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Alarming amounts of cold weather vampire drain

Discussion in 'Model 3' started by voip-ninja, Feb 12, 2019 at 7:13 AM.

  1. voip-ninja

    voip-ninja Give me some sugar baby

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    TPMS;

    Model 3 TPMS sensors are junk

    Cabin heating.... I've gotten in my car after pre-heating the cabin to 75F and a portable digital thermometer shows it's really about 68F. To add to that the automatic climate control will have barely any air volume coming out of the vents so my hands are cold the entire time I'm driving. To counter this I need to crank the temp up to 80F and crank the fan speed up to get anything to happen approaching the cabin warming capability of any of my other cars including the eight year old Honda Fit I purchased last year for $7,000.
     
  2. voip-ninja

    voip-ninja Give me some sugar baby

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    Plugging in doesn't change the equation on energy used. It just shifts the cost of keeping the car comfortable to my wallet instead of my employers.
     
  3. Big Earl

    Big Earl Supporting Member

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    The snowflake icon and the blue "unavailable" range are accounted for in the state of charge display. In other words, if you parked with 50% and 5% of your battery is showing blue in the morning, your range display would show 45%. If you lost 2% of your battery due to vampire loss overnight and you had 5% showing blue, your state of charge would show 43%.
     
    • Informative x 1
  4. voip-ninja

    voip-ninja Give me some sugar baby

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    This is helpful. I still ended up with 10% range loss from the time I parked the car yesterday afternoon till the time I got to work 10 miles away this morning when the snowflake icon was gone.

    To add some bonus misery, the TPMS warnings went off while I was driving home yesterday afternoon in 30F temps. The car was complaining that 3 of the 4 tires were at the incredibly low tire pressure of 41 PSI... heavens to Betsy! I put my gauge on them and they all measured at 44 PSI.
     
  5. happyzod

    happyzod Member

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    This isn't vampire loss. It is the car heating up the battery so it doesn't get too cold. Does BMW know how to make good cars? Not sure after the whole spontaneous combustion fires all over the place.
     
    • Disagree x 1
  6. voip-ninja

    voip-ninja Give me some sugar baby

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    #26 voip-ninja, Feb 12, 2019 at 9:15 AM
    Last edited: Feb 12, 2019 at 9:49 AM
    //SNARK_MODE_ON

    I have owned many BMWs. They have their problems but none of mine have ever caught fire. Nothing on any of my BMWs have really been annoying enough that I have felt the need to call them out on it.

    I like my Tesla, it drives very well and is in its own segment with no competition which is why I own it.

    I want to love it but I can't because of the many problems. When any of my BMW or Mini vehicles have needed service I make an appointment with an extremely professional service adviser. I then bring my car in on the appointed day and immediately pull out in a shiny new loaner vehicle. They call me to status me throughout the day on what is going on and then I bring the loaner in, typically the same day, and pick my car up and it's fixed.

    With Tesla I try to make an appointment to get things looked at and I reach a national service center where I am forced to deal with call center employees who know far less about the car than I do. I make an appointment. I bring the car in and drop it off and deal with a bunch of stressed out people that are handling more work than they know what to do with. 100% of the time that I bring the car in I am told that they will need the car to sit on their lot where it could be damaged for 4-6 days before a technician can even look at the car,.this information is never available from the call center when booking the appointment.

    The smaller the problem with the car the longer this wait will be. I am told that I can only get the item I scheduled fixed while they have it, that if there is anything else that needs to be done with it I need to make another appointment and bring it back in another time for those items where the car can again sit for days while I drive around in an ancient loaner.

    If there's any push back about the lengthy time to get the car serviced I am given lip-service that saving the world is hard, and that in addition to writing a check for >$60,000 for a brand new car with lots of annoying problems I should be thankful that Elon tweeted that he's going to make service a priority and that things will get better someday.

    I am given a scratched up 6-7 year old loaner car to drive and service warns me that I will be billed if there's any damage to their scratch & dent special when I bring the car back a week or two later.

    Nobody calls me or tells me anything about what is going on with my car as it languishes for days waiting for a repair. Suddenly I get a call that my car is done. They can't tell me exactly what they fixed. I go to pick the car up and a smirking millennial comments that it's funny that the ticket says that a "foreign factory object was found in the passenger footwell ducting... that's funny, what does that mean"? I inform the young imbecile that it means that when they built the car they somehow dropped something inside of the car's climate system or open part of the unibody and it's been rolling around and squeaking in there since the car came off the line. The person looks confused and goes back to smirking at their SnapChat feed.

