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Elon Musk's Data Doesn't Back Up His Claims of New York Times Fakery

theatlanticwire.com

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Re: Elon Musk's Data Doesn't Back Up His Claims of New York Times Fakery

#241

Post by kamaal »

stcredzero wrote: post #190
niggler wrote: post #125

Earlier quoted context omitted.

Here is my thought on the matter: The reporter's behaviors are indeed consistent with what he claims he was told by Tesla when he called them during the journey. If the car manufacturer told me that regenerative braking can help extend the mileage, as dumb as it sounds I absolutely would repeatedly brake the car. I'm not an expert in electric vehicles, and if the company is telling me this is good for the car I would…

> If the car manufacturer told me that regenerative braking can help extend the mileage, as dumb as it sounds I absolutely would repeatedly brake the car. Wow. Just Wow!

Sorry, but what are you trying to imply.

The default way in which any user thinks before acting is to trust the customer support guy. Just like how you trust your doctor, or lawyer, or your teacher.

Besides no ones studies chemical engineering before buying an electric car just to use it.

Re: Elon Musk's Data Doesn't Back Up His Claims of New York Times Fakery

#242

Post by justin_vanw »

Musk's rebuttal is too wide reaching. It makes some accusations that the evidence supports, but does not prove. This leaves his rebuttal open to a counter rebuttal, when the whole issue revolves around one facet of the data:

The reviewer left Norwich with the car telling him he could travel 32 miles, when he needed to go 62 miles. If he hadn't done that, he would not have had an issue.

The atlanticwire article doesn't address this point at all, and how could it? The car said it would go 32 miles. It went more than that, but less than 62. Any reasonable person, needing to go 62 miles, would want the number the car says to be greater than 62, because what kind of idiot tries to go 62 miles with a car with 62 miles of range left? Now, what kind of full on retard tries that with 32 miles left?

Re: Elon Musk's Data Doesn't Back Up His Claims of New York Times Fakery

#243

Post by kamaal »

MarkMc wrote: post #230
gfodor wrote: post #21

I guess it's time to muddy the waters. The truth is in the middle! Of course, the entire debacle can be summed up with the following exchange: Q: "How many miles did you have left to drive on the final leg?" Broder: "61" Q: "And how many miles did your car tell you that you could travel before recharging?" Broder: "32" Of course, Broder claims that Tesla told him it was OK to leave. I think this is bullshit, but will…

This seems to be the killer argument from Elon Musk. What's interesting is that Rebecca Greenfield doesn't see it as convincing argument at all. Here's her explanation for siding with Broder: "Broder also explains that he did not charge fully because of the time it took to charge. He wanted to show the real world experience of a real driver, who might not want to endure the hour and a half it takes to charge up, when…

No but in real world no one expects a fuel loss of 50% on a car that is just parked and left overnight.

Re: Elon Musk's Data Doesn't Back Up His Claims of New York Times Fakery

#244

Post by ju2tin »

kamaal wrote: post #236
danso wrote: post #127

Earlier quoted context omitted.

Just for reference's sake: > After making arrangements to recharge at the Norwich station, I located the proper adapter in the trunk, plugged in and walked to the only warm place nearby, Butch’s Luncheonette and Breakfast Club, an establishment (smoking allowed) where only members can buy a cup of coffee or a plate of eggs. But the owners let me wait there while the Model S drank its juice. Tesla’s experts said that…

To assume that your customer must be intelligent is the biggest mistake you can ever make. I worked at the Dell technical support call center some years back and our training said very specifically until you ascertain the caller actually knows what he is doing, you need to assume they are dumb. This saves a lot of trouble. There are countless times when some one calls and I have to explain them they can get internet…

>To assume that your customer must be intelligent is the biggest mistake you can ever make.

It's not about customers being less intelligent than you; that's an arrogant stance to take in these kinds of situations. Lots of people are intelligent enough to understand how batteries work -- or how computer programs work -- if they should choose to spend the time and effort it would take to do so.

But they're not choosing to do so. They're not your R&D team. They're your customers, and they're paying you big money for something that will make their lives easier.

In this case, they're paying for a car that's going to get them from point A to point B with no hassles, so they can focus their intelligence on problems of their choosing, not on problems with your product.

Re: Elon Musk's Data Doesn't Back Up His Claims of New York Times Fakery

#245

Post by Natsu »

kamaal wrote: post #241
stcredzero wrote: post #190

Earlier quoted context omitted.

> If the car manufacturer told me that regenerative braking can help extend the mileage, as dumb as it sounds I absolutely would repeatedly brake the car. Wow. Just Wow!

Sorry, but what are you trying to imply. The default way in which any user thinks before acting is to trust the customer support guy. Just like how you trust your doctor, or lawyer, or your teacher. Besides no ones studies chemical engineering before buying an electric car just to use it.

Nothing works with perfect efficiency thanks to entropy. The energy recaptured during braking is less than that expended while accelerating in the first place.

In other words, crazy maneuvers like that are only going to drain your battery. The lost energy will go into things like friction heating up your brake pads as you wear them down pointlessly.

Re: Elon Musk's Data Doesn't Back Up His Claims of New York Times Fakery

#247

Post by Natsu »

danso wrote: post #152
onethumb wrote: post #149

Earlier quoted context omitted.

That's not how I read it. The summary was pretty specific... "The next day" isn't a summary of the trip, it's a summary of that day. That day, the car projected 32 miles. It delivered 51. It didn't "fall short" that day.

Huh? The summary is not specific at all (that's why it's a summary). Read it again. It says: The next day, in 10-degree weather ... In fact, it's easier to look at Elon Musk's annotated version to see how it was misinterpreted: http://www.teslamotors.com/sites/default/files/blog_images/a... Notice how his red highlighted area encompasses the summary (which is in a different font-size) and the bullet-point-like annota…

I'm reading that the same way he did. When I read it, it is very clear that "that day" refers to Jan 24th. The day in which it told him it would go 32 miles and went 51.

