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RegGuheert
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Re: Tesla Semi Truck

Fri Mar 09, 2018 11:25 am

RegGuheert wrote:Here is some more discussion on the LOADED energy estimated to get the Tesla Semi from Fremont to the top of Donner Pass:
InsideEVs wrote:Our modeling shows that the kWh burn to get to the top of Donner Pass is 587 kWh’s.
Also
InsideEVs wrote:According to an ongoing thread at Tesla Motors Club, the drivers have said that the trucks are both 300-mile range versions.
But I'm wondering if they contain 400-V batteries or 800-V batteries. My guess is 400-V batteries OR they have a DC-DC converter included just for charging from Superchargers.

Off to read the thread mentioned discussing this subject.
RegGuheert
2011 Leaf SL Demo vehicle
10K mi. on 041413; 20K mi. (55.7Ah) on 080714; 30K mi. (52.0Ah) on 123015; 40K mi. (49.8Ah) on 020817; 50K mi. (47.2Ah) on 120717; 60K mi. (43.66Ah) on 091918.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

lorenfb
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Re: Tesla Semi Truck

Fri Mar 09, 2018 11:28 am



Again, where is a base range analysis of a EV semi full loaded traveling at 60 mph on level terrain, i.e. assuming the same load
capacity as a diesel semi? It's not difficult!
Leaf SL MY 9/13: 66K miles, 50 Ahrs, 5.2 miles/kWh (average), Hx=70, SOH=78, L2 charges to 100% > 1000, max battery temp < 95F (35C), min discharge point > 20 Ahrs

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RegGuheert
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Re: Tesla Semi Truck

Fri Mar 09, 2018 11:32 am

lorenfb wrote:
Again, where is a base range analysis of a EV semi full loaded traveling at 60 mph on level terrain, i.e. assuming the same load
capacity as a diesel semi? It's not difficult!
Who said anything about level ground? I estimated that and unloaded trip from the Gigafactory to Fremont would consume about 300 kWh based on a simulation result that said the trip would take about 378 kWh when fully loaded.
RegGuheert
2011 Leaf SL Demo vehicle
10K mi. on 041413; 20K mi. (55.7Ah) on 080714; 30K mi. (52.0Ah) on 123015; 40K mi. (49.8Ah) on 020817; 50K mi. (47.2Ah) on 120717; 60K mi. (43.66Ah) on 091918.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

lorenfb
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Re: Tesla Semi Truck

Fri Mar 09, 2018 11:58 am

RegGuheert wrote:
lorenfb wrote:
Again, where is a base range analysis of a EV semi full loaded traveling at 60 mph on level terrain, i.e. assuming the same load
capacity as a diesel semi? It's not difficult!
Who said anything about level ground? I estimated that and unloaded trip from the Gigafactory to Fremont would consume about 300 kWh based on a simulation result that said the trip would take about 378 kWh when fully loaded.


So you weren't specific on what you meant. O.K., I miss interrupted you. Again, can you answer my question? I couldn't care less about
Elon's battery transport stunt!
Leaf SL MY 9/13: 66K miles, 50 Ahrs, 5.2 miles/kWh (average), Hx=70, SOH=78, L2 charges to 100% > 1000, max battery temp < 95F (35C), min discharge point > 20 Ahrs

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RegGuheert
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Re: Tesla Semi Truck

Fri Mar 09, 2018 12:07 pm

lorenfb wrote:So you weren't specific on what you meant.
Yes, I was. You could only misinterpret the post that you quoted if you didn't read the entire post and even then only if you completely ignored the fact that we are discussing hauling batteries from the Gigafactory to Fremont.
RegGuheert
2011 Leaf SL Demo vehicle
10K mi. on 041413; 20K mi. (55.7Ah) on 080714; 30K mi. (52.0Ah) on 123015; 40K mi. (49.8Ah) on 020817; 50K mi. (47.2Ah) on 120717; 60K mi. (43.66Ah) on 091918.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

GRA
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Joined: Mon Sep 19, 2011 1:49 pm
Location: East side of San Francisco Bay

Re: Tesla Semi Truck

Fri Mar 09, 2018 5:40 pm

RegGuheert wrote:
GRA wrote:I didn't see any mention of Megachargers in the article, but I just skimmed it. Was that mentioned?
I surmised that from the fact that they drove the trucks both ways. I had thought that is the only charger available for these trucks. But it seems that at least *some* of the prototypes can be charged using Superchargers, including one of the trucks used in this demonstration<snip>

Thanks.