    //SNARK_MODE_OFF

    About the only good thing I can say about Tesla service is that mobile service is pretty good but the things they can fix are pretty small and if it will take more than a bit of time to look at something they try to push it off to the local service center.
     
    • Informative x 1
  7. Garlan Garner

    Garlan Garner Well-Known Member

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    How much do you think it should have lost over 12 hours? 1% - 2% - 3%? certainly not 4% or 5%....right?

    Or how about "nothing"?

    What would be an acceptable number?
     
  8. MorrisonHiker

    MorrisonHiker S 100D 2018.50.6

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    We heard this and tested it in the snow last Wednesday. In our tests, the FLIR didn't show the cameras were heated while the car was just sitting outside in the snow.

    I didn't have to replace the brake pads on my old CR-V until I had over 180,000 miles and it didn't have any regen...just a lot of highway miles! ;)
     
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  9. Garlan Garner

    Garlan Garner Well-Known Member

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    You need an electric car tire gauge? Your ICE car tire gauge is useless.

    lol.
     
    • Funny x 1
  10. voip-ninja

    voip-ninja Give me some sugar baby

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    I think that if it needs to consume more power in cold weather when it's just parked that Tesla should be more transparent about this when they advise what typical loss is for purposes of leaving the car parked for awhile, etc.

    Tesla is borderline aggressive with publishing the amazing savings you will get with a Tesla 3 vs. the ICE competition. Certainly a Tesla should be cheaper to operate at least during the warranty period but Tesla should not advertise electric usage X when it turns out my car consumes about 40% more than that starting in November.
     
  11. derotam

    derotam Member

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    Not saying that the TPMS might not also be off but...when was the last time you sent your gauge out for calibration? :)
     
  12. AlanSubie4Life

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    #32 AlanSubie4Life, Feb 12, 2019 at 10:56 AM
    Last edited: Feb 12, 2019 at 11:19 AM
    As others have indicated, the snowflake makes things difficult to determine, exactly, for a single overnight period. I think the best way to determine approximately how much vampire drain you have is to look at your wall-to-wheels efficiency for the period, assuming you have a way to meter that (either at home or using a Chargepoint or Supercharger). It's really all that matters, as you say. It won't be as precise, but probably the only way to determine about how many % you really lost due to vampire. You still have to make some assumptions about charger/battery charging heating efficiency (seems to be 87-90% if you're not using a Supercharger - so potentially that slop might create large error on your vampire drain number), so it won't be precise, but in cold weather conditions I think it is really difficult to come up with a clear number unless you look at your efficiency for a full cycle. Obviously also includes heating losses, etc., but you can monitor that on the in-car display assuming you don't do any significant heating of the vehicle while it's parked (the in-car display does not count any energy you use while you are parked).

    Some of the apps track the miles/energy added but you have to be careful to distinguish between miles/kWh added to the pack and kWh drawn from the wall. (Which are different by about 10-13%.)

    Assuming you charge to the same %/miles as the prior charge, and you're not using a supercharger:

    Total kWh added (measured at the wall) = (Miles Since Last Charge * kWh/mi since Last charge + Parked Heating & Other losses (not quantifiable) + Vampire losses (in kWh) )/0.87

    Again the 0.87 is approximate and is closer to 1.0 (I don't know what it is, it is less than 1.0) for a Supercharger. But you can solve this formula for Vampire losses to get a rough idea. Obviously if you have non-quantified losses then you can't solve it.

    Personally, I have seen an instance about 10 days ago on version 50.6 where I inexplicably lost 10-14 miles in a very short period of time, but then soon thereafter, I came back to the car after leaving it overnight unplugged and it had 7 miles MORE than when I left it (this is the only time I have ever seen the miles go up). And this was NOT in cold conditions or with a snowflake. So, the "roundtrip" monitoring is really the only way to go.

    Monitoring the true energy content of a battery accurately is really, really hard to do over a huge range of temperatures & SoC. That's one of the ways to explain this bizarre behavior of the rated miles display (in addition to just simple software bugs).

    I would expect 4 miles per day of vampire drain (assuming about 1 hour of driving per day). That's what I have seen quite consistently over a long period of time. It's been briefly worse when I've left a door or trunk open or whatever, and generally seems slightly worse than that (5 miles per day?) on version 50.6.

