Tesla Semi • Hacker News Board

Re: Tesla Semi

#491

Post by bonestamp2 » Fri, Nov 17, 2017, 6:18 PM UTC

SigmundA wrote: post #403

gok wrote: post #401

Earlier quoted context omitted.

> A Diesel engine, transmission and fuel for 500 miles is about 5,000 lbs. You often end up carrying more fuel than you need so you can buy it in cheaper places. And then there’s the whole art of timing your fuel stops around the weigh stations... > still $100k cost just for the battery. The battery cost is as much as a new Semi's price. That’s not that crazy if they can actually deliver on the operating cost savings…

At 7 lbs a gallon for diesel most semis can carry 200 gallons so add an extra 1000lbs if you like, the Tesla still has to make up 5000 lbs while having 1/3rd the range. Timing stops for megachargers will be a whole lot more difficult than truck stops until they are as ubiquitous. If you have to use a plain old supercharger your talking 8-10 hours for a charge, don't even bother with a normal plug of any kind.

At least the weight will be (measurably) consistent no matter how much charge is in the battery. That said, they still weigh more than diesel so I assume they'll pay more at the scales.

Re: Tesla Semi

#492

Post by s0rce » Fri, Nov 17, 2017, 6:18 PM UTC

SigmundA wrote: post #373

Anyone else find it odd they don't talk about the battery? 500 miles of range at 2kwh a mile is a 1000kwh battery which is 10 model S batteries. Model S battery weighs 1,200 lbs lets assume they somehow improved on that by 20-30% so this is a 10,000 lb battery. Not sure how much the motors weigh, the Tesla motor and inverter are about 350lbs so lets say another 1000lbs. A Diesel engine, transmission and fuel for 500…

How do you deliver 1.6 MW, is the plan the same voltage as the supercharger (480V) or some HV system?

Re: Tesla Semi

#493

Post by 013a » Fri, Nov 17, 2017, 6:22 PM UTC

SigmundA wrote: post #373

Anyone else find it odd they don't talk about the battery? 500 miles of range at 2kwh a mile is a 1000kwh battery which is 10 model S batteries. Model S battery weighs 1,200 lbs lets assume they somehow improved on that by 20-30% so this is a 10,000 lb battery. Not sure how much the motors weigh, the Tesla motor and inverter are about 350lbs so lets say another 1000lbs. A Diesel engine, transmission and fuel for 500…

Your estimations are probably very far off.

The Roadster was announced with a 200kwh battery, which is twice the capacity of the best Model S. Yet the Roadster is much smaller, and the 0-60/quarter mile times indicate that it is much lighter.

So, we can conclude that Tesla is accounting for some real technology optimization in their batteries over the next 4 years, which I'm sure the Semi will see as well.

Re: Tesla Semi

#494

Post by bonestamp2 » Fri, Nov 17, 2017, 6:23 PM UTC

I hope Tesla builds the next gen USPS delivery trucks to replace all of those loud little trucks that sound like a space shuttle launch between each mailbox.

Re: Tesla Semi

#495

Post by splouk » Fri, Nov 17, 2017, 6:26 PM UTC

Does anyone with some technical knowledge of batteries and solar panels know whether it would be possible to put solar panels on top of the trailer and charge the battery that way?

Re: Tesla Semi

#496

Post by specialist » Fri, Nov 17, 2017, 6:27 PM UTC

SigmundA wrote: post #443

ZeroGravitas wrote: post #432

Earlier quoted context omitted.

If you take the Model S and scale it up then people have said the battery is half the cost of the car, and therefore the battery alone is roughly the cost of a normal car. I don't think it would be suprising if the same is true for the semi. There's at least one rural delivery man who bought a Tesla Model S and paid for it by using the mileage payments he gets for his job. So as long as your route fits, the same kind…

Urban buses are very different and a more obvious target. Stop and go slower avg speed regular short routes with a home base to charge. Much smaller batteries and taking advantage of regenerative braking. It is an obvious use case for batteries right now.

A relative is super gung ho for electric buses. The evangelist / champion at an energy company. His vacations are scheduled around various unveiling events, so he can get pics. Kinda reminds me of train enthusiasts.

Any way. Per what cousin tells me, I think short haul urban centric anything is ripe for electric vehicles. Delivery trucks, buses big and small, service vehicles. Maybe even tow trucks (wreckers).

Re: Tesla Semi

#497

Post by EADGBE » Fri, Nov 17, 2017, 6:35 PM UTC

PinguTS wrote: post #261

njarboe wrote: post #199

Earlier quoted context omitted.

He states that they have spent a lot of time talking to truckers and truck companies. I would guess they believe that with an electric drive train repairs and maintenance will be an order of magnitude lower (not sure how that works for tires and wheels). Body damage should also be much lower with automatic breaking and other features of enhanced autopilot. As Musk said, broken glass is a big cost for trucking as you…

Over the last centuries there were a number of truck and bus manufacturers who tried the single/middle seat design. It was never a seller for any of those. If you take someone with you, you don't want to sit him/her to sit behind you. You want them to sit next to you. If you are on the road in the city, you have often colleagues with you, like in a moving company and alike. Such trucks are used in construction work w…

Don't forget the OTR truckers who frequently like to bring a large companion pet with them, too.

Re: Tesla Semi

#498

Post by rainbowmverse » Fri, Nov 17, 2017, 6:39 PM UTC

splouk wrote: post #495

Does anyone with some technical knowledge of batteries and solar panels know whether it would be possible to put solar panels on top of the trailer and charge the battery that way?

Here's a discussion I found on the subject: https://www.reddit.com/r/solar/comments/4h7gd1/solar_panels_...

Re: Tesla Semi

#499

Post by CamperBob2 » Fri, Nov 17, 2017, 6:39 PM UTC

masklinn wrote: post #258

tbabb wrote: post #214

Earlier quoted context omitted.

"Well, it's a fraction of the cost to operate, but if a tire blows, the mechanic will have to detach a piece of plastic. So I think we'll pass."

It's way beyond that. 1. it makes changing a tire more complicated, and time is money, the longer it takes to change a blown tire the higher the penalties 2. when a semi tire goes, it goes hard , as GP noted with this arrangement the cowling will probably shatter, requiring a replacement (not just a replacement tire) and the pieces taking out other tire. If the cowling does not break, it will funnel bits of tire stra…

when a semi tire goes...

... it's usually because the company was too cheap to buy anything but retreads.

Re: Tesla Semi

#500

Post by EADGBE » Fri, Nov 17, 2017, 6:45 PM UTC

emptyfile wrote: post #456

ajmurmann wrote: post #402

Earlier quoted context omitted.

I believe the main reason for why European trucks look soi different is regulations. European trucks have a length limit that covers the tractor as well as the trailer. Because you want to maximize the cargo space, the tractor is made as short as possible and gets this very un-aerodynamic shape. The truck in essence gets the shape that best fills in all permitted space. In addition they don't have plows or similar th…

Huh, how do American trucks look?

Just to clarify, cab-over trucks are still being used today in the US, though most new ones are smaller cargo-sized. From time to time, I've seen existing COE trucks used; but mostly for private farm use (as they're not nearly as popular as they once were here, and are getting long in the tooth).

https://www.reddit.com/r/cars/comments/16vmzp/why_are_americ...