Two bits are completely non-sensical to me, is there any battery technician or otherwise knowledgeable person that can indicate in what conditions this makes any sense?
> Beginning early in the morning of my second day with the car, after the projected range had dropped precipitously while parked overnight, I spoke numerous times with Christina Ra, Tesla’s spokeswoman at the time, and Ted Merendino, a Tesla product planner at the company’s headquarters in California. They told me that the loss of battery power when parked overnight could be restored by properly “conditioning” the battery, a half-hour process, which I undertook by sitting in the car with the heat on low, as they instructed. That proved ineffective; the conditioning process actually reduced the range by 24 percent (to 19 miles, from 25 miles).
If there is one thing that will use up large amounts of energy it is electric heating, I find it hard to believe that using a heater as a consumer would regenerate the battery capacity in excess of what the the heater is consuming unless most or all of the energy was directed at the batteries. The exterior of a car will drain heat energy about as fast as you can put it in under cold conditions (or faster...).
> It was also Tesla that told me that an hour of charging (at a lower power level) at a public utility in Norwich, Conn., would give me adequate range to reach the Supercharging station 61 miles away, even though the car’s range estimator read 32 miles – because, again, I was told that moderate-speed driving would “restore” the battery power lost overnight. That also proved overoptimistic, as I ran out of power about 14 miles shy of the Milford Supercharger and about five miles from the public charging station in East Haven that I was trying to reach.
That does not make any sense either. Any kind of consumption will ultimately reduce the available range, you don't restore by removing joules from a pack.
I've lived in a house powered with batteries, solar and wind for a long enough time to know that indeed temperature affects battery capacity, sometimes dramatically. But consuming power under cold conditions never put energy back in. Is this different for the kind of batteries that the Tesla uses?
Or is the 'Tesla said' claim just an effort to get out from under the apparently non-sensical decisions that were made here?
Or are Tesla spokespeople and product gurus totally clueless (which would seem to be very hard on the imagination)?
All the hard data from the Tesla logs except for the 'shutdown' is contradicted by words apparently spoken (and probably unverifiable except for 'he said/she said' style debate) rather than actually refuting the data.
> That does not make any sense either. Any kind of consumption will ultimately reduce the available range, you don't restore by removing joules from a pack.
I think what is happening is that he thinks the battery actually does have the charge, but the estimate is incorrect because of the cold. What he thinks is going to happen by driving is that the battery will heat up and become more efficient, and the estimated range will raise.
I do not find this an unreasonable mental model, even if it does or does not represent the actual workings of a battery-powered vehicle.
That seems to be plausible explanation, but I don't see how you give such advice to somebody on the road. You have two potential situations:
1. Battery has lost some charge for unknown reason, and has to be recharged.
2. Battery has proper charge, but the estimate is wrong.
If you act according to true scenario, client is happy in both cases. If true scenario is 2 but you act like it's 1, the client wastes and hour to recharge (which isn't necessary) but arrives at the goal. If true scenario is 1 but you act like it's 2, the client is stuck in the middle of the road and curses you.
Clearly, you should always choose to act as if the true scenario is 1 and recommend proper recharging, and try to debug why charge indicator was potentially wrong later. If the support person gave different advice, he was setting himself and his company for the mess up, and the mess up ensued.
"If the support person gave different advice, he was setting himself and his company for the mess up, and the mess up ensued."
This is why we need the call logs. And I fully suspect Tesla records them, so the fact that it wasn't released may suggest that Broder's account was indeed correct
Why should they? They were just reps on the phone talking to a guy who was reviewing superchargers, not planning for a media battle. I don't see how they would have prepared for anything other than the standard advice and it would be surprising if they did.
While the whole discussion makes me skeptical of both Broder and Tesla's customer service, I'd like to add here that Tesla most probably would need permission to do that. Even releasing GPS data is already a questionable move - IANAL, but I believe in Europe this would be pretty much unthinkable, except if he gave explicit permission on paper first (general agreement terms probably wouldn't be enough, because of the surprising nature of such a term).
This would be a more significant concern if he was driving his own car, but since it's a Tesla owned review model, I'm sure they have legal rights to it. In addition, given their past troubles with Top Gear I wouldn't be surprised if Tesla wrote it into a review agreement.
> .., but since it's a Tesla owned review model, I'm sure they have legal rights to it.