RegGuheert wrote:
GRA wrote:Reg, like most northern CA skiers I've made the drive (both ways) many times, so I'm well aware of the elevation changes.
Yeah, that's why I called you out on characterizing this trip as "downhill".

Well, it largely is, but there is that climb at the start. It's certainly more sensible to call the westbound trip downhill than it does the eastbound one; the truck climbing lanes are eastbound!

RegGuheert wrote:
GRA wrote:The packs should fit in a container no problem (internal width about 7'8" IIRR, although whether or not the packs can be loaded lengthwise side-by-side may be a problem), the issue will be do they have to transport special racks up the hill to stack them, if so do they fold, and what do the racks weigh? I've used (non-folding) racks similar to the one on the right end of the upper gallery row here: https://tier-rack.com/application/shipping-racks.html (the picture just left of that shows the same rack folded), but there's no way they could handle the weight of a battery pack, even if putting that much weight that high up were acceptable. A battery pack could use a much lower, stronger rack. As battery packs are dense commodities maybe stacking won't be required, and using regular dunnage (plywood, foam, pallets, inflatable bags) and shipping them in a single layer will be okay.

The other option, and one that may make sense is to haul the containers to the Livermore warehouse or else a trans-shipment warehouse at the Port (in my Teamster casual days I sometimes worked at one), and consolidate 40' container loads into 48' or 53' trailers before hauling them up the hill. It will probably depend on whether or not trailers fully loaded with packs are weight critical and can't be fully loaded in any case.
Thanks, I considered that the batteries will need racking (I'm willing to bet that they do), but I hadn't thought about getting them back up the hill. Perhaps those can be transported back up with many of them in a single load.

Either can be done. It helps if they fold or are designed to stack, as it makes it possible to load them on top of other freight in rear of a container when there's room, but transshipping allows you to use them both directions. Still, there were times when there was an excess of racks on our dock and some other terminal needed them, and we'd shove a bunch of them into an empty or nearly empty trailer. Deadheading is to be avoided, but needs must. If time allowed and we were tight on space we might flip every other one upside down so we could stack them, but that shouldn't be necessary with lower battery racks.

Thinking about it, I'm pretty certain that the packs can't be loaded side by side on the floor, so racks would almost certainly be required. Does anyone have any dimensional specs on any of the Tesla packs?

RegGuheert wrote:
GRA wrote:It's a pity they weren't able to do this kind of baseline run earlier so that they could get a bad winter weather test in, because there's a good chance that they'll now have to wait until next winter for similar conditions.
You're kidding, right? I think it would be extremely foolish to make early test runs in poor weather for a large number of reasons.

Which is why I said it would have been nice if they'd made some baseline runs earlier in good weather to work out some of the early bugs, before they attempted it in bad. Hot weather testing will largely be about how components hold up to heat, while cold weather will mainly be about range. As I guesstimated and the IEVS article you quoted calculated, the 300 mile packs probably can't make the eastbound trip fully loaded even when new. I've always thought this trip would need the 500 mile packs.
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

lorenfb
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Re: Tesla Semi Truck

Fri Mar 09, 2018 8:44 pm

RegGuheert wrote:we are discussing hauling batteries from the Gigafactory to Fremont.


Like I said, who really cares about another Elon publicity stunt! But here's back to reality, which this thread seems to neglect:

Using previously calculated theoretical data and assuming a fully loaded EV semi versus a diesel semi for a trip from SpaceX (SoCal)
to Tesla Fremont (NoCal), the following best case analyses result:

I. Assumed Data
a. Route - U.S. 5 (no GrapeVine/mountains, no major grades - unrealistic )
b. Distance - 350 miles (assume 400 miles for margin)
c. Range for EV semi per previous posted calcs - .40 miles/kWh
d. Battery weight - equals original diesel drive-train (unrealistic as noted below)
e. Battery size - equals original diesel drive-train (unrealistic as noted below)
f. Speed - 60 mph
g. No charging on route needed
h. EV semi requires no additional axles (???)

