractor and trailer slow down and some of the kinetic energy and, if going down hill, potential energy get converted back to mechanical and thence to electrical form which is, in turn, converted to a form where it can be stored in the battery. But not all of it. Some of it gets converted to heat (from electrical and mechanical losses as before). If 90% of electrical energy can be converted to kinetic and potential and 90% of potential and kinetic back to electrical the so called "round trip" efficiency is 81%. Thus regen suffers (optimistically) a 20% loss. When I calculate that the range of a CT pulling a 14,000 lb trailer up a 1 % grade will have a range of about 21% of the EPA range I assume 80% round trip efficiency for regen energy.

There is another factor to consider here and that is that during regen the battery is being charged and there are limitations on how fast one can safely do that. An 8000 lbs trailer being slowed from 70 to 60 mph loses about half a megajoule of kinetic energy. If that deceleration takes 5 seconds (0.05 g) the average power that must be absorbed is about 100 kW. That's more than can be absorbed by the 100 kWh battery in an X today if the battery is cool or at a high SoC. Thus one cannot "increase the regen braking" beyond certain limits out of battery safety considerations. Note that the battery in the TriMotor CT (the only one you would consider for towing an 8000 lb trailer) will probably be at least twice the size of the X's battery meaning that it will be able to absorb more power.
 
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bfdog

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That's not how things work, unfortunately. When you accelerate the tractor and trailer you take electrical energy from the battery and convert some of it to mechanical energy some of which gets converted to kinetic energy and some to potential energy (if going up hill). But an appreciable part gets converted to heat in bearing friction, patch friction, air friction, conversion of DC to AC etc. This latter part is not recoverable. When you take your foot off the pedal the motors become generators and the tractor and trailer slow down and some of the kinetic energy and, if going down hill, potential energy get converted back to mechanical and thence to electrical form which is, in turn, converted to a form where it can be stored in the battery. But not all of it. Some of it gets converted to heat (from electrical and mechanical losses as before). If 90% of electrical energy can be converted to kinetic and potential and 90% of potential and kinetic back to electrical the so called "round trip" efficiency is 81%. Thus regen suffers (optimistically) a 20% loss. When I calculate that the range of a CT pulling a 14,000 lb trailer up a 1 % grade will have a range of about 21% of the EPA range I assume 80% round trip efficiency for regen energy.

There is another factor to consider here and that is that during regen the battery is being charged and there are limitations on how fast one can safely do that. An 8000 lbs trailer being slowed from 70 to 60 mph loses about half a megajoule of kinetic energy. If that deceleration takes 5 seconds (0.05 g) the average power that must be absorbed is about 100 kW. That's more than can be absorbed by the 100 kWh battery in an X today if the battery is cool or at a high SoC. Thus one cannot "increase the regen braking" beyond certain limits out of battery safety considerations. Note that the battery in the TriMotor CT (the only one you would consider for towing an 8000 lb trailer) will probably be at least twice the size of the X's battery meaning that it will be able to absorb more power.
So regen is lossy and regen rate is limited by what a battery can safely receive. What about a launch capacitor and separate launch motor if necessary?
 


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Do they have cameras yet that can see the blind spot when towing 7 tons behind a vehicle? I was thinking today about a light bar with cameras that telescope out. Super Duty trucks have telescoping mirrors to see the rear corner of the load. Archaic mirrors.
This has already been solved by adding a remote camera to the back of the trailer. Between that camera’s view and the two side cameras, the driver’s situational awareness is far better than any you can get from the (yes, very) archaic mirrors.

There is still the “light pollution” from video screens that needs to be solved, but I suspect with OLED or other higher end screen tech, this problem too could be eliminated.

Honestly this discussion seems a lot like the one I’m constantly having with ICE vehicle drivers when they’re trying to convince me that electric vehicles have no future. It’s time to stop thinking up excuses why the new tech won’t work and start thinking up ways we can make the new tech be better than the old, because it can be.
 

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So regen is lossy and regen rate is limited by what a battery can safely receive.
Just don't interpret my remarks as meaning that regen is useless. Far from it. The EPA range of BEVs is fast approaching 400 mi and regen is an appreciable part of being able to get that. Tesla has become more conservative with respect to the temperature at which they limit it and drivers are always trying to figure out how to be sure to have it (heated garages, charging strategies...). Friction brakes are so yesterday!

What about a launch capacitor and separate launch motor if necessary?
A lot of people assumed that Tesla bought Maxwell to get their super capacitors for exactly this purpose and to absorb the relatively brief bursts of energy from regen but as soon as one does the numbers he sees that they aren't an attractive solution as their energy per unit weight and cost is very low compared to a battery. Elon has said that there will be no super capacitors in his vehicles.

As for launch if you are so disposed you can drop a substantial amount of money to get a bigger motor in some of the cars. This enables "Ludicrous Mode". In an X it adds $20K to the cost and knocks a second off the 0 - 60 time.
 

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This has already been solved by adding a remote camera to the back of the trailer. Between that camera’s view and the two side cameras, the driver’s situational awareness is far better than any you can get from the (yes, very) archaic mirrors.

There is still the “light pollution” from video screens that needs to be solved, but I suspect with OLED or other higher end screen tech, this problem too could be eliminated.