I doubt that. Say, you lend a car to your friend and let the navigation system log his/her route. The route includes compromising information about work related issues. Even the logging itself is questionable, but then releasing that information to the public - boy, I'd sure check my lawyers first.
As I understand, the 'European sensor' for privacy tingles at quite different levels than the US American one.
Ah, but you're overlooking the extremely strong possibility that the contract Broder / NYT signed as part of borrowing the test vehicle authorized Tesla to use the onboard telemetry in any way Tesla sees fit.
Furthermore, this situation is extremely dissimilar to a private individual lending a car to another private individual to do things where the borrower has a reasonable expectation of privacy.
If he was directly calling a person at Tesla it would be unlikely to be recorded. If he went through the normal customer support number - you'd expect it to have been recorded after the "This call may be recorded for training purposes etc" intro
This is very true and it's a well known customer service approach. That's why the guy taking your pizza delivery order tells you it will be 45 minutes even though it only takes 5 minutes for them to make a pizza.
While the battery does have internal coolant (heat-exchange) loops, it's position on the bottom of the car (it's the entire floorpan) means that it has a large surface area exposed to the weather, and wind-chill would rapidly draw any internal heat away. The question that I don't know the answer to is: how rapidly?
"Never attribute to malice that which is adequately explained by stupidity."
You know, i like a conspiracy theory as much as the next guy, but this seems like a genuine series of errors, intentional or not, who knows.
But, let me play a separate angle to this, which is that when I read this article, I immediately flash-backed to all the tech support calls i'd had with relatives where each of us made some mistake or made some assumption given the facts at hand. "turn down the brightness, stop using the cd drive, turn off bluetooth, limit wifi usage, oh, wait, it's plugged in? ummm... time for a new power supply then!"
I don't know why we should expect the 'average consumer' to have deep insight into the workings of batteries or electric car technology. This stuff remains new and I think the point to be gained from this article is that it's still not totally obvious what causes some failures and not others. It'd be one thing if this guy really tore into Tesla, but he seems ambivalent more than anything else.
And reading that is basically the same reaction i get from my mom about my iphone: it's nice, but it's confusing to me and i still make mistakes each time i use it—nice, but not for me.
All our tech makes some assumptions about what you know and the effort you're willing to expend to get something to work. I don't think it's entirely unreasonable to step back and say "hey, something didn't work out and maybe that's a failure of the interface or our messaging or something" rather than jumping to claims of journalistic fabrication and oil conspiracies.
Looking at the plots from Musk's blog post, the battery state of charge diminishes a bit overnight, but the estimated range diminishes much more. Presumably because a cold battery has a shorter range. As the battery warms up, the estimated range should go up as well.
How much the range goes up probably depends on how much the battery warms up; in the cold morning weather in Norwich, the battery may have warmed up less than the Tesla people were expecting.
I drove a honda civic hybrid in Northern Ontario for two winter seasons. The batteries where NiMh and the cold was absolutely brutal on them. Indeed they'd recover a bit of charge when warmed up but it was usually very hard to tell if that was because of the engine running or because the batteries warmed up. (and sometimes even harder to tell because the displays wouldn't work at all below -25 celsius).
Maybe the batteries Tesla uses recover better/faster but since it's all electric there is obviously no way to get more power into the pack so the only thing that using a heater will do is drain it, and it will drain it pdq. If I was driving an all electric car and I was worried about my range the one thing you can be sure of is that I would maintain as constant a speed as possible and the heat would be off. After all it is a lot better to arrive at your destination cold than it is to deplete you battery and spending even more time in the cold.
I'm pretty sure Tesla knows the exact power curves for their batteries at any temperature condition that could realistically speaking occur, if they were asleep at the switch that's a big bad problem for them but if they had this info and used it and this is turning into a game of words rather than a game of data then the only thing they should do at this stage is to have a Tesla engineer duplicate the trip conditions to see what the result would be if you behaved rationally rather than irrationally.
That way we'd get some usable information. Experiments are only valid when you can repeat them.
This is not my area of expertise at all, but that sounds backwards.
As I understand it a given number of molecules' bonds can be broken at any point to generate current. In colder ambient temperature the propensity to generate current decreases. However, the quantity does not. In other words, the apparatus for measuring what "charge" is available will incorrectly judge how much is left, but an intelligent system on the other hand may also take into account what the ambient temperature is doing to the sensor of how much current flows given a certain test circuit.
