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Tesla Model S Battery Drain Issue Fixed

Soulskill posted about 4 months ago | from the acquitted-on-all-charges dept.

Power 239

cartechboy writes "Does the Tesla Model S suck down power even when the car is switched off? Recently, a tweet to Elon Musk with an article saying so sparked the Tesla CEO's attention. He tweeted that it wasn't right and that he'd look into the situation. Then a few hours later, he tweeted that the issue had to do with a bad 12-volt battery. Turns out Tesla had already called the owner of the affected car and sent a service tech to his house to replace that battery — and also install a newer build of the car's software. Now it appears the 'Vampire Draw' has been slain. The car went from using 4.5 kWh per day while turned off to a mere 1.1 kWh. So, it seems to be solved, but Tesla may either need to fix some software, or start sending a few new 12-volt batteries out to the folks still experiencing the issue."

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239 comments

And, Folks, stay tuned.. (2)

Anonymous Coward | about 4 months ago | (#45621073)

..for Elon's next Slashvertisment.

Re:And, Folks, stay tuned.. (1)

Anonymous Coward | about 4 months ago | (#45621113)

" to a mere 1.1 kWh per day, while doing nothing.."

- sorry, I am actually a Tesla fan (or would be, given the chance..) - but 1100w (per day) for doing sweet fuck all, presented as progress?

it's stuff like this that makes me say, thanks, call me when you have the finished article.

Re:And, Folks, stay tuned.. (2)

TechyImmigrant (175943) | about 4 months ago | (#45621139)

No, that 1100w per day. That would be an increasing rate of power draw.

1100Wh per day. So a draw of 1100/24 W = 45.83W.

Re:And, Folks, stay tuned.. (0)

Anonymous Coward | about 4 months ago | (#45621199)

..fair enough reply, still a lot for nout tho..

I dunno, I really would like to live in aworld whereby I can switch things 'off'.

Then on again, and they still work. Do you use a car everyday? I don't. I would ask for some 'real-life' experience from Telsa drivers, how this all works it out.

However, tis the internet ;) I know exactly what I'd get on here if I did. Sadly.

Re:And, Folks, stay tuned.. (5, Informative)

von_rick (944421) | about 4 months ago | (#45621443)

Wan't to completely turn the battery off? You sure can, but that clicker to open/lock the door won't work, nor would the security alarm. These are the first two things that come to mind. There might be many other essential things that you might have to do without.

Re:And, Folks, stay tuned.. (3, Insightful)

TechyImmigrant (175943) | about 4 months ago | (#45621483)

For 45W? That's a lot of watts for a 15mA receiver.

 

Re:And, Folks, stay tuned.. (1)

von_rick (944421) | about 4 months ago | (#45621665)

The AC comment mentioned tunring everything completely off. There must be some documentation that gives the breakdown of where all the 45W end up. But expecting to turn all the electronics OFF in a present day automobile is not the smartest of ideas.

Re:And, Folks, stay tuned.. (5, Funny)

fahrbot-bot (874524) | about 4 months ago | (#45622087)

But expecting to turn all the electronics OFF in a present day automobile is not the smartest of ideas.

For sure the clock would be wrong - and just flash 12:00 all damn day :-)

Re:And, Folks, stay tuned.. (1)

mrchaotica (681592) | about 4 months ago | (#45621755)

Do you use a car everyday? I don't.

Then you're not the market for a Tesla. Not only because batteries degrade over time (whether you're using them or not, I think), but also because if you only use a car occasionally then it's stupid for you to buy an expensive car.

Re:And, Folks, stay tuned.. (0)

Anonymous Coward | about 4 months ago | (#45621919)

..ah, fuck - OP AC (again..) - while I was actually trying to stay out of this now, this is so completely fucking stupid a reply, I can't resist.

OK, again, Do You Know Anybody Who Uses A Car EVERYDAY? (sorry, my blink tag is broken..)

I don't either, because they don't exist.

I do, however, happen to know people, like myself, who may well be interested in such an 'expensive' vehicle (my current car is a BMW7) , bur also have some real-life issues, like weekend homes, where they like to switch the power off, completely, streets in cities where they like to park for more than a few days without a handy power socket, etc.

I remain unconvinced, 1100w (per day - which I call when no one else does ;) is too much, it remains however admittedly an improvement over an apparently previous 4.5 kWh draw per day, which they were apparently shipping on production models. That, my friends, is a fucking *insane* power draw for an unused vehicle, seriously.

Re:And, Folks, stay tuned.. (4, Informative)

von_rick (944421) | about 4 months ago | (#45621163)

" to a mere 1.1 kWh per day, while doing nothing.."

- sorry, I am actually a Tesla fan (or would be, given the chance..) - but 1100w (per day) for doing sweet fuck all, presented as progress?

it's stuff like this that makes me say, thanks, call me when you have the finished article.

1.1kWh is equivalent to having a ~40W light bulb on. If you have a couple of circuits powered on, given it is a fully electric car with all kinds of gizmos built into it, this discharge rate is actually quite nominal.

Re:And, Folks, stay tuned.. (-1)

Anonymous Coward | about 4 months ago | (#45621315)

The better question is why is there power drain at all? The point of turning something off is that it is no longer on. If it's still on while it's off, then it's not really off. So why can we "turn it off"?