Re: Elon Musk's Data Doesn't Back Up His Claims of New York Times Fakery

#248

Post by Someone »

Natsu wrote: post #245
kamaal wrote: post #241

Earlier quoted context omitted.

Sorry, but what are you trying to imply. The default way in which any user thinks before acting is to trust the customer support guy. Just like how you trust your doctor, or lawyer, or your teacher. Besides no ones studies chemical engineering before buying an electric car just to use it.

Nothing works with perfect efficiency thanks to entropy. The energy recaptured during braking is less than that expended while accelerating in the first place. In other words, crazy maneuvers like that are only going to drain your battery. The lost energy will go into things like friction heating up your brake pads as you wear them down pointlessly.

Regenerative braking should not use the brake pads.

More importantly: battery chemistry is weird and differs widely between technologies (for example, should you completely empty lithium ion batteries every now and then, or is that disastrous for the batteries? How is that for NiMh batteries? Does the memory effect exist? Etc.).

That overnight loss likely was (mostly) not a loss at all, but due to the difference in mileage you can get out of a warm vs a cold battery pack, or maybe even out of one that had recently seen small charge cycles due to regenerative braking vs one that hadn't (IMO unlikely, but as I said, battery chemistry is weird)

If Tesla told me that regenerative braking would improve available range in this situation, I think I would take them for their word.

Re: Elon Musk's Data Doesn't Back Up His Claims of New York Times Fakery

#249

Post by lutusp »

Someone wrote: post #248
Natsu wrote: post #245

Earlier quoted context omitted.

Nothing works with perfect efficiency thanks to entropy. The energy recaptured during braking is less than that expended while accelerating in the first place. In other words, crazy maneuvers like that are only going to drain your battery. The lost energy will go into things like friction heating up your brake pads as you wear them down pointlessly.

Regenerative braking should not use the brake pads. More importantly: battery chemistry is weird and differs widely between technologies (for example, should you completely empty lithium ion batteries every now and then, or is that disastrous for the batteries? How is that for NiMh batteries? Does the memory effect exist? Etc.). That overnight loss likely was (mostly) not a loss at all, but due to the difference in m…

> If Tesla told me that regenerative braking would improve available range in this situation, I think I would take them for their word.

Think about what you're saying.

Thesis: periodically pressing on the brake pedal and allowing some of the car's energy to be captured by flywheel generation actually improves battery life and vehicle range compared to simply driving along at the same average speed. True or false?

In order for the above to be true, and given that acceleration takes battery energy and regenerative deceleration delivers battery energy, to argue that pressing on the brakes improves battery life is to argue that braking produces more energy for the battery than acceleration requires from it -- in other words, that the car is a perpetual motion machine, free of all natural constraints and scientific laws.

But the second law of thermodynamics -- http://en.wikipedia.org/wiki/Second_law_of_thermodynamics -- says one cannot get more energy out of a system than you have put into it, in fact, you always get back less than you put in.

Beyond the above-quoted thermodynamic law, there is the energy conservation law, to wit: energy cannot be created or destroyed, only changed in form (http://en.wikipedia.org/wiki/Law_of_energy_conservation). Therefore it is impossible for the car to deliver more energy by decelerating than it acquired by accelerating.

Therefore if someone at Tesla actually offered the advice that stop-and-go driving actually increases battery life and vehicle range, that person needs remedial physics education before being allowed to speak to customers again.

Re: Elon Musk's Data Doesn't Back Up His Claims of New York Times Fakery

#250

Post by Someone »

lutusp wrote: post #249
Someone wrote: post #248

Earlier quoted context omitted.

Regenerative braking should not use the brake pads. More importantly: battery chemistry is weird and differs widely between technologies (for example, should you completely empty lithium ion batteries every now and then, or is that disastrous for the batteries? How is that for NiMh batteries? Does the memory effect exist? Etc.). That overnight loss likely was (mostly) not a loss at all, but due to the difference in m…

> If Tesla told me that regenerative braking would improve available range in this situation, I think I would take them for their word. Think about what you're saying. Thesis: periodically pressing on the brake pedal and allowing some of the car's energy to be captured by flywheel generation actually improves battery life and vehicle range compared to simply driving along at the same average speed. True or false? In…

I don't think I said that; I certainly did not intend to.

Let me retry: the amount of energy you can get out of a battery will drop slowly, but we can ignore that.

Because of the properties of the battery, the amount of energy you can get out in a form that can drive the car may be a lot lower (extreme example: 1W of power may not be enough to even drive the electronics that control the starting of the engine. If so, a 1GWh battery that is full but delivers at most 1W will not take the car anywhere)

Secondly, the amount of power that you can get out and use to drive the car will depend on the environment (temperature, in particular) and, likely, on previous charge/discharge cycles. I know I am not an expert on this, but I know this isn't simple. http://en.wikipedia.org/wiki/Lithium-ion_battery#Conditionin... shows I am not alone in that. After scrapping the 'may's, 'belief's and 'debate's, little information, if any, is left.

Also, I understand the battery control software has safeguarding against full decharging, as that would be a costly affair. That software may have quirks. Given the age of the car's design and the number of hours all cars combined have been on the road, I think it is a safe bet that it does have quirks, especially for uncommon scenarios.

If the battery had more power than the software estimated, and that that power would be able to drive the car, once the battery warmed up, it all was a matter of convincing the software about that.

If the car's manufacturer suggests multiple small recharge-charge cycles (using regenerative braking) to do that, why would I distrust them? I know almost nothing about the chemistry of the batteries, and even less about their control software.

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