I'd guess that there is not an objective way to measure the charge left. I'd also guess that at a colder temperature it might not have as much power or as much torque, but that it would not affect the range, especially if the battery if artificially (or intrinsically) warmed once it gets toward the "bottom" of its capacity.
What the support people could have been talking about is how to game the system so that the sensors report a more reasonable gauge of the true range. That means that the supposed decrease overnight was not that the potential energy dissipated, but that the colder temperature lead to less accurate readings. Causing a current draw through driving slowly in the parking lot and running the heater might cause the battery to heat up, and thereby affect the current available to a test circuit, something that matters to the sensors' test circuits.
I'd like to hear from someone who actually knows something about electrical engineering, but without being informed on the field, it looks like a failure of imagination in assuming good faith and imaging possible scenarios.
gratuitous analogy:
Let's say it is a fictitious 1975 where Porsche has remote telemetry, and a NYT reviewer is skeptical about oil-cooled engines, because he states that you may run a little low on oil then also be low on coolant or vice versa. In the early morning of a freezing day, he looks at the dipstick. It says he is a three or four quarts low! He calls support, and they tell him that he will have more oil if he warms up the engine, and he'll be able to go for a drive without hurting the engine. (They should have said that he would get a more accurate measurement rather than get more oil) So, he starts the car, revs the engine, drives in circles, etc. Maybe he checks the oil again, maybe not. He takes off, and a couple hours later the engine seizes up. Apparently, it was both looking like it was extremely low on oil and was also actually very low on oil. The telemetry shows the reviewer appearing foolish, and possibly trying to ruin the engine. You could say that he is a professional and should have been able to parse the statements from support more intelligently. Yet they both look bad, but it may not be an inaccurate depiction of what end users would experience.
I was speaking informally earlier, but if we make things more precise then I think we're pretty much on the same page.
I think you're right when you say:
>In colder ambient temperature the propensity to generate current decreases. However, the quantity does not.
Presumably, the car stops running when the battery's propensity to generate current ("voltage") falls below a certain threshold. If that propensity to generate current does decrease when it's cold, then a cold battery will hit that car-stopping threshold earlier, right? Assuming the battery stays cold.
That's all I meant when I said "a cold battery has a shorter range".
And when the battery warms up, its chemical reactions speed up, increasing the voltage and pushing the car-stop threshold into the future. That's what I meant by "As the battery warms up, the estimated range should go up as well."
The battery's "state of charge" in the plot from Musk's blog post does go down overnight. Whether that's due to self-discharge, some system in the car that used a bit of energy overnight, or some temperature-related measurement effect (or a combination of those things), I don't know. I just thought it was striking that the "estimated range" dropped so much more than the "state of charge" (at the 400 mile mark in Musk's plots).
If I were to speculate, and I am, I would guess that the variable here is the temperature of the battery packs. Batteries are chemical power sources, and the chemical reaction which frees up electrons has temperatures where it works, and temperatures where it doesn't. (Hence "cold weather amps" as a selling point on car batteries).
Anyway, I'd speculate that the Tesla person was thinking that if the battery got up to temperature it would go back to what it thought was the current capacity (as measured by open circuit voltage level).
I suspect something drained power from the car over night. In my case I've experienced power drain (non Tesla) from leaving an MP3 player plugged into the 'aux' jack of the center console. But we may never know for sure without better instrumentation.
The battery's heating system likely drained the power overnight. The battery pack must be kept above a certain temperature or it will become irreparably damaged.
Do you have a reference for that? I ask because while I can imagine there are limits the kinds of things I've not seen one for Tesla's battery packs. I see that typical LiOn type batteries have a 'one month at -20C (-4F)' sort of limit, car batteries are typically better than that, good to -40F or so.
Edit: This article http://electronicdesign.com/power/operating-conditions-get-t... says "permanent damage at -50 degrees C" which is way colder than the lower 48. It's a good thought though, and I'm sure if you were connected to the wall at night the car would heat the batteries to an optimal temperature. Just not sure why it might do that without power available.