For being praised as such an amazing genius, Elon Musk sure has a reputation for not-quite-doing what he sets out to...in a very business-man-wants-to-get-paid-but-doesn't-care-about-doing-it-right kind of way...

Re:And, Folks, stay tuned.. (5, Interesting)

Grishnakh (216268) | about 4 months ago | (#45621351)

Actually, it's shockingly high. I'm a Tesla fan, but this seriously makes me wonder what's eating up all that energy while the car is supposed to be "off".

The Tesla is not the only car out there with "all kinds of gizmos built into it": every high-end luxury car, from the likes of Mercedes, BMW, Cadillac, etc., is loaded with electronic accessories. However, all those cars run on gasoline engines, with a standard 12V battery to keep things alive when the car is "off". No regular car would be able to start its engine in the morning if it were powering a 40W light bulb all night.

So what exactly is the Tesla doing with all that power? Even if it's keeping a WiFi connection alive, that shouldn't take much power: my little smartphone can do that for days with a puny little 5.6Wh battery. Are they running the main computers at full power? It really shouldn't be that hard to put them into sleep states when the car is off. It sounds like maybe they badly architected the computers in this car, so that they could never go into power-saving sleep states and still keep the WiFi/3G connection alive, something every modern smartphone can do with ease.

Re:And, Folks, stay tuned.. (0)

Anonymous Coward | about 4 months ago | (#45621557)

Yep, rather weird.
Self discharge on the main battery should be on the order of 9W.
And yeah, I also suspect the mystery draw is the main computers.

Re:And, Folks, stay tuned.. (1)

Grishnakh (216268) | about 4 months ago | (#45621983)

Self discharge on the main battery should be on the order of 9W.

I started thinking about that after I wrote the previous comment, so this answers my question assuming your number is correct. A big-ass battery pack like the Tesla's surely has a significant self-discharge rate, but 9W isn't too bad, and sounds about right considering how fast my cellphone batteries self-discharge (I have spares I keep for days when I'll be using my phone a lot and won't have access to a charger).

Re:And, Folks, stay tuned.. (1)

AmiMoJo (196126) | about 4 months ago | (#45621635)

It sounds like maybe they badly architected the computers in this car, so that they could never go into power-saving sleep states and still keep the WiFi/3G connection alive, something every modern smartphone can do with ease.

That seems to be the case. Features like keyless entry are apparently run by that computer and so it never goes into a deep sleep state. Even then, 40W is pretty extreme. A typical high end mobile phone with wifi and 3G connections and background sync is more like 1 or 2W maximum (averaged over a day, of course).

Hopefully Tesla will explain it. They are usually happy to provide technical information.

Re:And, Folks, stay tuned.. (1)

Grishnakh (216268) | about 4 months ago | (#45622021)

That seems to be the case. Features like keyless entry are apparently run by that computer and so it never goes into a deep sleep state. Even then, 40W is pretty extreme. A typical high end mobile phone with wifi and 3G connections and background sync is more like 1 or 2W maximum (averaged over a day, of course).

Yes, but a mobile phone can't drive dual large displays with Nvidia GPUs; that system is surely comparable to a typical x86-64 desktop system, and one of those would easily use 40W at idle with the displays off. x86-64 CPUs are not low-power like ARMs.

It sounds like the problem is they didn't design this system for power management very well; they should have had some sort of multi-CPU system running both a low-power ARM and a high-power x86-64, so it could keep the ARM running while "off" to manage functions like WiFi/3G, background sync, and keyless entry, and only powering up the big CPU when the car (and its main displays) is "on". Of course, this would be somewhat complex, and require some fancy software architecture since ARMs aren't binary-compatible with x86-64s.

Re:And, Folks, stay tuned.. (4, Informative)

AmiMoJo (196126) | about 4 months ago | (#45622127)

Yes, but a mobile phone can't drive dual large displays with Nvidia GPUs

My phone drives a full HD (1920x1080) screen with desktop class graphics, more than enough for what Tesla does. They should be able to power down their GPU and screen when not in use.

Re:And, Folks, stay tuned.. (0)

Anonymous Coward | about 4 months ago | (#45622209)

My Linux laptop with a dual-core i5 processor, 4GB RAM, and SSD can idle with display and wifi active at around 11W or with display off at under 7W. This is idle with ability to ssh in and do stuff, not suspended in any way. A figure like 40W at idle sounds more like my desktop core i7 with multiple hard-drives and 24GB of RAM.

There is something wrong with their on-board computer if it cannot match the power profile of a regular x86-64 laptop computer with gigabytes of RAM, wifi networking, large SSD, and general desktop software. At the very least they could have sourced the same kind of motherboards and deployed them with an appropriate cooling solution for the car environment. No need for a hybrid with ARM processors unless they want to get down to mobile-phone levels of power draw.

Re:And, Folks, stay tuned.. (2)

jandrese (485) | about 4 months ago | (#45621771)

I imagine leakage from the batteries might be a good chunk of that. Even a small 0.5%/day leakage adds up when you've got a huge battery pack. 40W to run a dash computer (with the screen off!) is definitely excessive, especially since it uses a chipset designed for tablets and phones.

