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Suddenly higher power consumption - ideas?

Discussion in 'Model S: Battery & Charging' started by PeterK, Oct 29, 2013.

  1. PeterK

    PeterK Model S Owner

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    I've had my S85 vin 60xx since March, averaging 358 Wh/mi over 9394 happy miles. Two weeks ago I had the car in to address the steering click and a few minor issues. They also rotated my stock 19" tires. I'm on v4.5 (1.33.61).

    In the past week or so - perhaps since the service - my Wh/mi is up dramatically. I generally keep the Trips meter up on the dash, and reset trip A before longer drives as well as watch the Since Last Charge consumption. Here's the current view of Trips and energy over the past 5 miles:
    edehuhaz.jpg

    9ujuhe9u.jpg

    The weather has gotten cooler but not overly so, and the car is garaged at home and work. I have the climate on range mode and set at 68 degrees. I usually drive targeting the kW needle between 20 and 40, and in the past couple of days aiming even lower. But the consumption is still way up. I've rebooted both screens and have a call in to service, but in the meantime, any ideas or similar experience among TMC members?

    Thanks in advance for your help.
     
  2. mknox

    mknox Well-Known Member

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    My guess is the "colder" weather. My Wh/mi numbers shot way up as soon as the temperatures got below about 50 degrees. I got my car in early March and was getting higher Wh/mi numbers initially and was quite shocked to see how much the numbers dropped once the weather warmed up. It makes a HUGE difference.
     
  3. mkuendig

    mkuendig Member

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    try with a complete reboot of the car. go in park, controls, e-brake, power off. wait 2 minutes.

    start car again.

    also check pressure in tires. I'm down by 5% with filling the tire pressure to spec.
     
  4. mknox

    mknox Well-Known Member

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    I don't believe that will "re-boot" the car. That action is the same thing that happens when you just get out of the car and close the door. You can re-boot the center console (which seems to control an awful lot of stuff) by holding down both scroll wheels until the screen goes dark. I doubt, however, that it would do anything to fix higher energy consumption.
     
  5. rdrcrmatt

    rdrcrmatt Member

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    within the first 10 miles of any days driving the Wh/mi reading is always way high. It basically starts at infinity, not zero. So your first few miles make the averages look way off.
     
  6. PeterK

    PeterK Model S Owner

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    I think it may be a combination of this and Mknox's points. I've driven relatively little in short trips in the past week, which hasn't given it much time to warm up. May need to adjust my charge start time so battery is warm in the am. Thanks.
     
  7. Cottonwood

    Cottonwood Roadster#433, Model S#S37

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    Exactly! This is especially true with many short trips. The Model S expends a fairly large amount of energy to get the cabin and battery warmed up. Below 50˚F., the battery really wants some heat. On longer trips, this is not as big an effect, because maintaining temperatures at moderately cool temps is not that costly. Its that big dose of energy for the initial warm-up averaged over a few miles that gets you. Garaging the car does not help a lot unless the garage is heated.

    If you have shore power, you can get rid of a lot of this by using the App to turn on the cabin heater, and forcing charging to start 15 minutes or so before departure. One way to force battery charging to start from the App is to turn on "range" charging. Don't worry, you won't add many miles in 15 minutes, but the car will warm up the battery on shore power. I only do this on long trips where I am pushing the real range on the battery, because there are no real gains in energy savings, only accounting and display gains.

    I have seen exactly the same effects here in Colorado, as the afternoon temperatures went from the 70's on Sunday to the 30's, yesterday and today.
     
  8. scaesare

    scaesare Active Member

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    #8 scaesare, Oct 29, 2013
    Last edited: Oct 29, 2013
    Thanks for starting a thread on a subject I was also considering posting about. :)

    I've also noticed higher-than-normal usage for the last 2 weeks or so. Even though the temperature has dropped only gradually, I suspect that it's crossed the threshold where the car needs to use the electric pack heaters for at least an initial portion of the trip. Temps for me have gotten in to the 40's in the evenings.

    For me, the amount of energy is rather slight thus far: energy averages in the mid-300's of Wh/mi, whereas for the previous 4.5 months it had been right around 300. I've specifically not used the cabin heater on several occasions just to see if that was the primary culprit. Even with it off, the energy is increased, so I suspect it's the pack heater.

