Tesla packaged trailer upgrade kit

[Newton]

This makes me wonder if FSD will be able to work with a trailer

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[Crissa]

This makes me wonder if FSD will be able to work with a trailer

Enhanced Autopilot does.

It's only a matter of time.

-Crissa

 

[firsttruck]

Battery availability & cost may not be a big issue. The future shortage and expense will be because of the nickel used in high performance batteries.

For trailers, use LiFePO4 (LFP) which will be much cheaper and more widely available.

With semi trucking there is a combined weight limit on most U.S. state roads of 80K lbs.
This can be a problem for battery based trucks because the trucks weight more than gas/diesel trucks. But many trailers loads are not on the heavy side. For example if you have a trailer full of potato chips, many snack foods, pillows, stuff made of foam, and many other items that take a lot of space but weigh little, the trailer could have a lot of battery weight underneath and not exceed the limits.
Why should all Tesla Semis carry all those batteries around when many trailer loads do not need it or the trailer could provide the power themselves.

 

[TI4Dan]

W

I don't think Tesla should get in the trailer business. But what they could is build a fully compatible trailer upgrade kit that any manufacturer or most existing trailers could be retrofitted with.

This would consist of:
1.) a single hub motor in roughly the 20 hp range
2.) A scalable battery pack Say 20 Kwhr increments.
3.) A super capacitor module.
4.) A software/bluetooth interface with the truck.

A small hub motor is all that is really needed to account for the addition of drag and rolling resistance on a trailer. It might be able help get rolling but would be tuned for 45 MPH and greater speed. 20 hp should capture 90% of regeneration (due to the trailer) except for emergency or very hard deceleration. The supercapacitor would help get that mass going again in stop and go without taxing the main battery and maybe protect the batteries from hard stop overvoltage charging. The batteries could be moved from trailer to trailer or where ever you have power needs. That would be the major cost of this system. An onboard 240 volt charger should suffice for everyone who doesn't tow 80% of the time. Forget the DC supercharging on the trailer. The software could have 1000s of trailers preprogrammed to interface with the CT trip computer. On a sustained down grade you might be able to optimize regen to allow the trailer to take it all. The software could anticipate the topography and decide when to apply or conserve power from the trailer, maybe even charge on the flats.

Yeah you might wear out one tire quicker but this would fix most of the problems with pulling trailers for a relatively small cost.

Pulling a trailer and losing travel distance is a problem all vehicles face no matter the fuel used. Consumer trucks can put in skip tanks in the truck that adds fuel capacity from 30 Gallons to 100 Gallons. I like adding range to CT but the cost and added weight to the trailer plus complexity of a added drive system to a trailer. If I wanted more range out of CT I would get the tri motor. Spend less money, trailer is much lighter and less maintenance, less things to go wrong. I want to add another thought here the RV industry has a really bad record for customer satisfaction. If you expect excellence from Tesla, the rv industry will leave you very unhappy, I have owned enough of them, plus do a search for RV problems and it's very sad what happens to good people. I had a class C motorhome with a 26 gallon tank my safe range was 200 miles and drive right to the fuel station. I wanted more range and unless I wanted to reengineer the fuel system it just was not worth it. The CT is where I would put all my money, you get more range and it's easier to take care of and let's say it's not enough it, you can sell CT. I would think Tesla will always improve CT. I am not say putting battery pack, drive axle, motor inverter and controller with a on board charger would not work but for the money ,investing in more CT.....but I did not read which Cybertruck you were thinking of?
I wish I could buy a Cybertruck with a 300 mile range pulling 9Klbs trailer, probably not next year. I wonder if Elon has thought of all the ways we want to use Cybertruck.

 

[ajdelange]

I think Elon already said Cybertruck would in realtime sense some towing load characteristics. The Cybertruck will already know if it is traveling on level surface or up/down hill. Based on increased torque needed to accelerate, regen when braking Cybertruck & trailer, increased power usage needed for steady cruise with trailer vs none, up/down hill power needs the Cybertruck would have a lot of info

Could Cybertruck detect wind direction & speed?

I'm pretty sure the Teslas have inertial sensors at least linear ones and possibly rotational too but I cannot state that as a fact. With these it would be able to estimate the mass of the vehicle based on torque and acceleration measurements. A simple strain gauge (or gauges) in the hitch would allow the onboard computer to make estimates of trailer mass as well. I believe the basic towing mode features will be improved range estimates with trailers based not just on past consumption and sway reduction through rear wheel torque vectoring. But we'll have to wait and see about this. All just conjecture on my part at this point.

Could it detect wind direction and speed? Yes, probably. Would it? Don't know.

 

[ajdelange]

This makes me wonder if FSD will be able to work with a trailer

In the current versions trailer mode disables some autopilot functions.

Among other problems a trailer would block the view of the rear facing sensors so the system would not know what's behind it.

 

[ajdelange]

But many trailers loads are not on the heavy side.

There's a whole segment of the trucking industry referred to as "partial load" or something like that. This is for applications such as moving product between warehouses or to distribution centers. It is assumed that the Semi will preferrentially serve this segment rather than the long distance hauling part. But there is a simple solution to serving the long haul market too. That's what I call the Pony Express model. The Semi runs however far it can with a full load and arrives at a service center either operated by the truck line or someone else. There he unhitches the tractor and hitches a fully charged one to the load and is on his way in a few minutes.