Re:And, Folks, stay tuned.. (1)

Grishnakh (216268) | about 4 months ago | (#45622029)

since it uses a chipset designed for tablets and phones.

It does? I thought it'd be comparable to a x86-64 desktop, and I thought I read it used dual Nvidia GPUs even. I could be wrong though.

Re:And, Folks, stay tuned.. (1)

Lazere (2809091) | about 4 months ago | (#45622293)

It does, but it uses the Tegra line which is Nvidia's mobile solution. So, it'd be an ARM chip in there, not x86.

Re:And, Folks, stay tuned.. (1)

CaptainLard (1902452) | about 4 months ago | (#45622363)

Obviously it's the DVR thats causing the power draw since we all know they draw 40W when turned off. Gotta keep those hard drives spinning through the night! Seriously Motorola/Comcast/Verizon, if you find it in your heart to shut them down 8 hours a day _for reals_ America would save like 10GWh a day! (40W x 8H x ~30M homes)

Re:And, Folks, stay tuned.. (0)

Anonymous Coward | about 4 months ago | (#45621373)

Thats (sorreee..) completely disingenous, 1100w (per day) is the actual current draw of an unused Tesla. My original point was maybe better stated as, "What is the actual current discharge rate of the batteries, is this also 1100w per day?" - just in case I wanted to do something strange like park on a street for more than 24hrs, or similar..

Re:And, Folks, stay tuned.. (2, Informative)

Anonymous Coward | about 4 months ago | (#45621225)

"1100w (per day)" ... whatever that means, it is wrong.

1.1 kWh = 45 watts for a day

Re:And, Folks, stay tuned.. (1)

tompaulco (629533) | about 4 months ago | (#45621705)

I agree. Any regular car would be pulling about 1/100th of that amount.
I imagine in an electric car quite a lot of energy is wasted in presenting the user with how much energy they are saving.

Re:And, Folks, stay tuned.. (-1)

Anonymous Coward | about 4 months ago | (#45621649)

Fuck you, I voted for this story in the firehose. If you don't like it, vote it down in the firehose. If you vote against it and it's posted anyway, well, who held a gun to your head and forced you to click the link?

Re:And, Folks, stay tuned.. (1)

fredprado (2569351) | about 4 months ago | (#45622331)

To be fair there were so many articles here about the problem being the end of the world that even if it is an advertisement this article still has a place here.

The Republican attacks... (-1)

Anonymous Coward | about 4 months ago | (#45621083)

will still continue. Their kind is not logical.

Re:The Republican attacks... (-1)

Anonymous Coward | about 4 months ago | (#45621233)

Makes sense when you consider that by and large republicans are more heavily invested in power derived from oil products. They are fighting the electric car/ solar/ windpower as these technologies are seen by them as 'the enemy' to their profits/ powerbase.

In Other News (4, Funny)

TechyImmigrant (175943) | about 4 months ago | (#45621115)

The 12V battery of a family member's Honda Civic didn't just draw more current than intended. It failed completely! The car could not start! The whole battery had to be replaced at cost to the owner and the Honda CEO was nowhere to be seen.

drain (3, Insightful)

themushroom (197365) | about 4 months ago | (#45621151)

The whole battery had to be replaced at cost to the owner and the Honda CEO was nowhere to be seen.

This would be because people will buy a Honda regardless of whether the dealer or company or CEO is a prick or not, where Tesla is trying to get itself a foothold in the market and Elon feels personally responsible if there's a defective product because it reflects badly upon the company. A hundred million Hondas Thousands of Teslas.

Re:drain (1)

K. S. Kyosuke (729550) | about 4 months ago | (#45621245)

Elon feels personally responsible if there's a defective product because it reflects badly upon the company

Are we sure his name is Elon, and not, for example, Uncle Enzo? ;-)

Re:drain (1)

DerekLyons (302214) | about 4 months ago | (#45621539)

Tesla is trying to get itself a foothold in the market and Elon feels personally responsible if there's a defective product that has reached the attention of the media because it reflects badly upon the company.

There, FTFY.
 
Elon Musk is a master at manipulating the media and the fanbois.

Please explain the Elon Musk hate (4, Insightful)

quadrox (1174915) | about 4 months ago | (#45622317)

In every piece concerning Tesla on slashdot, there are a few people making negative comments about Elon Musk. However, not once have I seen the complaints backed up with facts, examples, or otherwise, just negativity without any indication as to why.

Could someone please explaint to me why there is this hate on Elon Musk, and what it is about?

Re:In Other News (0)

Anonymous Coward | about 4 months ago | (#45621219)

Still though...replacing the 12V battery on a 18 month old vehicle doesn't make sense especially given the application (non-starting) of that 12V battery.

Re:In Other News (0)

Anonymous Coward | about 4 months ago | (#45621643)

I had to replace a lead-acid battery less than one year old which was used extremely infrequently for starting because it wouldn't hold a charge anymore. (I noticed one cell was swolen, also.) I assumed, and my battery store did not disagree with my assessment, that this was due to a manufacturing defect.

