Semi takes its first business trip

[SMAlset]

Thank you. Then why would they have different shapes in the front? One of them has a curved aerodynamic skirt and the other doesn't

Were you talking about the hood on the two cabs? From the Reveal event there were two different hoods for matching to different size trailers. The silver one had the large hood (as seen in the cargo run) and the dark gray one had a shorter profile hood with a shorter trailer to match.

For these cargo runs either when they rented the trailers from the leasing company they didn't have shorter trailers to match to that cab profile (and/or maybe had a large load of batteries so needed the larger trailer) or maybe they were testing the shorter cab with a taller trailer to get numbers on mileage for that type of use.

 

[Blup85]

Not super exciting, guess you had to be there.
I should also mention they said they were going to charge for an hour, and they started charging around 1:15 In Rocklin heading to Fremont

 

[SMAlset]

@Blup85 the silver trailer looks massive, not exactly the easiest thing I'm sure to drive into a parking lot like that. Noticed in your video that some of the Supercharger area he pulled next to was cordoned off with orange cones. Wonder if that was done in advance for him. I did find a few other videos posted by people I guess you were there charging with. Love how quiet the semis are and nice not to hear the downshifting and idling of the engine. Best thing I'm sure is no diesel fumes. I'm really fascinated by these semis.

 

[dpeilow]

Given that some of the EV blog sites are speculating that as this supercharger is only 130 miles from the Gigafactory, the truck doesn't have the range, maybe locals can confirm:

- If this was day 2, were they there on day 1 as well? Probably not if all the staff rushed out to see them.
- Were they seen in the Fremont area before that?
- Did they leave the supercharger and head west or east?

Presumably they would recharge at Fremont before the return trip anyway, so it wasn't like they did 75% of a round trip.

 

[mongo]

Given that some of the EV blog sites are speculating that as this supercharger is only 130 miles from the Gigafactory, the truck doesn't have the range, maybe locals can confirm:

- If this was day 2, were they there on day 1 as well? Probably not if all the staff rushed out to see them.
- Were they seen in the Fremont area before that?
- Did they leave the supercharger and head west or east?

Presumably they would recharge at Fremont before the return trip anyway, so it wasn't like they did 75% of a round trip.

Semis were stated by Tesla personnel as 300 mile versions.
Donner Pass is 7,200+ feet in elevation and requires 220kWh of energy for a full 80k load. That is likely around 140 miles of range just for vertical displacement. The pass is about 200 miles into a trip from Fremont, so exceeds the spaced number.

They have different trailer numbers so this is likely a return to GF1 trip. 4-6 hours each way, running them in daylight for now when traffic is better and it is easier/ safer to deal with any issues.

GF1 to Fremont would likely not require a recharge en route. ~240 driving miles, 4,000 ft (80ish miles) of net elevation drop.

 

[dpeilow]

Donner Pass is 7,200+ feet in elevation and requires 220kWh of energy for a full 80k load.

Any idea what they might be bringing back to the gigafactory?

 

[mongo]

Any idea what they might be bringing back to the gigafactory?

Possibly (in decreasing order of likelihood)
Empty dunnage for motors/ packs.
Dead weight for testing.
Non-GF 2170 Cells
Solar panels that are routed through CA (wild wrong guess)

 

[Ulmo]

I’m pretty sure the silver trailer is similar to the one that was used in the Semi Reveal if not the same. The metal trim at the top and bottom sides of the trailer look to be the same with the exception that this road version one now has red reflectors all along the bottom edge. Probably a very smart safety addition for traffic approaching perpendicular to the truck.

That’s required by many regulations. Since I’m not a constitutional expert, I couldn’t tell you whether those regulations hold legal water, but you sure get tickets, higher insurance, and get fired from driving jobs, for not following them. Besides, they’re just good ideas that work; that part of the regs is just sensible.

 

[Ulmo]

Elon posted his tweet on the 7th that they were leaving the Gigafactory and Blup85's photos and these subsequent videos were seen on the 8th so suspect it was a second run. I agree about the unloading time and leaving trailors behind for that. That would make a lot of batteries going to the Factory.

Just read your post @Blup85. Thanks for the additional clarification!

I think they might even be driving at night. If that’s the case, they’ll get a lot out of them.

 

[scaesare]

They used the coolest extension cord ever . Looks like it can be paired with two Superchargers. Looked like a homemade open evse box

So I've been thinking about this.

The video of the inside of the semi charge port that we saw showed four pairs of pins, and with just the glance they looked similar to a pair of pins in a standard Model S charge port, in terms of diameter anyway (length was hard to guage).

So it's interesting that this supercharger adapter box connects to a pair of superchargers. I wonder if the truck-side connection is using only 2 of the 4 pairs of pins for this test application?

And if so, I wonder how this is being done:

- Are the superchargers paralleled in the adapter box and that combined current is delivered to the whole pack? If so I'd expect that each supercharger would have a separate command channel established by the adapter box. (And no stall sharing with other cars).

- Is the pack built so that contactors can break it up in to individual sub-units for charging independently? If so this would require some careful balancing of the charge session.


If we use @mongo 's 1.6KWh/mi value, then these 300 mile trucks would be ~480KWh packs. (before buffer). That means each could use the full output of a pair of 135KW superchargers (120KW max ea.?) for quite a while.

 

[mongo]

So I've been thinking about this.

The video of the inside of the semi charge port that we saw showed four pairs of pins, and with just the glance they looked similar to a pair of pins in a standard Model S charge port, in terms of diameter anyway (length was hard to guage).

