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Now Tesla is begging suppliers for "cash back" and change the supplier pricing on existing contracts. Sounds like the cash incineration engine needs more green.
https://www.wsj.com/articles/tesla-asks-suppliers-for-cash-back-to-help-turn-a-profit-1532301091

This quote is veeeeeeery interesting:
Tesla will need to pay down a $230 million convertible bond this November if its stock doesn’t reach a conversion price of $560.64, and a $920 million convertible note next March if the stock doesn’t reach $359.87. Shares closed Friday at $313.58, and are down about 4.5% over the past 12 months.

Now all the fire and fury tweeting madness from Elon makes sense. He has every incentive to keep TSLA stock inflated by whatever means necessary.
 

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I can't speculate on what Porsche has been doing over the last 10 years. But part of engineering a cooling solution involves understanding how a Li-Ion battery generates heat and how it reacts to extremes of cold and hot conditions. How hot can you let the battery get before it starts to degrade unacceptably? What's "unacceptable"? That means spending a lot of time testing batteries in temperature extremes and under different charging and use scenarios.

It's easy enough to engineer a "worst case" thermal management system, but that would use more power and cost more than you'd probably want. So the designers, accountants and engineers have to come to a compromise agreement on what combination of cost, effectiveness and battery lifetime is acceptable. And they have to do the testing in order to come up with the data that's based on, and that takes time.

GM hasn't been working on the Bolt for 10 years, but they have been working with the "pouch cell" type of Li-Ion battery used in the Bolt since well before the Volt was introduced several years ago. So yeah, I think it's fair to claim that GM has been working on the thermal protection systems in the Bolt in one form or another for almost a decade.

As for Porsche? I don't know, but if they plan to start selling electric cars then I have to assume that they've been testing for some period of time. It may be that this testing has actually been underway elsewhere in the Volkswagen group of companies (of which Porsche is a member).

Skepticism is healthy, but I'd never rule anything out on a hunch.
And I was counting on you;) Who is skeptical, or operating on a hunch? Suggesting that GM's work on the pouch cell constitutes a decades worth of development on the thermal regulation system in the Bolt is stretching the hunch thingy just a little Sean.

The concepts behind heating/cooling regulation are well understood with decades of industry experience and which have in fact been applied to solutions in almost every facet of our lives. While it is true Porsche is upping the anti with faster charging rates for EV's, it would likely not require a decade of testing like the WiFi news guy was suggesting. Most mechanical systems I know of, especially ones that are attached to operator safety, require a certain amount of redundant capacity. Something tells me (less then a hunch) that determining the max temperature swings in the battery pack and mating it with an appropriately sized thermal regulation system isn't the most challenging project Porsche has undertaken in it short existence.

If you go back to the WiFi news guys article, which was the context I made my comments under, not only is he clueless about the number of reservations made for Porsche's electric car, but his claim that Porsche has spent the last 10 years working on thermal regulation to avoid the problems that Tesla and Nissan went through can be labeled nothing else but B.S. Tesla and Nissan have nothing in common here. And in the decade of Tesla's existence, it has designed and implemented numerous sizes of batteries and thermal regulation systems capable of handling a wide variation in charge/drain cycles.

But hey, you might have uncovered a major problem in Porsche's corporate structure, especially if all its designers, accountants and engineers are sitting around in a decade long meeting just to determine how fast the cooling pump should run on its upcoming electric car.
 

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Yes. I question everything (and apparently, everyone... naughty me), but I settle after I've accumulated enough trustworthy data and information. But, I'm totally willing to modify that position if new, trustworthy data arrives.

Boy, that sounds suspiciously like the scientific method...:nerd:
 

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Now Tesla is begging suppliers for "cash back" and change the supplier pricing on existing contracts. Sounds like the cash incineration engine needs more green.
https://www.wsj.com/articles/tesla-asks-suppliers-for-cash-back-to-help-turn-a-profit-1532301091

This quote is veeeeeeery interesting:
Tesla will need to pay down a $230 million convertible bond this November if its stock doesn’t reach a conversion price of $560.64, and a $920 million convertible note next March if the stock doesn’t reach $359.87. Shares closed Friday at $313.58, and are down about 4.5% over the past 12 months.

Now all the fire and fury tweeting madness from Elon makes sense. He has every incentive to keep TSLA stock inflated by whatever means necessary.
Well, not quite.
https://www.cnbc.com/video/2018/07/23/tesla-responds-report-supplier-refunds.html
 

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The concepts behind heating/cooling regulation are well understood with decades of industry experience and which have in fact been applied to solutions in almost every facet of our lives.
I think you missed my main point. The complex part isn't whether you can build a heating/cooling solution, it's "what kind of heating/cooling do the batteries need?" How much heating and cooling is needed to keep the batteries from degrading, and how much degradation is permissible over what time period? That's the crux of the matter, and it requires a lot of testing over a fair bit of time to establish. Once you know those parameters, building an optimized low-cost engineering solution to fit them is the easy part.

You simply can't sell a car with a battery warranty without having a pretty high degree of confidence that the vast majority of use cases aren't going to result in degradation that requires warranty replacement. And there are a lot of use cases, which is why the battery testing is so involved.

GM's been doing this kind testing for quite some time with the same kind of prismatic cells used in the Bolt because those cells were also used in the Volt and the Spark. So they have a very well developed testing methodology along with an actual lab to do the work in and a lot of experience with what works and what doesn't.
 

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Drat! I thought I came up with something new. :crying:

Back to the drawing board! It's this thing where I write up new ideas....
Try starting with your conclusion, then work backwards to find evidence to support it. Ignore any contrary findings, and feel free to make up supporting data as needed.

May not be too scientific, but it sure works in politics.
 

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I think you missed my main point. The complex part isn't whether you can build a heating/cooling solution, it's "what kind of heating/cooling do the batteries need?" How much heating and cooling is needed to keep the batteries from degrading, and how much degradation is permissible over what time period? That's the crux of the matter, and it requires a lot of testing over a fair bit of time to establish. Once you know those parameters, building an optimized low-cost engineering solution to fit them is the easy part.

You simply can't sell a car with a battery warranty without having a pretty high degree of confidence that the vast majority of use cases aren't going to result in degradation that requires warranty replacement. And there are a lot of use cases, which is why the battery testing is so involved.

GM's been doing this kind testing for quite some time with the same kind of prismatic cells used in the Bolt because those cells were also used in the Volt and the Spark. So they have a very well developed testing methodology along with an actual lab to do the work in and a lot of experience with what works and what doesn't.
I get your point, thanks for clearing that up. But if you take Nissan and Tesla as examples, they have compiled a lot of data on battery usage in cars, and everyone in industry can and likely does borrow from it. When Nissan makes the jump to a thermal regulation system for its Leaf, it is expected to be very similar to what Tesla and GM are currently using. 10 years of testing would not be needed in any case for the up and coming Porsche. But you are right testing is ongoing, and who knows what battery designs we will have in 10 years from now.
 

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I get your point, thanks for clearing that up. But if you take Nissan and Tesla as examples, they have compiled a lot of data on battery usage in cars, and everyone in industry can and likely does borrow from it...
I'm not an industry insider, but it seems to me that battery technology is not yet mature and companies are investing a lot of time and effort into qualifying their solutions - so it seems more likely to me that these are pretty tightly held industry secrets. Again, I'm not talking about the engineering of the basic cooling mechanics, but rather the battery chemistries, behaviours, and software implementations for things like what kinds of sensors and algorithms you need to handle charging and thermal management.
 
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