Re:In Other News (0)

Anonymous Coward | about 4 months ago | (#45621895)

Would be interesting to understand if this is an isolated case for Tesla. If it is, clearly the battery had a defect. Which is not a knock on Tesla, and probably not even a knock on their supplier assuming it's an outlying case.

That's shocking! (2, Insightful)

gweilo8888 (921799) | about 4 months ago | (#45621701)

My god, one person's battery failed completely? That's truly shocking! I've never heard of a battery failing before.

That is clearly a worse problem than every single Tesla Model S ever made sucking down 4.5KWh per day, every day, for months on end while Tesla sit on their fingers and do nothing to fix a problem that can apparently be fixed within hours of a single Tweet to the CEO.

And the fact that the "fixed" Tesla still sucks up enough power to drain the battery in any other car overnight, every night, for the rest of recorded time -- well, that's just the price of having a shiny car with no doorhandles or keys, right? Pretty trumps energy efficient and intelligently designed every time!

Re:That's shocking! (1)

gweilo8888 (921799) | about 4 months ago | (#45621863)

That whooshing sound was me missing the joke. Although I can perhaps be forgiven, bearing in mind the levels of rabid Tesla fanboyism around these parts.

Re:That's shocking! (4, Interesting)

Idarubicin (579475) | about 4 months ago | (#45621941)

And the fact that the "fixed" Tesla still sucks up enough power to drain the battery in any other car overnight, every night...

I'm kind of wondering if "sucks up" is really the right verb to be using here. I mean, the article's author notes that the battery pack has a nominal 85 kWh capacity. Losing 1.1 kWh in 24 hours (note, not just "overnight") from a fully-charged battery pack is a shade less than 1.3% of the total capacity per day; if it maintained that rate of discharge, it would drain the battery pack in about 2.5 months.

The question I have, then, is how much of that consumption is replenishment of unavoidable self-discharge from the batteries, versus actual electricity used to power the various onboard electronics packages. That is, even if you physically cut every connection between the car and the battery pack in the evening, how much would the charge need to be topped up come morning?

$80k car, $10 cutoff switch? (1)

bob_super (3391281) | about 4 months ago | (#45621131)

Can't they put a big red cutoff switch for the battery, for owners who won't be charging to just physically disconnect the battery when they're parked?

If I had one, I wouldn't need the computer/GPS/3G_app/dataminer to keep running when I'm grocery shopping or working, as long as it reboots in less than, say, a minute.

Do that are you're down to the raw battery leakage only.

rechargable battery decay (2)

themushroom (197365) | about 4 months ago | (#45621221)

Batteries discharge when doing nothing. What if the 1.1kWh is the normal for just sitting there like if it wasn't even in the car, plus some trickle for things like the clock and other persistant items? This might say more about the batteries' charge decay rate than the rest of the system causing a drain (though I do figure, fairly, there's a little more than just the clock and expected no-load decay at issue here).

Re:rechargable battery decay (1)

bob_super (3391281) | about 4 months ago | (#45621387)

What you call decay is what I call "raw battery leakage". You're more correct.

Unless you're afraid your car will be stolen, there is no reason for anything to be powered when you're not using or charging it.

Throw in three more cells if that's what it takes to power the door locks, and let me physically unplug everything else.

Re:rechargable battery decay (1)

Entropius (188861) | about 4 months ago | (#45621973)

The radio receiver for the keyless entry door locks ought to be able to idle on microwatts, and wake up and use milliwatts when it needs to spin up the computer that determines whether a received signal is actually the right key to open the locks.

Re:$80k car, $10 cutoff switch? (3, Informative)

silas_moeckel (234313) | about 4 months ago | (#45621259)

You do realize the thing does not have a key. Hell you can not even open the doors without the fob they are literally retracted into the car.

Re:$80k car, $10 cutoff switch? (1)

140Mandak262Jamuna (970587) | about 4 months ago | (#45621695)

The first car I owned was a 1986 Nissan Pulsar. Those days retractable headlights were much in vogue. Toyota Celica, Mazda Miata and some of these Nissans had them. There was a switch to disable the retraction and leave it permanently up. I used that to leave it up all the time based on a simple logic. "This car is old, and this damned retraction thingie is going to fail someday. When it does, I want it fail with the lights up not lights down". My logic was impeccable and all the PIGS (poor indian grad students) left their headlights up if they had retractable head lights.

I wonder if Tesla has a switch to leave its door handles out.

Re:$80k car, $10 cutoff switch? (2)

CanHasDIY (1672858) | about 4 months ago | (#45621849)

The first car I owned was a 1986 Nissan Pulsar. Those days retractable headlights were much in vogue. Toyota Celica, Mazda Miata and some of these Nissans had them. There was a switch to disable the retraction and leave it permanently up. I used that to leave it up all the time based on a simple logic. "This car is old, and this damned retraction thingie is going to fail someday. When it does, I want it fail with the lights up not lights down".

I'm certain this is absolutely pointless to say now, but most of those setups were designed so that spring pressure had to be overcome to close the lenses; that way, if the mechanism did fail, it *should* fail-safe to the open position.

I wonder if Tesla has a switch to leave its door handles out.

If I owned a Tesla with a dead 12v battery right now, I'd be afraid to know the answer.