What I've heard on this angle is that the Tesla maintains the batteries at a safe operating level overnight to enable the owner to drive at any time. They could implement a storage mode that allows the batteries to drop below operating temperature while staying above damage temperature, but their software does not yet do that.
Tesla has a bit of the Apple approach to software, where they intentionally limit the number of software options to not overwhelm the user. This may change as they continue development, but it's where they are now.
Mostly correct, but I remember standing outside my 5th grade classroom window waiting for the teachers to unlock the door. At that time the school doors were only unlocked prior to class starting if there were blizzard conditions, not for cold. The classroom had a thermometer on the window that read -50C at the time. The only reason I remember it was because it was the first time I realized -40C = -40F.
Hah - someone in the first HN discussion about this was complaining that it was unfair to complain about the Model S becoming less efficient at low temperatures because ICE cars did too, and as I recall his definition of low temperatures was -50C.
Or are Tesla spokespeople and product gurus totally clueless?
Not entirely, but if your product has a known (tiny) glitch, and a reporter calls up with something that sounds like that glitch, what are you going to do? One obvious choice is tell them it's a tiny glitch of no consequence and hope you're right. In the best case scenario (tiny glitch), responses like "Oh, dear, it sounds like our car is underperforming" leave a bad impression too.
Any kind of consumption will ultimately reduce the available range, you don't restore by removing joules from a pack
It's entirely possible that the amount of energy you can get out a battery depends on its current temperature, and that by sitting around to let it slowly warm up, the total power you can get out of it would be faster than if you tried to pull it all out as fast as possible.
Sure it is. But that will only work when you warm up the pack, not when you warm up the car. The draining of energy will also warm up the pack (it should, to some extent because the pack will have an internal resistance which the current passes through, which will turn into heat) but this is still much less efficient than using that energy to propel the car forward.
The band where draining at a lower rate would warm up the battery to the point where the aggregate power taken from the pack would be higher if you drained it at a lower rate for a 1/2 hour and then at a higher rate is a very thin one if it exists at all.
The good news is that that is a thing that could easily be proven or disproven with a bunch of LiPo batteries, a freezer and a bunch of resistors.
I'd be quite surprised if the Ri of the batteries was low enough to allow sufficient current to flow, yet high enough to heat up to have this effect.
A car in motion uses ten times the power of a house. The engineers apparently wanted him to slowly pull power from the battery, which would be consistent with "sitting in the car with the heat on low."
If it turns out Tesla denies telling him how he can condition the battery, that would be significant.
Musk already flatly denied that he had ever been "cleared" by Tesla for the next leg of the journey. Somebody's wrong.
> The final leg of his trip was 61 miles and yet he disconnected the charge cable when the range display stated 32 miles. He did so expressly against the advice of Tesla personnel and in obvious violation of common sense.
It would be interesting too to see the rates of power consumption for the model S at cruising speed and the 'heat on low'.
From what I remember (doing some electric car design a long time ago) a car that is cruising at about 50 miles per hour uses < 10KW, and that was 1980's car, I'd expect the Tesla to do a little bit better than that.
> If it turns out Tesla denies telling him how he can condition the battery, that would be significant.
It would be, and on top of that they could prove in a re-run that that was what did in the trip (and starting out on a leg with less range than the leg was long, that bit did not make sense at all in the previous article).
> If there is one thing that will use up large amounts of energy it is electric heating, I find it hard to believe that using a heater as a consumer would regenerate the battery capacity in excess of what the the heater is consuming unless most or all of the energy was directed at the batteries.
If temperatures are low and if the charging station can deliver more power than the batteries need to charge up, then using the heater may warm up the battery pack and allow it to charge more efficiently, then discharge more efficiently after leaving the station.
When batteries are cold, they neither charge nor discharge efficiently. Batteries benefit from higher temperatures (but not too high, as the recent Boeing Dreamliner battery story reveals).
> All the hard data from the Tesla logs except for the 'shutdown' is contradicted by words apparently spoken (and probably unverifiable except for 'he said/she said' style debate) rather than actually refuting the data.
If they did it through regular customer service, would it have been recorded? I suspect not or else the evidence would have been trotted out already.
>>Or are Tesla spokespeople and product gurus totally clueless (which would seem to be very hard on the imagination)?
No, its not hard to imagine this and might even be true. Middle managers know little apart from running daily affairs.
