Short-Term TSLA Price Movements - 2016

[jesselivenomore]

So why was TSLA worth $290 last summer, $200 in November last year, and now $240?

Um, because stuff happened?

The market believed and priced in Elon's projections for China, which were thought to rapidly approach US delivery numbers. When that failed to materialize due to fake orders, the stock went back down to sub 200. The stock ran up again in Q2 when Tesla Energy was unveiled, which opened up a whole new revenue source. And then after the Model X reveal it was clear that ramp was not yet happening(only 6 delivered), which means coming up short on year end delivery numbers, so back down to 200(also there were macro events re: china). Now we are going back up because even without meaningful Model X deliveries, it seems Model S has made up enough of the deliveries where the more bearish projections seem to be wrong. Also Model X is finally ramping.

It is not as if the stock price has just been gyrating without any reason. Stuff has been happening!

I'm not assuming this will be the case. My worst case assumption is similar to Causalien's: every car sold has to be taken in for repairs. While these repairs may not be all that costly or time consuming they would be very costly with regard to reputation.

I would say that my rough guess is that there's a +50% chance (risk) that Tesla is not coming out with an official statement or blog post to address the fire and the cause of it before Monday morning. If so, it's in my opinion, bad news pointing to an actual problem with the car and/or the Supercharger and the market will price this in.

And to get some perspective, seeing as this is the short-term thread: Whatever happens won't change the TSLA story over time one bit other than a small blip on the 5-years stock chart.

Please use some critical thinking here. There are 100k Model S's on the road. There has been hundreds of thousands, if not millions of charges used at supercharging stations over the past 4 years.

If it is as widespread a problem as you think where there is a risk of mass recalls, charging issues would have popped up long ago.

Instead this is a 1/hundreds of thousands, or 1/1,000,000 incident.

Bear in mind, this is assuming charging is 100% at fault, and it wasn't cigarette or fireworks or anything unrelated to Tesla.

In light of the above, using a little bit of critical thinking, the likelihood of mass recalls is, as I've stated before, less than 1% probability.

So with all the perspective you want, a 20% move related to this incident is HIGHLY improbable, long term, medium term, short term, micro term.

 

[Yggdrasill]

Around 200A is actually pretty much within spec of the wiring being used even by NEC standards, which is saying something since the car regularly goes well beyond specs like the NEC during normal operation based on Tesla's engineering calculations. I mean, for example, Tesla pulls 1500A through #2/0 wire in the P90D/P85D... which is almost 8x what that wire is rated for by the NEC. And heat generated is exponential here. So 200A vs 400A is 4x more heat, not 2x. Run that out to 1500A and, well, you can see why I'm pretty skeptical of 300A supercharging causing problems. One 1/4 mile run in a P90D would be ~1500A for about 9-10 seconds. Running the heat numbers out on the back of the napkin means that means that run in the P90D builds up the same amount of heat in the wiring and components as something like 3-4 minutes of 300A supercharging... in 10 seconds. Talk about stress on components! And this heat doesn't really have too far to go, so back to back 1/4 mile runs? Sheesh.

For another example, check out data I pulled from my P85D showing a ~100V sag under full acceleration at 1300A. That means 130,000 W of heat being generated. 130,000W of heat! And you're worried about 900W of heat... In my 5 second run I generated the same waste heat as a 900W loss running for over 10 minutes. I mean, these are stresses I subject my P85D to all the time, as I'm sure many others do. Really, supercharging is tame compared to heavy acceleration and such. At 1000A+ we're talking measurable physical stress on wiring and such. At 300A, not so much.

This wasn't a P85D, this was an S85. And whether or not the heat generation is problematic or not depends entirely on the distribution and duration of the heat. 130 kW can be fine, while 100W can be problematic.

Sure there is a chance that something came loose or wasn't installed correctly, or whatever. But, given that this is an older vehicle that's been on the road for several years and hadn't had an issue until yesterday... I'm going to defer to Occam's razor or other similar logic for now and just figure it's something much more obvious.

I'm certainly not saying it definitely was the HVJB. I'm just saying that if you assume this is the fault of the Tesla, the HVJB is the likely culprit. It could just as easily be the case that something caught fire in the trunk, or something similar.

Try to assume that this was the fault of the Tesla - where do you think the fire started and how?

 

[tom66]

Around 200A is actually pretty much within spec of the wiring being used even by NEC standards, which is saying something since the car regularly goes well beyond specs like the NEC during normal operation based on Tesla's engineering calculations. I mean, for example, Tesla pulls 1500A through #2/0 wire in the P90D/P85D... which is almost 8x what that wire is rated for by the NEC. And heat generated is exponential here. So 200A vs 400A is 4x more heat, not 2x. Run that out to 1500A and, well, you can see why I'm pretty skeptical of 300A supercharging causing problems. One 1/4 mile run in a P90D would be ~1500A for about 9-10 seconds. Running the heat numbers out on the back of the napkin means that means that run in the P90D builds up the same amount of heat in the wiring and components as something like 3-4 minutes of 300A supercharging... in 10 seconds. Talk about stress on components! And this heat doesn't really have too far to go, so back to back 1/4 mile runs? Sheesh.

For another example, check out data I pulled from my P85D showing a ~100V sag under full acceleration at 1300A. That means 130,000 W of heat being generated. 130,000W of heat! And you're worried about 900W of heat... In my 5 second run I generated the same waste heat as a 900W loss running for over 10 minutes. I mean, these are stresses I subject my P85D to all the time, as I'm sure many others do. Really, supercharging is tame compared to heavy acceleration and such. At 1000A+ we're talking measurable physical stress on wiring and such. At 300A, not so much.

Sure there is a chance that something came loose or wasn't installed correctly, or whatever. But, given that this is an older vehicle that's been on the road for several years and hadn't had an issue until yesterday... I'm going to defer to Occam's razor or other similar logic for now and just figure it's something much more obvious.

That's 130kW of power dissipated for a short amount of time in a cooling system which can withstand it vs an oxidised/bad connection point which cannot safely dissipate the power possibly igniting nearby flammable materials. Perhaps a hot HVJB could start a fire in the rear seat materials--what requirements are there for flame/heat resistant materials in automotive environments?

I think a HVJB fault is quite possible given Tesla has to remove connections from it to replace the drive unit. If a technician incorrectly loosened a bolt in the SpC circuit (DC charger path) that might be all that's needed.

Also, if I were to offer an additional possibility, it is odd that the rear hatch appears to be open. Could a jammed liftgate motor trigger a fire? What if the system fuse was incorrectly replaced?

 

[jhm]

I think the depth of price reaction to this fire will depend mostly on the willingness to buy and not panic sell on any overreaction. One or 2% would make sense as a short term response. If it goes much lower than that, tough minded longs can snap up shares at a discount.

Here's how I see this resolving:

* Tesla clarifies what the cause of the fire was. If any fault of Tesla equipment, they have a fix.
* Tesla reassures the public that is is a 1 in x million charge event, which is far less risky than gas cars and fueling infrastructure.
* Tesla reassert promise to cover battery fire damage and extends this to use of Tesla charging equipment. The customer gets a new Model S as a replacement vehicle.

With this kind of response, Tesla actually gains credibility and positive PR. Certainly all automakers face fire risks, but Tesla is the only one that will replace your car in the event of a fire originating from Tesla equipment. I doubt any other automaker could afford to stand behind their product in this way. So it is a way for Tesla to differentiate itself and build brand loyalty.

So after this plays out, Tesla is better off, and attention goes to Model X deliveries and other developments.

 

[ggr]

That's 130kW of power dissipated for a short amount of time in a cooling system which can withstand it vs an oxidised/bad connection point which cannot safely dissipate the power possibly igniting nearby flammable materials. Perhaps a hot HVJB could start a fire in the rear seat materials--what requirements are there for flame/heat resistant materials in automotive environments?

I think a HVJB fault is quite possible given Tesla has to remove connections from it to replace the drive unit. If a technician incorrectly loosened a bolt in the SpC circuit (DC charger path) that might be all that's needed.

Also, if I were to offer an additional possibility, it is odd that the rear hatch appears to be open. Could a jammed liftgate motor trigger a fire? What if the system fuse was incorrectly replaced?

So I must be misunderstanding something here. Yes, 130kW of power went somewhere. But the car was under full acceleration. Surely most of it went into kinetic energy, not heat?

 

[tom66]

So I must be misunderstanding something here. Yes, 130kW of power went somewhere. But the car was under full acceleration. Surely most of it went into kinetic energy, not heat?

Under peak acceleration ~400kW goes to wheels, the rest gets dissipated as heat in various parts of the vehicle (battery, cabling, inverter, motor, etc.)

This heat must be removed by the cooling system consisting of the radiator and pair of evaporators. The size of the battery gives it high thermal capacity, as well.

 

[Yggdrasill]

So I must be misunderstanding something here. Yes, 130kW of power went somewhere. But the car was under full acceleration. Surely most of it went into kinetic energy, not heat?

The 130 kW is only the extra heat generated in the battery and cabling. The energy that went into the inverter was 1300A x ~290V = 377 kW. The waste heat is (390V - 290V) x 1300A = 130 kW.

 

[MitchJi]

I'm pretty sure we'll see increased short interest again (as well as skewed put/call pricing toward expensive puts).