Re:$80k car, $10 cutoff switch? (1)

TechyImmigrant (175943) | about 4 months ago | (#45622149)

>*should* fail-safe to the open position.

Not in my first MX5. It failed down.

My second MX5 and my first 350Z both solved this problem by not having retractable lights.

Re:$80k car, $10 cutoff switch? (1)

fahrbot-bot (874524) | about 4 months ago | (#45622189)

I'm certain this is absolutely pointless to say now, but most of those setups were designed so that spring pressure had to be overcome to close the lenses; that way, if the mechanism did fail, it *should* fail-safe to the open position.

My 1987 Honda Prelude had retractable headlights - technically rotating. They used a screw mechanism to raise/open lower/close - no springs. The car also had a button to manually raise the lights w/o turning them on - I used that for cleaning and to raise them in case of snow/ice conditions, so they weren't frozen closed.

Re:$80k car, $10 cutoff switch? (1)

0123456 (636235) | about 4 months ago | (#45622217)

I'm certain this is absolutely pointless to say now, but most of those setups were designed so that spring pressure had to be overcome to close the lenses; that way, if the mechanism did fail, it *should* fail-safe to the open position.

Ha-ha. Americans and their electronic complexity.

My Italian car with flip-up headlights just had a knob you turned to raise them if the motor failed.

Re:$80k car, $10 cutoff switch? (0)

silas_moeckel (234313) | about 4 months ago | (#45621901)

It is an 80k car I doubt many owners will ever change a tire forget worrying about the door handles, lets remember EV's are disposable there battery s degrade and they are worth nothing, your not going to see many go much past 10 years.

Re:$80k car, $10 cutoff switch? (0)

Anonymous Coward | about 4 months ago | (#45621269)

And what? Have a faggoty mechanical switch to turn the car back on? Have to reset the clock? Fuck that.

Re:$80k car, $10 cutoff switch? (1)

bob_super (3391281) | about 4 months ago | (#45621357)

Yes. Your app-enabled, GPS-equipped, 17-inch-touchscreen-dashboard car needs you to know what time it is, dear troll.

Re:$80k car, $10 cutoff switch? (4, Interesting)

Ralph Wiggam (22354) | about 4 months ago | (#45621471)

One of my favorite features of my Nissan Leaf is that I can turn the air conditioning or heater on from a phone app. I can also check the state of the batteries and the time remaining until it fully charges. So even in standby, electric cars are doing a decent amount of stuff.

Re:$80k car, $10 cutoff switch? (1)

bob_super (3391281) | about 4 months ago | (#45621565)

My question is "how much of that stuff is actually necessary and worth draining the battery for?"

I know about AC in Texas or heaters in International Falls. Even if that's half the year, what about cutting off the waste the rest of the year?
After the first month, you know exactly how long it takes to charge and how low batteries are after 51 miles. And if you don't yet, how often does it matter, when you're away from the car?

Re:$80k car, $10 cutoff switch? (1)

mrchaotica (681592) | about 4 months ago | (#45621877)

After the first month, you know exactly how long it takes to charge and how low batteries are after 51 miles.

Not necessarily. It depends not only on your driving pattern but also the ambient temperature (which obviously varies according to season unless maybe you live in the tropics).

Re:$80k car, $10 cutoff switch? (1)

Albanach (527650) | about 4 months ago | (#45621731)

My raspberry pi or my cellphone both have easily enough CPU to run a basic web interface and opeate a couple of switches, yet neither draws anything like 40 watts.

Re:$80k car, $10 cutoff switch? (1)

hawguy (1600213) | about 4 months ago | (#45621727)

Can't they put a big red cutoff switch for the battery, for owners who won't be charging to just physically disconnect the battery when they're parked?

If I had one, I wouldn't need the computer/GPS/3G_app/dataminer to keep running when I'm grocery shopping or working, as long as it reboots in less than, say, a minute.

Do that are you're down to the raw battery leakage only.

You're willing to sit in your car for 60 seconds while you wait for the computer that runs it to boot? You're much more patient than I am.

Re:$80k car, $10 cutoff switch? (1)

0123456 (636235) | about 4 months ago | (#45622249)

You're willing to sit in your car for 60 seconds while you wait for the computer that runs it to boot? You're much more patient than I am.

My Civic takes about five seconds to 'boot' after I turn the key (i.e the point where the digital displays reach their normal driving status). That's about as long as my Windows PC takes to boot to the login screen after it exits the BIOS, so it's clearly not hard to do.

1.1 kWh is still too much (1, Insightful)

Anonymous Coward | about 4 months ago | (#45621145)

That's 45 watts continuously, it should be more like 10. Multiply the wasted energy times tens or hundreds of thousands of cars and all of sudden you're talking about the output of an energy plant wasted every day.

Not fixed yet (0)

Anonymous Coward | about 4 months ago | (#45621169)

1.1 kWh is a hell of a lot energy. Something is still seriously wrong if it's not lost in balancing the battery pack.

Re:Not fixed yet (0)

Anonymous Coward | about 4 months ago | (#45621213)

No, it isn't. It's about the heat put off by a 45 watt bulb.

Re:Not fixed yet (0)

Anonymous Coward | about 4 months ago | (#45621349)

It's still at least an order of magnitude too much power. I know, I design EV electronics.

Re:Not fixed yet (0)

Anonymous Coward | about 4 months ago | (#45621441)

Oh wise Anonymous armchair expert, how do you get 4.5W when the self-discharge on the traction pack is already about 10W?

Re:Not fixed yet (1)

Em Adespoton (792954) | about 4 months ago | (#45621689)

Oh wise Anonymous pundit, you get it by looking at the 12v battery which is doing the leeching -- the traction pack runs off the main battery, unless I'm mistaken.

When the vehicle is off, the 12v battery should be powering something about equivalent to a smartphone, so 4.5v sounds about correct. Amperage should be minimal until some mechanical process is kicked off, like unlocking the doors, turning on A/C, powering up the antenna(s) etc.

What this really feels like to me is that some secondary process controlled by the computer that's backed by the 12v battery isn't going into standby correctly -- likely culprit would be the wireless communication radio transmitter (not sure what type this car uses, so leaving vague).

One thing for owners experiencing this leakage to do would be to try parking their S in the garage overnight one night, and then outside the next night, and see if the consumption is visibly different. If it isn't, there's a design flaw to be tracked down. Has this system been EnergyStar rated?

Customer care (0)

Anonymous Coward | about 4 months ago | (#45621171)

Some pretty fantastic customer care tbh

Not a massive difference (0)

Anonymous Coward | about 4 months ago | (#45621181)

That's still 46W permanently, isn't it? More than most devices. Is that really what's needed to keep the batteries charged?

just hang in there, help is on the way (0)

Anonymous Coward | about 4 months ago | (#45621291)

I'm sure Tussle owners can manage the expense for awhile, eh?

4.5 kWh per day (0)

Anonymous Coward | about 4 months ago | (#45621295)

Huh? 4.5 kilo watts per hour per day?

Re:4.5 kWh per day (3, Informative)

Trepidity (597) | about 4 months ago | (#45621367)

That's 4.5 kilowatt-hours per day. I.e. in a day, it draws 4.5 kWh of energy.

A watt is a unit of power. A watt-hour is a unit of energy. 1 Wh = 1 W x 1 h. Similarly, 1 kWh = 1 kW x 1h. A 200-watt motor left on for an hour will draw 200 Wh of energy. A 200-watt motor left on all thetime will draw 200 W x 24 h = 4.8 kWh of energy per day.

hire Andrea Rossi (2)

Thud457 (234763) | about 4 months ago | (#45621411)

For a $100,000 car sold by some Ian Flemming villain, I expect the damn thing to be giving back more than 1.1 KW just sitting in my driveway. And v2.0 better be able to hover.

My Question (1)

CanHasDIY (1672858) | about 4 months ago | (#45621353)

How much electricity does a fossil-fuel vehicle use in a day while sitting, turned off?

If it's anywhere near 1.1 kWh, then yea, no big deal for the Tesla to have a similar draw.

Re:My Question (0)

Anonymous Coward | about 4 months ago | (#45621479)

How much gas can I put in my tank by plugging it in on my wall socket overnight at home when I'm low on gas?

If it's anywhere close to being a full tank, then yea, no big deal for the regular car to have a similar running cost.

Re: My Question (1)

chaboud (231590) | about 4 months ago | (#45621487)

It is nowhere near that in a normal car...

I have a 40Ah battery in my car (at 12V, that's 480 Wh). If it were drawing like a Model S, it would be dead in under half a day... I often go *weeks* without driving.

  45W is huge. Your phone in active standby (screen off) is probably around 45mW... A Macbook Air under load is 45W. That is an *astronomical* amount of energy in standby. Even the cellular connection can only account for, maybe, 1W. Is this for the auto door pulls? Battery heaters?

Isn't the model number the kWh of the battery pack? The 85 is an 85kWh car, right?

So, you know, when you go on vacation, make sure to leave your car plugged in...

Re: My Question (1)

tlhIngan (30335) | about 4 months ago | (#45622003)

I have a 40Ah battery in my car (at 12V, that's 480 Wh). If it were drawing like a Model S, it would be dead in under half a day... I often go *weeks* without driving.

    45W is huge. Your phone in active standby (screen off) is probably around 45mW... A Macbook Air under load is 45W. That is an *astronomical* amount of energy in standby. Even the cellular connection can only account for, maybe, 1W. Is this for the auto door pulls? Battery heaters?

Isn't the model number the kWh of the battery pack? The 85 is an 85kWh car, right?

So, you know, when you go on vacation, make sure to leave your car plugged in...

Well, the high voltage battery constantly charges the 12V battery, and the 12V battery enables the contactors for the high voltage battery (as a safety feature). If you remove the 12V battery, the high voltage battery disconnects automatically (if you're needing to rescue someone inside, the rescuer manual says to cut the 12V battery cables to disconnect the high-voltage battery).

I suppose part of it could be to power the big relays that connect the battery to the rest of the high voltage lines. (remember, those things have to pass a huge amount of current, so the 12V coil may have to be fairly beefy).

It's also just a relay - unlatched. Remove the battery and the HV disconnects. Reconnect it and the HV reconnects.

Re:My Question (0)

Anonymous Coward | about 4 months ago | (#45621495)

A typical 12 V automotive battery might have a capacity of 100 Ah. That corresponds to 1200 Wh, or 1.2 kWh. The Tesla would drain that battery in about a day, whereas in a typical car, the battery would probably last at least a few months. So, based on that, the Tesla is using 50 to 100 times more power while sitting.

Re:My Question (0)

Anonymous Coward | about 4 months ago | (#45621515)

Considering how the 12V battery on a combustion car is ~100Ah, it's no where near 1.1kWh.

Standard Consumption (1)

Anonymous Coward | about 4 months ago | (#45621579)

A standard automobile uses minimal electricity. The need to maintain power to the clock, a trickle to maintain memory for the radio presets, and keep the keyless entry system listening for the activation code. These things take a tiny amount of electricity. Approximate usage when ignition is off is ~500mA . This equates to 0.144kWh per day!

  Tesla's "fixed' consumption of 1.1kWh per day is an outrageous 8 times higher in comparison. But, they are also keeping their computer up and running all the time in order to maintain cloud connection for monitoring, updates, remote access...

Re:My Question (1)

Chuckstar (799005) | about 4 months ago | (#45621757)

A car battery contains about 1 kWh of power. So this kind of draw would drain a car battery in on day. You could probably leave a car parked for a month-or-so without worrying about the battery, so figure the Tesla is using power about 30x faster than a normal car. That further implies a normal car is running at about 1.5 Watts (which sounds about right for a computer running in low-power mode and occasionally checking for things like a nearby key fob for keyless entry).

Of course, you'd expect to lose charge in a 60kWh lithium ion battery at a rate of about 5-10 Watts. Adding the 1.5 Watts that a car's computer can expect to use, and the Tesla should be using about 6.5-11.5 Watts when parked. I can't tell you where the other 33.5-38.5 Watts is going.

Aux battery (3, Informative)

Animats (122034) | about 4 months ago | (#45621393)

There's a 12-volt lead-acid battery in the thing to power the auxiliary systems. It's the same size as a regular automotive battery, but apparently is a sealed type, intended to last the life of the vehicle. Since it doesn't need to provide cranking power, a high-current battery isn't necessary.

Tesla owners have been reporting 12 volt battery failures for months. Usually the charging system reports "12 volt battery failure", but apparently a partial failure is possible, where the aux battery is an energy drain but still functional.

That's a lot of 12V loss (1)

johndoe42 (179131) | about 4 months ago | (#45621575)

Before the battery replacement, the car lost 3.5kWh/day. After the replacement, it lost 1.1kWh/day. That's a difference of 2.4kWh/day, which is 100W. That's something like 8 Amps internally leaking in the 12V battery. That seems shockingly high. Or maybe there's something else going on. If the battery was marginal, then perhaps the car's DC-DC converter was continually "charging" it but actually overcharging it. Then it would be electrolyzing 8A worth of water and battery acid. I expect that would make a giant mess. Alternatively, it just keeps running the DC-DC converter at very low output. The DC-DC converter could be incredibly inefficient when producing just a little bit of current (Tesla is reputed to use a huge (~200A) DC-DC converter, so the thing could be running at about 1% of rated output at, say, 10% efficiency).

Tesla owner's findings... (5, Informative)

SternisheFan (2529412) | about 4 months ago | (#45621617)

Found this article from November 25, 2013. Three excerpts below...

"According to Tesla, the car needs a constant flow of power to keep its computers and systems switched on 24/7, ready to boot up instantly when the driver gets into the car. (It's a popular myth among Model S owners that much of the vampire power goes to keep the battery warm during cold nights. This is simply not true.) According to Tesla, there is no thermal management of the Model S battery when the car is turned off and not charging--no matter how cold it gets."

"Ironically, the Model S had very little vampire drain when it was first introduced. My owner's manual is based on the original software in the car. "When you're not driving Model S, the Battery discharges very slowly to power the onboard electronics," it purrs reassuringly. "On average the battery discharges at a rate of 1 percent per day. Unfortunately, the "sleep mode" software in those early cars triggered all sorts of glitches in the car's other systems. Eventually, the problems became so persistent that Tesla simply disabled the sleep mode. With sleep taken away, the vampires came out to play. And instead of draining 1 percent every 24 hours, the Model S battery suddenly began losing 5 or 6 percent of its charge every day. (In the case of 60-kWh cars like mine, it's closer to 7 or 8 percent.)"