Its very much possible that when faced with questions they have no answers to they might have imagined a analogous set up(ordinary fuel car) and apply the question to such a thing and seek answers.
When you make uninformed guesses in the wild especially about new things, you generally make colossal mistakes- that is what seems to have happened here.
> I was given battery-conservation advice at that time (turn off the cruise control; alternately slow down and speed up to take advantage of regenerative braking)
Someone failed at basic thermodynamics. Converting electricity to mechanical and back to electricity causes a terrible loss in power.
That a New York Times journalist would fabricate data in an automobile review in order to wage war on the electric car industry seems beyond belief as well. We really don't have enough info to resolve these discrepancies, but Occam's Razor suggests to me that John Broder legitimately believes his claims and Elon Musk believes Broder to be a liar. One or both of them has incorrect data. It seems unlikely that either is deliberately lying.
Point 4 of this article suggests that accelerating in short bursts with long coasts in between works best for gas-powered cars. I can see how turning off cruise control could be more efficient in this case too, although I agree braking would be silly. http://www.mrmoneymustache.com/2011/07/26/hypermiling-expert...
No it doesn't. What the article says is to keep your velocity constant = zero acceleration by coasting and giving gas in short spurts. But it's entirely possible that journalists don't know the difference between "giving gas" and "accelerating the car."
I don't think the pulse and glide method keeps your velocity constant. The idea is that accelerating to 70mph and coasting down to 50mph repeatedly is more efficient than maintaining a constant speed of 60mph. Not always more practical, but you should try to drive that way when you get a chance. Here's another explanation: http://www.metrompg.com/posts/pulse-and-glide.htm
All the hard data from the Tesla logs except for the 'shutdown' is contradicted by words apparently spoken (and probably unverifiable except for 'he said/she said' style debate) rather than actually refuting the data.
Is it? The Tesla temperature chart makes a big thing about temperatures at a very specific point, ignoring that not much further in the journey the temperature dropped to the minimum for 50 miles. The infamous "32 mile" charge also shows that when the car was parked for the night it has 90 miles of range, disappearing overnight. Or complaining that he didn't know about a charge station that the car itself didn't know about.
Further, "hard data" is a bit of a stretch. No one but Tesla has the raw data, and they've carefully presented selective bits of it for maximum impact, which is naturally given that they're incredibly biased. Such as the "drove around a parking lot trying to kill the car" bit, when it was actually just five minutes looking for a unlit, unmarked charge station. It's also humorous that they take their telemetric speeds as gospel, when vehicle speedometers are notoriously unreliable.
The answer is very simple: Brody is lying about what Tesla told him, just like he's told many other lies in his article and in the rebuttal.
Putting it into a "he said / she said" is a smokescreen.
The car might be a lemon but the idea that Tesla told him to run the heater to charge the battery is beyond credulity.
This is not exactly the first time the NYT has told lies for ideological reasons. The paper does it regularly, and really, the idea that it (or any paper in america) is an "unbiased" media is quaint.
The difference is, Elon Musk is willing to stand up to them and call them on it, so they are obfuscating.
Elon Musk has a billion dollars riding on calling the NY Times a liar and discrediting them.
Here's the thing though: the problem with the Tesla battery is the same problem that every other EV to date has had in sub-zero weather: they lose their charge and the charging meter gets decalibrated.
Tesla's bane is not a biased NY Times reporter. Their fundamental mistake was giving an EV to the NY Times to test drive in the middle of one of the coldest winters on record.
EDIT: Also one of the warmest winters on record in that area of the country, but not during the period of the NY Times' test.
I agree, The NYT has global influence and like you say TESLA is in a sink or swim situation.
But I have to ask this: doesn't is take some 30-years to get a technology completely figured out and completely usable with no hassles or bugs and could Tesla be entering the second decade of that process? You mentioned the cold weather and that is definitely a valid consideration that has to addressed.
To use the web as an analogy, it took 12-years to create, 4-years to grow and produce a web-browser. 3-more years to commercialize and another 10-years to become part of everything we do.
With that in mind, perhaps TESLA is reluctant to admit that they are just in the "browser creation" stage and they still have work to do?