    As an interesting aside, the additional energy usage appears to to be reflected in the "Since last charge" counter on the dash trip meter, but not in my rolling average on the "Energy" center or dash screens... perhaps it's time to update my Energy Accounting thread...
     
  9. ElSupreme

    ElSupreme Model S 03182

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    I think the magic number is also 50 degrees F. I have had a few days with significant energy increase (310Wh/mi to about 370 Wh/mi), running the exact same route I do every day.
     
  10. mknox

    mknox Well-Known Member

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    In my case, I have a roughly 40 mile (each way) commute with a few extra miles each day for good measure. I always use shore power to condition the car before I leave in the morning, but don't have that opportunity at work. The high spike at the beginning certainly does drop down, but even so I'm seeing 50 to 100 additional Wh/mi numbers on my "Since Last Charge" display at the end of my 80 to 100 mile day. And it isn't really even "winter" here yet. In the summer, even with a/c on and driving 70 MPH+ on the freeway, I'd be at 290 to 300 Wh/mi at the end of each day. Now with temps in the 40's and 50's I'm seeing 350 to 400 on the exact same daily drive. This is consistent with what I saw when I got my car in early March, so I'm not complaining... it's just a fact with EVs and colder weather.

    I expect a lot of folks in northern states or Canada who got their cars over the summer are going to be a bit surprised at this.
     
  11. brianman

    brianman Burrito Founder

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    Just a data point regarding the underlined...
    Highest I recall seeing is 2574 Wh/mi. about 3 blocks from my house (heading to work). I wasn't paying attention quickly enough to get a camera shot though.
     
  12. gaswalla

    gaswalla P4201/85/airsusp/pano/19i

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    my consumption went up by 10-20% when I got new tires (same Goodyears, bought and installed at Tesla SC).. now it's back to my normal consumption, about a month later. Funny that OP also had tire work. I think it's related to tire pressure.
     
  13. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    Tire pressure is certainly going to affect energy use. What I do when it's cool/cold is to charge and heat as soon as I wake up. This gets the battery and cabin warm so that it doesn't have to heat up during the drive. If your target charge is 210 (as an example) set the timed charge at 190. Then when you wake up, charge the rest of the way. Select range mode with the App and stop charging when you reach your target. You're not really doing a range charge, but the App only has two settings.
     
  14. yobigd20

    yobigd20 Well-Known Member

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    Cold weather. Mine shot up 50-100kW for the past few days bc its 30-50 degrees in the mornings now.
     
  15. woof

    woof Model S #P683 Blue 85 kWh

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    Welcome to Winter in an EV! Got the snowflake in the BMW today for the first time in quite a while...(that means outside temp is less than 37 degrees F). To EV drivers it means "kiss the summer range goodbye".
     
  16. PeterK

    PeterK Model S Owner

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    You might gain energy savings if you timed the basic overnight charge to wrap up just before leaving in the morning. Assuming the simple fact of charging warms up the battery, or that the electric pack heaters run during charging, then you would only warm the pack up once vs. warming it up while charging in the middle of the night, then again before leaving for work.

    I agree the cold must be the culprit, and 50 degrees some kind of tipping point. I got the car in early March but was traveling a lot on business until May so didn't drive it as much in the cold - and had forgotten what kind of numbers I was getting back then, which were further elevated by frequent demonstrations of the acceleration!
     
  17. scaesare

    scaesare Active Member

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    Above 50 degrees this morning. My commute energy usage is right back to it's normal ~300Wh/mi rate.

    Also right at 30 mile mark, my odometer energy average, and the center console 30mi average were only 4wh's apart...

    It does appear that 50 degrees is the magic number...
     
  18. Todd Burch

    Todd Burch Electron Pilot

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    Note also that the Wh/mi in the "Since Last Charge" section includes energy usage from vampire losses. When you start driving, the energy lost while your car was parked is included, and when divided by a small number of miles can yield a higher Wh/mi average.
     
  19. paulkva

    paulkva Member

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    I have to wonder if the firmware version might affect this. I know 5.0/5.6 is supposed to address some of the "vampire drain" issues. I haven't experienced many cold days in DC yet, but so far I haven't noticed any correlation between Wh/mi and outdoor temperature. It's definitely something I'm concerned about for a potential upcoming winter road trip with no superchargers (yet) between here and Pittsburgh.
     

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