"So far I've run three overnight tests with the kWh meter. For each test, I charged the car up in the evening to its usual selected level (In my case, about 80 percent). Then I removed the charge plug. I allowed the car to sit unplugged overnight and on into the next day, until I needed to drive it. (Typically a span of 12 to 24 hours.) Before driving it, I plugged it back in to top off the vampire-depleted battery back to its original level. Then I checked the kWh-meter. Test results: The three tests showed vampire losses of 2.3 kWh in 17 hours, 1.9 kWh in 23 hours, and 4.2 kWh in 18 hours. Total vampire power lost was 8.4 kWh in 58 hours. That's an average of 3.5 kWh per day--roughly 25 percent lower than the losses I measured previously. I can't explain the wide variation in the vampire draw over the three tests. Clearly, more than three tests will be required to come up with an accurate figure. But it's clear to me that the new vampire-slayer software is pretty weak stuff. It's better than nothing, I suppose. A 25-percent improvement means that the 20,000 Model S cars now on the road will only waste about 70 megawatt-hours of power a day, down from 90 MWh. And it means that Musk's anti-vampire prediction has turned out to be one-quarter true in twice the time. Update 6.0, anyone?"

http://www.greencarreports.com/news/1088648_life-with-tesla-model-s-even-after-update-vampire-draw-remains [greencarreports.com]

Re:Tesla owner's findings... (1)

eudaemon (320983) | about 4 months ago | (#45621653)

I'm a fan of Elon and Tesla, but it sounds like they need to invest heavily in fixing sleep mode.

Re:Tesla owner's findings... (3, Informative)

SternisheFan (2529412) | about 4 months ago | (#45621711)

Doh! I should have fully RTFA completely through :( Turns out it was the car's defective 12volt battery

And so it looks like my vampire was indeed my car's defective 12-Volt battery

But does the 12-Volt hypothesis explain why so many Model S owners reported similar problems on the various owner forums? Do they all have bad 12-Volt batteries?

And what about the odd fact that most of the reported problems seem to be in 60-kWh cars? The Tesla spokesman told me that the 60- and 85-kWh batteries are identical, vampire-wise.

http://www.greencarreports.com/news/1088929_life-with-tesla-model-s-electric-draw-vampire-slain-at-last/page-2

Re:Tesla owner's findings... (1)

Hatta (162192) | about 4 months ago | (#45621903)

"According to Tesla, the car needs a constant flow of power to keep its computers and systems switched on 24/7, ready to boot up instantly when the driver gets into the car.

That's just stupid. It won't hurt anyone to wait 20 seconds for the computers to boot up. If it takes longer than 20 seconds to boot the cars computers, WTF? PCs only take minutes to boot because of legacy BIOS and OS writers who don't care about boot times. Embedded computers suffer none of these problems.

Overnight? What about a week? (0)

Anonymous Coward | about 4 months ago | (#45621775)

Say you take this to the airport and go away for a week or two? Will there be any juice left to run the car? I think most people need a car that doesn't need so much pampering every night.

Re:Overnight? What about a week? (0)

Anonymous Coward | about 4 months ago | (#45621931)

Say you take this to the airport and go away for a week or two? Will there be any juice left to run the car?

Nope.

Elon Musk owes an apology to John Broder (1)

Mike Buddha (10734) | about 4 months ago | (#45621783)

The problem with the 12 volt battery is exactly what caused all the problems with the review car that John Broder wrote about. Hmm, I guess Broder might not have been the big liar that Musk and his gang of fanboys painted him out to be.

Wow, this guy is a complete nut job. . . (0)

Anonymous Coward | about 4 months ago | (#45621797)

This [teslamotors.com] is how other Tesla owners responded to what we now know was a legitimate complaint. I ask you, who are the real nut jobs?

Little discrepancy in the summary (1)

jones_supa (887896) | about 4 months ago | (#45621987)

Then a few hours later, he tweeted that the issue had to do with a bad 12-volt battery. Turns out Tesla had already called the owner of the affected car and sent a service tech to his house to replace that battery — and also install a newer build of the car's software.

So, it seems to be solved, but Tesla may either need to fix some software, or start sending a few new 12-volt batteries out to the folks still experiencing the issue.

Well, just to be accurate here. As far as we know, the problem was tracked to be a bad battery. Thus it does not make sense to suggest that they "may need to some software". During servicing, the faulty car's software was possibly just upgraded "while we are at it", without the upgrade necessarily having to do anything with the battery.

Re:Little discrepancy in the summary (0)

Anonymous Coward | about 4 months ago | (#45622031)

Good catch. You're correct. :)

Unless, of course, the software somehow breaks the battery, but we haven't heard about something like that so far.

In every Tesla thread I mean to ask... (3, Interesting)

Anonymous Coward | about 4 months ago | (#45622019)

What is the US energy mix? Is a Tesla better for the environment than a small petrol driven car? What about the embodied energy of a Tesla vs. a conventional car?

I know here in Australia where we burn brown bloody coal an electric car produces more emissions than a V6.

Re:In every Tesla thread I mean to ask... (0)

Anonymous Coward | about 4 months ago | (#45622139)

What is the US energy mix?

That would be far too aggregate a figure to be useful. The US is a big place with a lot of distinct climate/geography mixes. For example, the Midwest uses mostly coal and/or natural gas, but in the Pacific Northwest wind power makes up a significant chunk.

Volvo 240-DL Battery Dies Due to Dashboard Clock (1)

stoicio (710327) | about 4 months ago | (#45622111)

Sad but true.
I contacted Volvo but they didn't send a repair person out.

I can't believe it. I trusted Sweden and this is how I am repaid....
Damn you Sweden!!!!

I just replaced it with a, standard domestic brand, Ford Pinto.
Sounded like a great deal. We'll see how it goes.
Frick'n Sweden.....

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