Honestly this discussion seems a lot like the one I’m constantly having with ICE vehicle drivers when they’re trying to convince me that electric vehicles have no future. It’s time to stop thinking up excuses why the new tech won’t work and start thinking up ways we can make the new tech be better than the old, because it can be.
My idea (proposed)was cameras that extend a little from the light bar when necessary. Many downsides to that but some upsides. I want to see the load from that angle without wireless and without mounting to a trailer.

As far as comparing my suggestion to an ICE driver saying there is no future for electric cars. haha.. I’m all in on all electric future. I wrote (in 8th grade GT english, not a scholarly piece ha.) a paper on “cars of the future’ as a youngster in 1984 contemplating electric self driving cars as the evolved then future. 36 years ago.? I’ve written 100 patents (for other inventors, never my invention) On some great novel ideas. I have an EE degree. I ordered a Cybertruck. I check this website prolly 1 hour a day because I’m obsessed. Not sure I’m the stubborn ICE guy you run into. But I had a patent case and the patent covered side cameras alone and I tow heavy on the regular. As part of that case I tested side cameras on every car that had them. My truck is hooked up to 14K right now. I’ve self installed upgraded tow mirrors (ten years ago different truck) when the smaller ones weren’t big and safe enough my perspective (fun pun) on cameras versus mirrors could be more informed but it’s far from uninformed or doomsday on EV cars.
 

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This is a CYBER truck. The driver attention sensing camera checks your head movements and points the rear view cameras accordingly!


... the (yes, very) archaic mirrors.

There is still the “light pollution” from video screens that needs to be solved,
The very archaic mirrors have a light pollution problem too. This was originally solved by having two reflective surfaces in the mirror one of which attenuated the reflected light quite a bit. At night one flipped the mirror up or down a couple of degrees with a little tab so that the image came from the attenuative surface. In modern cars day or night is sensed and the reflectivity automatically adjusted accordingly.

In the modern BEV the light level is sensed and the display mode switched to nighttime (goes from white background with dark lettering, map lines etc. to dark background with lighter letters and lines). I never really noticed whether the rear view camera image is dimmed or not as I don't use it while driving.
 

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That's not how things work, unfortunately. When you accelerate the tractor and trailer you take electrical energy from the battery and convert some of it to mechanical energy some of which gets converted to kinetic energy and some to potential energy (if going up hill). But an appreciable part gets converted to heat in bearing friction, patch friction, air friction, conversion of DC to AC etc. This latter part is not recoverable. When you take your foot off the pedal the motors become generators and the tractor and trailer slow down and some of the kinetic energy and, if going down hill, potential energy get converted back to mechanical and thence to electrical form which is, in turn, converted to a form where it can be stored in the battery. But not all of it. Some of it gets converted to heat (from electrical and mechanical losses as before). If 90% of electrical energy can be converted to kinetic and potential and 90% of potential and kinetic back to electrical the so called "round trip" efficiency is 81%. Thus regen suffers (optimistically) a 20% loss. When I calculate that the range of a CT pulling a 14,000 lb trailer up a 1 % grade will have a range of about 21% of the EPA range I assume 80% round trip efficiency for regen energy.

There is another factor to consider here and that is that during regen the battery is being charged and there are limitations on how fast one can safely do that. An 8000 lbs trailer being slowed from 70 to 60 mph loses about half a megajoule of kinetic energy. If that deceleration takes 5 seconds (0.05 g) the average power that must be absorbed is about 100 kW. That's more than can be absorbed by the 100 kWh battery in an X today if the battery is cool or at a high SoC. Thus one cannot "increase the regen braking" beyond certain limits out of battery safety considerations. Note that the battery in the TriMotor CT (the only one you would consider for towing an 8000 lb trailer) will probably be at least twice the size of the X's battery meaning that it will be able to absorb more power.
Good point!
 


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It is the side mirrors that are my concern for light pollution. The rear view mirror can be dimmed but the I have 2 side mirrors that shine in my eyes and I cannot dim these mirrors. The screens can be dimmed to avoid this and only go into the eyes when I look at them. Where I live we can be dark by 5 pm in the winter and not see daylight again until 9 am. We spend a lot of time driving in the dark in winter and I cannot wait to have this solved with side view cameras.
There will be some things to adapt to for driving with side view cameras but I am going to adapt my whole driving experience when I go to an EV, with 1 pedal driving, 0-60 in 2.9 seconds, no behind steering wheel display and all of the other aspects I don’t even know about. What is one more thing to adapt to. Old army saying “Adapt and Overcome.”
Just remember “Change is good Donkey!”
 

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He said slightly better looking. I emphasize slightly in my mind. Metal will be bent the same-guessing. Probably tailgate, front lights, wheel, and wheel well changes.—all slight if any. As far as fancy towing software, he just mentions incorporating the effects of towing on anticipated/calculated performance so you know your range. The fancy software will be active dampening (While towing, auto driving/navigating and ride height controlling downhill in a turn while avoiding sway). But his tweet didn’t say that.
I'm wondering (hoping) if some of those edges/bends could be done with more of a slight radius? That would improve the looks a bit I think.
 

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What about a trailer with additional battery storage to help offset some of the drain on the CT battery. Probably not economical at this point? Just a thought.
 

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Too bad there is no way to tow the CT behind the motorhome, without trailering it. Flat towing would be spectacular!
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