So it's interesting that this supercharger adapter box connects to a pair of superchargers. I wonder if the truck-side connection is using only 2 of the 4 pairs of pins for this test application?

And if so, I wonder how this is being done:

- Are the superchargers paralleled in the adapter box and that combined current is delivered to the whole pack? If so I'd expect that each supercharger would have a separate command channel established by the adapter box. (And no stall sharing with other cars).

- Is the pack built so that contactors can break it up in to individual sub-units for charging independently? If so this would require some careful balancing of the charge session.


If we use @mongo 's 1.6KWh/mi value, then these 300 mile trucks would be ~480KWh packs. (before buffer). That means each could use the full output of a pair of 135KW superchargers (120KW max ea.?) for quite a while.

If the semi has one unified pack, then the Superchargers could theoretically parallel their outputs and run in current controlled voltage limit mode.
If the semi uses four electrically independent pack units, then the cord could combine the 2 superchargers and then use contactors to select which of the 4 sub unit to charge. Alternatively, each input could have two possible outputs so that there is no Supercharger paralleling to deal with and each module charges at normal SC rate (my personal favorite option). One input could have the option of all four outputs for simplicity in the single Supercharger case.

With an intelligent (CAN style) bus on the pilot pin, the semi can report 4 different charge current limits to the smart cord for control of the Superchargers.

 

[George S. Bower]

Semis were stated by Tesla personnel as 300 mile versions.
Donner Pass is 7,200+ feet in elevation and requires 220kWh of energy for a full 80k load. That is likely around 140 miles of range just for vertical displacement. The pass is about 200 miles into a trip from Fremont, so exceeds the spaced number.

.

My engineering partner and I have a route model of the semi and we modeled a run to GF and back. Our model shows that it would take 474 kwh to get to the top of donner pass. We also estimated that the 300 mile range truck would have a 510 kwh battery.

So the 300 mile truck is so marginal that must be why they are supercharging at Rocklin.

Did anyone see what the end of the supercharger cable looked like??

I'm thinking Tesla modified a supercharger to megacharger standards.

 

[mongo]

My engineering partner and I have a route model of the semi and we modeled a run to GF and back. Our model shows that it would take 474 kwh to get to the top of donner pass. We also estimated that the 300 mile range truck would have a 510 kwh battery.

So the 300 mile truck is so marginal that must be why they are supercharging at Rocklin.

Did anyone see what the end of the supercharger cable looked like??

I'm thinking Tesla modified a supercharger to megacharger standards.

Would you mind sharing your assumptions?
I'm showing 200 miles to the pass from Fremont, 220 kWh vertical burden (7,200 ft 80k lbs), with your 1.7 kWh/mile battery size, that would be 340+220 = 560 kWh to the top of the pass. Backing out from 474 kWh, the 200 mile trip to the summit uses 274/200 = 1.37 kW/mile.

 

[Cosmacelf]

It is likely or at least possible that neither the pack nor the charging setup is similar to what will be in the production trucks. So I wouldn’t draw too many conclusions from their charging stops and technology.

 

[scaesare]

If the semi has one unified pack, then the Superchargers could theoretically parallel their outputs and run in current controlled voltage limit mode.
If the semi uses four electrically independent pack units, then the cord could combine the 2 superchargers and then use contactors to select which of the 4 sub unit to charge. Alternatively, each input could have two possible outputs so that there is no Supercharger paralleling to deal with and each module charges at normal SC rate (my personal favorite option). One input could have the option of all four outputs for simplicity in the single Supercharger case.

With an intelligent (CAN style) bus on the pilot pin, the semi can report 4 different charge current limits to the smart cord for control of the Superchargers.

Yup... several possibilities here. Given that the motors/inverters are Model 3 units, I'm assuming that the pack as a whole is a 400V pack, and that it's not an 800V pack divided for charging purposes.

It will be interesting to see if a 4 Supercharger-in-to-8 pin-truck-out adapter ever shows up... perhaps for the 500 mile range model?

 

[mongo]

It will be interesting to see if a 4 Supercharger-in-to-8 pin-truck-out adapter ever shows up... perhaps for the 500 mile range model?

I think that is a Megacharger (4 channels worth of SC or 4 PowerPacks connected at the DC-DC outputs). Otherwise you need 4 empty non paired stalls available while blocking everyone else..

 

[George S. Bower]

Would you mind sharing your assumptions?
I'm showing 200 miles to the pass from Fremont, 220 kWh vertical burden (7,200 ft 80k lbs), with your 1.7 kWh/mile battery size, that would be 340+220 = 560 kWh to the top of the pass. Backing out from 474 kWh, the 200 mile trip to the summit uses 274/200 = 1.37 kW/mile.

I redid the numbers as I had some mile posts's wrong. Donner is a bit further than I had in the first run.

New numbers show a total kwh's used to get to donner pass without charging=586 kwh's a bit more than the 300 mile truck can handle.

Model assumptions in figure 4 here:
Tesla Semi Must-Have: Trailer with Regeneration, Full Aero Treatment

 

[scaesare]

I think that is a Megacharger (4 channels worth of SC or 4 PowerPacks connected at the DC-DC outputs). Otherwise you need 4 empty non paired stalls available while blocking everyone else..

For production, yeah... but I wonder if they'll hack something up when they get some 500 mile test rigs on the road.

 

[gg_got_a_tesla]

They seemed.... loud?

 

[scaesare]

They seemed.... loud?

Air brakes (and maybe a compressor noise, as well... not sure).

But if you mean the acceleration noise in this one, it sounds like the gear reduction units to me.. you are right, not the quietest. Perhaps straight-cut gears as those are often used in high-rating applications: