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Tesla Semi

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Re: Tesla Semi

#531

Post by arghwhat »

greglindahl wrote: post #485
PinguTS wrote: post #317

Earlier quoted context omitted.

Sorry, for not checking Wikipedia. Because I work in the industry as an electrical engineer defining standards, and owning a historic truck myself just for fun, because I can. Originally, it is right that retarders were introduced to just having a non-destructive brake by just wasting the energy. That was around the 1980s. This was just to save maintenance cost as brakes were a big part of that costs. The trucking in…

Regenerative brakes in an electric car use the engine, and add no weight and no complexity.

*motor. Engines are a type of motor that convert heat into mechanical energy (like, say, an internal combustion engine).

(Just being pedantic)

Re: Tesla Semi

#532

Post by Sohcahtoa82 »

mncolinlee wrote: post #406

It's bizarre that the Semi has way less attention than the Roadster on HN. The Roadster is a $250k car for people with money to burn. It doesn't seem to drastically change the equation from a Rimac Concept One with six-year newer battery and motor tech and savings from volume and automation. The Roadster is the shiny thing that sells less sexy vehicles. The Semi has the potential to change an entire industry if execu…

> $250k

Correction: It is a $200k car. The $250k is for a "Founder's Series" which is really just one of the first 1,000 cars out of the factory.

Still a car for people with money to burn, though. I was hoping to be able to get one, but the price is slightly over my budget. I might be settling with a Nissan GT-R.

Re: Tesla Semi

#533

Post by kingnothing »

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.

And what's the cost of those busses plus charging infrastructure and the risk of new technology versus overhead power lines like what's deployed throughout much of San Francisco, for example?

Re: Tesla Semi

#534

Post by gok »

PhasmaFelis wrote: post #135
King-Aaron wrote: post #94

Earlier quoted context omitted.

> Because the days of a service manual and a backyard shed are over They really aren't, as much as the manufacturers like to tell you they are. Sure, the sheer amount of sensors/vacuum systems/electronics/etc make it look too complex for the layman, but as long as you've got an OBD scanner and a laptop, you can make quick work of most things. The biggest issue is manufacturers currently having an obsession with inver…

Security screws on purchasable goods really need to be banned for anything that doesn't pose an immediate and extreme health and safety hazard.

Particularly in the era of self driving cars, wouldn't vehicle parts qualify for that?

Re: Tesla Semi

#535

Post by bduerst »

eric_the_read wrote: post #504
bduerst wrote: post #483

Earlier quoted context omitted.

Wasn't the space shuttle and it's SRBs reusable?

In the sense that both were effectively rebuilt from almost-but-not-quite-scratch for each launch, yes.

Despite claims about the future, doesn't SpaceX also refurbish their SRBs between flights?

Re: Tesla Semi

#536

Post by SigmundA »

013a wrote: post #493
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.

The Roadster is probably all battery, no reason to think its not 2000 lbs of battery and 1000-1500 lbs of car.

Is there anything to indicate lithium batteries will somehow get 60-70% lighter in 2 years?

Re: Tesla Semi

#537

Post by woodandsteel »

sebleon wrote: post #449
SigmundA wrote: post #443

Earlier quoted context omitted.

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.

How effective is regenerative breaking?

For buses it is very effective, since they stop every few blocks, whether the stop signal is red or not. It also makes for a huge saving on brake repair and replacement, which you can imagine is a big expense for buses.

Also city buses usually drive under 200 miles a day and then sit overnight so you can have relatively small batteries. All in all, it is hard to think of a type of vehicle where battery power makes more economic sense, and gives you more advantages over ICE.

Re: Tesla Semi

#538

Post by woodandsteel »

arghwhat wrote: post #531
greglindahl wrote: post #485

Earlier quoted context omitted.

Regenerative brakes in an electric car use the engine, and add no weight and no complexity.

*motor. Engines are a type of motor that convert heat into mechanical energy (like, say, an internal combustion engine). (Just being pedantic)

Thank you. I always wondered what was the difference.

Re: Tesla Semi

#539

Post by JabavuAdams »

tialaramex wrote: post #530
JabavuAdams wrote: post #391

Earlier quoted context omitted.

For quantifying discrete objects, you should use "fewer", not "less". "Less" is used for aggregates, continuous media, and numeric values. So, "fewer people", but "less water".

You needn't do this. Some random bloke thought it'd be a good idea years ago, wrote it down in a book. A certain type of pedant says to themselves, oh somebody wrote it down in a book - that's the rule them. Nope. You can't use fewer in some places, but the insistence that if you can use it then you must is an zombie rule. If "less" sounds right it's fine.

Thanks for that, but it doesn't sound right.

Re: Tesla Semi

#540

Post by smoyer »

This would have been a great product to announce on April Fools day - then continuing to announce it as real afterwards.
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