 

[firsttruck]

many trailers loads are not on the heavy side. For example if you have a trailer full of potato chips, many snack foods, pillows, stuff made of foam, and many other items that take a lot of space but weigh little, the trailer could have a lot of battery weight underneath and not exceed the limits.
Why should all Tesla Semis carry all those batteries around when many trailer loads do not need it or the trailer could provide the power themselves.

OK, I think I found the industry term to what I described.

"cubing-out"/"volume constrained"/"deck area-constrained" is volume or deck/floor area of trailer is full but the maximum weight for trailer was not reached.
weight of lightweight matter or objects.
Like potato chips, many snack foods, pillows, stuff made of foam, and most goods take a lot of space but weigh little so combined weight of the semi & trailer is under 80K lbs. 80-90% of trailers are like this which is good news for Tesla Semi & other electric semis because their extra weight vs ICE semis will not be a big impediment to using EVs. So in most case then only need to worry about range.

"weighing-out"/"weight constrained" is maximum weight for trailer load reached but there is still a lot of volume/space unfilled in trailer.

Transportation Energy Data Book: Edition 38.1
2018 Feb
https://tedb.ornl.gov/wp-content/uploads/2020/02/TEDB_Ed_38.pdf
energy.gov - Distribution of Trucks by On-Road Vehicle Weight
May 31, 2010
https://www.energy.gov/eere/vehicles/fact-625-may-31-2010-distribution-trucks-road-vehicle-weight

According to weigh-in-motion data collected by fifteen states, the majority of 5-axle tractor-trailers on the road weigh between 33,000 and 73,000 lbs. Eleven percent of the tractor-trailers had weight recorded around 72,800 lbs and 10% around 68,300 lbs. Another 10% of tractor-trailers were on the lighter end of the scale – around 37,500 lbs. These data show that only a small percent of trucks on the road are near the maximum roadway gross vehicle weight of 80,000 lbs. Thus, most trucks are filling the trailer space to capacity (cubing-out) before they reach the maximum weight limit (weighing-out).

 

[TheLastStarfighter]

I think adding a motor to the trailer would add unnecessary complexity. The truck already has more than enough power. Towing range is an issue for EV's for sure. I think the easy answer - and the answer Tesla is going with - is to just have lots of charging options. This will be necessary for the Semi as well.

If you were to integrate something into the trailer, I would suggest just extra battery storage that can charge the truck when the towing trip brings you somewhere that charging options aren't abundant.

 

[ajdelange]

A generator in the bed is hardly elegant and hardly quick but it is certainly more practical than what is being suggested here. A trailer with a Megapack and L3 charger (and enough room for some payload) which one could rent might find some market.

 

[Crissa]

The motor in a trailer wouldn't be about 'adding power' it would be about adding efficiency and safety.

It wouldn't need a very complex drive controller, like the truck does. It would just be there to spin up electrons instead of shedding energy as heat.

-Crissa

 

[firsttruck]

The motor in a trailer wouldn't be about 'adding power' it would be about adding efficiency and safety.

It wouldn't need a very complex drive controller, like the truck does. It would just be there to spin up electrons instead of shedding energy as heat.

-Crissa

Also a motor in trailer gives chance to recover energy from braking & reduce brake wear.
With big trailer the Semi can not do all the braking especially quick stops or steep grades. A lot of trucks going over mountains.

Brake repair involves services including brake pad replacement, resurfacing rotors, and if damage is severe, full replacement of brake system components. In general, brake pads need replacing every 50,000 miles. The rate of wear can vary, however, based on several factors including how often you drive, the weight of your cargo, and road conditions. Exposure to dirt, grime, and road salt can also cause corrosion on rotors and other truck brake components.
https://bettstruckparts.com/truck-repair/brake-services/


http://mobilesemitruckrIn general, brake pads need to be replaced every 50,000 miles. However, the degree of wear can vary depending on several factors, including the frequency of driving, the weight of your cargo and road conditions. Exposure to dirt, dirt, and road salt can also corrode rotors and other truck brake components.epairs.com/brake-adjustment

 

[OneLapper]

Adding a motor to a trailer is simply unsafe. Here's why:

A trailer can become unstable if there is too little tongue weight on the trucks hitch. You can mitigate this dangerous situation by applying the trailers brakes if the driver is clear headed enough to do this, and do quickly enough. Applying only the trailer brakes will transfer weight from the trailer to the trucks hitch, temporarily applying the needed tongue weight to stabilize the truck and trailer.

If you add a motor to the trailer, with the thought of "pushing" or even providing a neutral drag affect, it will un-weight the hitch and create the dangerous scenario described above.

 

[Crissa]

Adding a motor to a trailer is simply unsafe. Here's why:

A trailer can become unstable if there is too little tongue weight on the trucks hitch. ...

I don't think you understand how electrical motors work.

-Crissa

 

[OneLapper]

I don't think you understand how electrical motors work.

-Crissa

Well, we can use a big windup spring traction motor instead for this example.

I'm not sold on adding power to the trailer wheels. I don't see the advantage. Maybe adding a battery pack to the trailer would be helpful to extend range, but power and or regen are not short supply with the CT