Good thing Musk is willing to "stand up to them" given that he's the truly unbiased one in this situation, right? He's playing an angle here too. And the other article (http://www.theatlanticwire.com/technology/2013/02/elon-musks...) casts some doubt on his loud protestations. And they've only released their summarized charts, not the raw log data, anyway. It's already a "he said / she said" situation, it's just that much of the HN crowd is more apt to be on one side vs. the other.
> it's just that much of the HN crowd is more apt to be on one side vs. the other.
I don't think so, it's just that one part of the HN crowd likes data more than 'someone said'.
So now it is up to Tesla to provide even more data, preferably with an exact re-run of the conditions in the presence of said journalist. That should clear up any kind of difference and would establish whether or not there is either a bug in the system, a bug in the procedures or a systemic problem with the car. If the problem can't be reproduced with proper handling of the car then there should be a retraction. Regardless of which it is the bickering should stop.
The whole thing hinges on whether you're stupid enough to leave Norwich without sufficiently charging.
Do the same run a hundred more times, and nobody will fail as long as they exercise that basic amount of care. In that sense, reproduction is pointless. We already know the result, within a margin of error.
I just don't think that's fair. If Tesla Engineers tell you "an hour's charge will bring the battery back" then I think many people would just take that at face value.
HN has a deeper problem. I don't think the entire crowd is biased, but due to the karma system a few people have louder voices (their posts show up at the top and stay there for a long time, even when they aren't the best responses). Some of those people are very opinionated and their opinions happen to be sticky. The algorithm should change.
On the other hand, Brody has known record of exaggeration and distortion of truth. Whereas Musk is an honest, no-nonsense engineer. (Although I'd be interested if you could point me to a situation where Musk was caught blatantly lying about something.)
If that is that case, Musk would have known about his alleged "agenda" before handing over the keys for the review and could have acted accordingly. But he didn't.
I don't think Musk has the time to do background checks on every media person who wants to test-drive a vehicle. And the supposedly credible reputation of NYTimes may also have led him to trust Broder. In his blog post however he admits that he made a mistake there.
>> Good thing Musk is willing to "stand up to them" given that he's the truly unbiased one in this situation, right?
Fair enough, but let's not pretend that now that this reporter is in the spot light for possibly fabricating a story, his career isn't on the line. He (also) has every incentive to be extremely unbiased in his own defense.
They'll have a good chuckle at the NY Times (and even Fox would have a laugh) when they see you're accusing them of attacking alternative energy for ideological reasons.
> Beginning early in the morning of my second day with the car, after the projected range had dropped precipitously while parked overnight, I spoke numerous times with Christina Ra, Tesla’s spokeswoman at the time, and Ted Merendino, a Tesla product planner at the company’s headquarters in California. They told me that the loss of battery power when parked overnight could be restored by properly “conditioning” the battery, a half-hour process, which I undertook by sitting in the car with the heat on low, as they instructed. That proved ineffective; the conditioning process actually reduced the range by 24 percent (to 19 miles, from 25 miles).
If there is one thing that will use up large amounts of energy it is electric heating, I find it hard to believe that using a heater as a consumer would regenerate the battery capacity in excess of what the the heater is consuming unless most or all of the energy was directed at the batteries. The exterior of a car will drain heat energy about as fast as you can put it in under cold conditions (or faster...).
> It was also Tesla that told me that an hour of charging (at a lower power level) at a public utility in Norwich, Conn., would give me adequate range to reach the Supercharging station 61 miles away, even though the car’s range estimator read 32 miles – because, again, I was told that moderate-speed driving would “restore” the battery power lost overnight. That also proved overoptimistic, as I ran out of power about 14 miles shy of the Milford Supercharger and about five miles from the public charging station in East Haven that I was trying to reach.
That does not make any sense either. Any kind of consumption will ultimately reduce the available range, you don't restore by removing joules from a pack.
I've lived in a house powered with batteries, solar and wind for a long enough time to know that indeed temperature affects battery capacity, sometimes dramatically. But consuming power under cold conditions never put energy back in. Is this different for the kind of batteries that the Tesla uses?
Or is the 'Tesla said' claim just an effort to get out from under the apparently non-sensical decisions that were made here?
Or are Tesla spokespeople and product gurus totally clueless (which would seem to be very hard on the imagination)?
All the hard data from the Tesla logs except for the 'shutdown' is contradicted by words apparently spoken (and probably unverifiable except for 'he said/she said' style debate) rather than actually refuting the data.