II. Analysis - EV Semi

1. Required battery capacity; 400 miles / .40 miles/kWh = 1000 kWh
2. Battery weight based on using MS (1200 lbs -14 lbs/ kWh) = 14, 000 lbs
3. Present market battery cost per kWh of $100 (Panasonic discount) = $100K
4. Trip cost mile for energy ($.10 per kWh) = $100

III. Analysis - Diesel Semi

1. Required fuel @ 7.2. miles/gal ~ 60 gallons
2. Diesel fuel costs - $4.00 / gallon
3. Trip cost = $240 (cost per mile $.60)
4. Diesel engine cost (Cummins) - $10K
5. Trans & diff cost - $10K

IV. Major Key Issues for EV Semi
1. Amortization period required for battery costs
2. Significant additional overall weight/size/location requirements for battery
3. When in the future a TCO economic parity occurs relative to a diesel semi
4. Assumptions for charging infrastructure costs & build-out time
5. Optimum battery capacity versus charging time versus infrastructure versus addition driver layover (charging) costs
Leaf SL MY 9/13: 66K miles, 50 Ahrs, 5.2 miles/kWh (average), Hx=70, SOH=78, L2 charges to 100% > 1000, max battery temp < 95F (35C), min discharge point > 20 Ahrs

User avatar
RegGuheert
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Re: Tesla Semi Truck

Sat Mar 10, 2018 3:17 am

lorenfb wrote:c. Range for EV semi per previous posted calcs - .40 miles/kWh
Specification for the Tesla Semi is:
Tesla Semi webpage wrote:<2 kWh/mi
RegGuheert
2011 Leaf SL Demo vehicle
10K mi. on 041413; 20K mi. (55.7Ah) on 080714; 30K mi. (52.0Ah) on 123015; 40K mi. (49.8Ah) on 020817; 50K mi. (47.2Ah) on 120717; 60K mi. (43.66Ah) on 091918.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

lorenfb
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Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
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Location: SoCal

Re: Tesla Semi Truck

Sat Mar 10, 2018 10:41 am

RegGuheert wrote:
lorenfb wrote:c. Range for EV semi per previous posted calcs - .40 miles/kWh
Specification for the Tesla Semi is:
Tesla Semi webpage wrote:<2 kWh/mi


Overly optimistic at < 2 kWh/mi (> .50 mi/kWh)? My best case analysis indicated 2.5 kWh/mi, i.e. < .40 mi/kWh realistically.
Leaf SL MY 9/13: 66K miles, 50 Ahrs, 5.2 miles/kWh (average), Hx=70, SOH=78, L2 charges to 100% > 1000, max battery temp < 95F (35C), min discharge point > 20 Ahrs

lorenfb
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Re: Tesla Semi Truck

Mon Mar 12, 2018 2:47 pm

If Tesla is really serious about producing a EV semi in the near term, they should build two test tractors capable
of pulling a vehicle transporter loaded with seven Tesla vehicles being transferred from Fremont to the L.A. area,
by mid 2018. From what I've seen over the last 2-3 years, Tesla makes at least two deliveries per week to the L.A. area.
Initially from a battery energy perspective, a range of only about 150 miles would be necessary traveling the 101 Hwy,
thus avoiding the GrapeVine and Hwy 152 via Hwy 5. Besides, the availability of SCs is greater along the 101 Hwy,
resulting in an initial smaller battery. The data gathered would not only further corroborate the design concept and
technology, but additionally it would greatly enhance Tesla's PR with regard a EV semi.
Leaf SL MY 9/13: 66K miles, 50 Ahrs, 5.2 miles/kWh (average), Hx=70, SOH=78, L2 charges to 100% > 1000, max battery temp < 95F (35C), min discharge point > 20 Ahrs

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