Does not happen except rarely and very briefly.
Understanding Put-Call Parity | The Options & Futures Guide

Understanding Put-Call Parity

Put-call parity is an important principle in options pricing first identified by Hans Stoll in his paper, The Relation Between Put and Call Prices, in 1969. It states that the premium of a call option implies a certain fair price for the corresponding put option having the same strike price and expiration date, and vice versa. Support for this pricing relationship is based upon the argument that arbitrage opportunities would materialize if there is a divergence between the value of calls and puts. Arbitrageurs would come in to make profitable, riskless trades until the put-call parity is restored.

 

[FluxCap]

We need delivery numbers released Sunday, I think.

 

[wk057]

This wasn't a P85D, this was an S85. And whether or not the heat generation is problematic or not depends entirely on the distribution and duration of the heat. 130 kW can be fine, while 100W can be problematic.

I'm certainly not saying it definitely was the HVJB. I'm just saying that if you assume this is the fault of the Tesla, the HVJB is the likely culprit. It could just as easily be the case that something caught fire in the trunk, or something similar.

Try to assume that this was the fault of the Tesla - where do you think the fire started and how?

I think there is your issue. Why is anyone assuming anything? I won't assume that this is the fault of the car. That's stupid. I'll go based on the evidence presented, which is completely inconclusive and insufficient to make such a judgement. I can, however, use my knowledge of the vehicle and components to presume that it most likely was NOT the fault of the car.

For the record, there are no significant HV wiring differences between an S85 and the 60/70/70D/P85/85D/P85D/S90/S90D/P90D with the obvious exception being the branch curcuit to the front motor on the D models. The sizing of the common cables and components are the same on all of them.

That's 130kW of power dissipated for a short amount of time in a cooling system which can withstand it vs an oxidised/bad connection point which cannot safely dissipate the power possibly igniting nearby flammable materials. Perhaps a hot HVJB could start a fire in the rear seat materials--what requirements are there for flame/heat resistant materials in automotive environments?

So I must be misunderstanding something here. Yes, 130kW of power went somewhere. But the car was under full acceleration. Surely most of it went into kinetic energy, not heat?

Under peak acceleration ~400kW goes to wheels, the rest gets dissipated as heat in various parts of the vehicle (battery, cabling, inverter, motor, etc.)

This heat must be removed by the cooling system consisting of the radiator and pair of evaporators. The size of the battery gives it high thermal capacity, as well.

The 130 kW is only the extra heat generated in the battery and cabling. The energy that went into the inverter was 1300A x ~290V = 377 kW. The waste heat is (390V - 290V) x 1300A = 130 kW.

Yes, the total power usage from the batteries is the power actually usable plus the power wasted as heat.

I think you guys severely overestimate the capability of Tesla's cooling system. In no way shape or form can it just get rid of 130 kW of heat. It can mitigate the temperature rise a little, and slowly bring it back down after it rises, but it doesn't have a 500,000 BTU cooling system to cope with such things. The same thing with supercharging. The car's cooling system just slows the temperature rise in the pack and components. It doesn't prevent it. A bit OT, but this is part of the reason for the taper in charge speed as the charge progresses to slow the release of heat within the pack to maintain a max temp set point since the cooling system can't keep up.

I think a HVJB fault is quite possible given Tesla has to remove connections from it to replace the drive unit. If a technician incorrectly loosened a bolt in the SpC circuit (DC charger path) that might be all that's needed.

This is false. All high voltage connections needed for replacement of the drive unit are outside/under the vehicle and are basically quick disconnects. No bolted connections needed and nothing near the fast charge equipment is touched.

Also, if I were to offer an additional possibility, it is odd that the rear hatch appears to be open. Could a jammed liftgate motor trigger a fire? What if the system fuse was incorrectly replaced?

*shrugs* Seems like we're stretching here.

Overall, I see nothing based on what we've seen from this publicly that can prove or disprove any fault of the car or charger. And again, based on everything I know about the car and components I find it much more likely that this is something unrelated to the car/charger.

 

[MitchJi]

Is this the 'official' short-term thread? It should be renamrd to "Short-Term TSLA Price Movements... ".

Eius primus cuius nominus. It SHOULD be named whatever the OP wants it to be named.

Unless a Mod jumps in and....

Oh. Lookee what I just did! :biggrin:

IMO a Mod should jump in and make it a sticky, and the 2015 version should be unstickied.

Happy New Year everyone.

Wishing everyone much happiness, good health, and prosperity in 2016!

Thank you all for being a great resource for TSLA investment information!

Best Wishes,

Mitch

 

[Scott Ales]

Google this: fire at gas pump

Click on Images.

or

fire at gas pump - Google Search

Take your pick!