    Lifetime, I would estimate about 10-15% of my energy usage is vampire drain. I get about 30kWh/100miles (300Wh/mi batt-to-wheels) when driving the P3D+, and my wall-to-wheel energy use is closer to 38kWh/100miles, lifetime.

    I've found that the parking sensors are sometimes on and sometimes off with my FLIR. I haven't gone back to experiment to try to determine the pattern - but I wonder whether it depends on whether it is light or dark. And I've never seen the cameras heated in the FLIR. But I'm not in a location where they would need to be heated.
     
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  13. voip-ninja

    voip-ninja Give me some sugar baby

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    I own five pressure gauges and they all agree to one another within 1-2 PSI. The issue is that Tesla does not account for altitude changes when they read tire pressures and will erroneously complain when the pressures are low and they are in fact within spec.

    Even worse problem for Tesla is that the car will alarm when it thinks the tires are 2-3 PSI below the recommended level that is on the door sticker. That is simply absurd.
     
  14. diamond.g

    diamond.g Active Member

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    Did the car app report 75 interior temp? I seem to recall folks somewhere saying that the interior sensor sin't that accurate. Or maybe that was the exterior.
     
  15. StellarRat

    StellarRat Member

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    Well, the effective tire pressure does in fact change with altitude. Are they reading higher pressure at high altitude and lower pressure at low altitude?
     
  16. voip-ninja

    voip-ninja Give me some sugar baby

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    I don't recall a single day where I saw 1% nightly battery drain starting in about October when temps cooled off. Perhaps the 1% really applies to warmer places like San Diego or Miami.

    I agree that the only way to definitively prove how much drain there is can only be done by charging the car to the same level every day over a period of time and comparing to miles driven, foregoing use of cabin pre-heating and so forth.

    Since I charge for work at free and can't charge to the same level every day (I have to unplug after four hours to avoid being charged) I'm not the right guy for that task.

    My beef is more with what I view as border-line deceptive information that Tesla is providing on the estimated savings and kwh usage of their cars compared to what myself and many other owners have seen in the real world.
     
  17. voip-ninja

    voip-ninja Give me some sugar baby

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    The exterior sensor is always off by about 5F.

    Interior wise the climate control was set to 75F and the vents were barely running, if there's a way to display what the car thinks the internal temp is I'm not familiar with it. When the car was doing this my separate thermometer was showing 68F when sitting on the center arm rest.
     
  18. voip-ninja

    voip-ninja Give me some sugar baby

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    They apparently always treat the pressure as if the car is at sea level and don't do any adjustment for altitude. Every other car I have that has TPMS has sensors that agree with what a handheld gauge show, to within 1-2 PSI. Apparently this is a super technical challenge that is above Tesla's ability to fix... even though the car has a GPS and always pretty much knows what altitude it is at.

    Or potentially they don't care because I guess that whiny high altitude people are not much of a priority compared to putting fart sounds in the cars.
     
    • Funny x 1
  19. AlanSubie4Life

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    It's possible that it is higher in colder climates (I see more like 1.3%/day). I have no way to really know. Anecdotally, my brother in chilly but not extremely cold Seattle left his car for 2 weeks and saw about 4-5 miles a day after correcting for the snowflake. Due to SoC estimation difficulties, and real (but temporary) available energy drop due to temperature change, I think you shouldn't read too much into your rated miles after a drive when the battery is warm, compared to what you see in the morning when the battery is quite cold. It's likely to be a bit pessimistic.

    I understand it's not really something you can get a handle on, and it's really not worth your time to measure it. As a rule of thumb, budget a minimum of 4 miles/day (multiplied by 1.13*242Wh/mi if you want to refer it approximately to your kWh from the wall). It definitely won't be less than that (I've never seen any verified long-term report of substantially less).

    I completely understand your frustration. I think everyone should expect higher usage in the winter due to heating use and that is not a source of frustration for me; my frustration is actually more with the "best case" energy usage of the vehicle. I'm also not frustrated at all with my 300Wh/mi use; that's what I expected with the PS4S tires. My problem is that the best case, most highly optimized, wall-to-wheel consumption, is much higher than Tesla & the EPA indicate, even when a user is getting 240Wh/mi (or 220Wh/mi or whatever) while driving, and there's really no way to argue otherwise (unless you drive all the time (20,000-30,000+ miles a year), and then you'll do quite well).
     
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  20. apsen

    apsen Member

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    I'm aware of only one way to see the interior temperature - in the app.
     
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