 

[Yggdrasill]

I think there is your issue. Why is anyone assuming anything? I won't assume that this is the fault of the car. That's stupid. I'll go based on the evidence presented, which is completely inconclusive and insufficient to make such a judgement. I can, however, use my knowledge of the vehicle and components to presume that it most likely was NOT the fault of the car.

If you don't look at hypotheticals, it's hard to determine the various outcomes for TSLA.

For the record, there are no significant HV wiring differences between an S85 and the 60/70/P85/85D/P85D/S90/S90D/P90D with the obvious exception being the branch curcuit to the front motor on the D models.

Aside from the inverter, you mean. How many amps does the S85 pull, again?

I think you guys severely overestimate the capability of Tesla's cooling system. In no way shape or form can it just get rid of 130 kW of heat. It can mitigate the temperature rise a little, and slowly bring it back down after it rises, but it doesn't have a 500,000 BTU cooling system to cope with such things. The same thing with supercharging. The car's cooling system just slows the temperature rise in the pack and components. It doesn't prevent it.

There's little need to remove the 130 kW. We're talking about a very short amount of time, so not much energy at all, and most of it is soaked up by the 600 kg of mass in the battery pack.

 

[jhm]

Anybody need this?

 

[tom66]

This is false. All high voltage connections needed for replacement of the drive unit are outside/under the vehicle and are basically quick disconnects. No bolts needed and nothing near the fast charge equipment is touched.

I don't yet own a Tesla, so I can't confirm. But, from the pictures I've seen there are no quick-release style connectors (which incidentally would serve as a possible fire source if they did exist) and ultimately everything on the high-current HV side is bolted in somewhere. (With AC compressor/battery heater/etc being connector mated.) So there will be bolts that have to be secured/removed. And if it's not the HVJB, perhaps the charge port, as that is certainly bolted in, which would explain why the fire occurred during supercharging and not under acceleration.

http://www.teslamotorsclub.com/attachment.php?attachmentid=57540&d=1408992869

As for speculation -- I don't see any harm myself. People shouldn't take what's said on here as the official diagnosis but it would be nice to hear what other engineers on this forum think the fault cause would be. I actually doubt Tesla will be very specific as to the fault cause if little PR is generated so this may be all we get.

 

[wk057]

If you don't look at hypotheticals, it's hard to determine the various outcomes for TSLA.

Aside from the inverter, you mean. How many amps does the S85 pull, again?

There's little need to remove the 130 kW. We're talking about a very short amount of time, so not much energy at all, and most of it is soaked up by the 600 kg of mass in the battery pack.

I've actually concluded that the inverters are pretty much identical, component wise. Software limits the current allowed by the various models. There might be some binning happening with the performance vs non-performance versions, but physically they're the same. One day I may fully test this by forcing an S85 to accept P85 firmware, but that's a tale for another day.

We'll have to just agree to disagree on the significance of heat build up in various components I guess, which is unfortunate since my data is based on the actual components and real data, and your assertions are based on.......... trying to pin this fire on Tesla.

- - - Updated - - -

I don't yet own a Tesla, so I can't confirm. But, from the pictures I've seen there are no quick-release style connectors (which incidentally would serve as a possible fire source if they did exist) and ultimately everything on the high-current HV side is bolted in somewhere. (With AC compressor/battery heater/etc being connector mated.) So there will be bolts that have to be secured/removed. And if it's not the HVJB, perhaps the charge port, as that is certainly bolted in, which would explain why the fire occurred during supercharging and not under acceleration.

Oh come on. I've personally dropped a rear drive unit from a Model S. I assure you the HV connection is not a bolted junction.

 

[tom66]

Oh come on. I've personally dropped a rear drive unit from a Model S. I assure you the HV connection is not a bolted junction.

That is useful information then - as I said I do not own a Tesla so I would defer to you on that. So what type of connector is it out of interest?

 

[wk057]

That is useful information then - as I said I do not own a Tesla so I would defer to you on that. So what type of connector is it out of interest?

I can't seem to find any of my personal photos from back then, but here is a crappy quality one I found elsewhere:

 

[tom66]

That's interesting it looks like it has an outer shield for monitoring insulation faults to the inverter casing. I have seen that in some industrial system before.
Don't try and reverse red and black. Must put a small crater in the inverter IGBTs.

 

[wk057]

That's interesting it looks like it has an outer shield for monitoring insulation faults to the inverter casing. I have seen that in some industrial system before.
Don't try and reverse red and black. Must put a small crater in the inverter IGBTs.

Yeah, as I mentioned in one of my earlier posts in this thread all of the HV wiring in the Model S has shielding and double insulation to detect faults in the wiring.