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Preventing Vampire Drain!

Discussion in 'Model S: Battery & Charging' started by jlucero, Mar 27, 2016.

  1. jlucero

    jlucero Member

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    how does one do this the best way? turn energy savings on and uncheck always connected? is this all i can do? im in a situation where i cannot charge everyday, maybe only twice a week, so i want to make sure minimal drain overnight. please provide your experiences in the best way to handle this.

    thanks!
     
  2. CHG-ON

    CHG-ON Still in love after all these miles

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    I think that's about all you can do. Tesla says that we should only lose about 1% of charge per day in temperate climates, 3% in cold. Though I have read of others losing more.
     
  3. jlucero

    jlucero Member

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    That stinks. i thought i read somewhere that you can almost put the car in deep sleep and where there is no drain, but when you start the car up, it takes time to get out of sleep mode.
     
  4. TexasEV

    TexasEV Active Member

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    What stinks? If you can't tolerate losing 1% charge per day (or up to 3% on very cold days in winter) you may need to rethink how you're using the car.
     
  5. jlucero

    jlucero Member

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    well last night, i lost 2.5% over 12 hour period. i had 230 miles and 224 when i got back in the car 12 hours later. temperature outside was 55-60 degrees. i guess this is just technology that will be improved upon as time goes on. im just not accustomed to this as i used to have a constant charging every night so didnt experience this. just sold my house, so im in a rental now, trying to deal with precious miles.
     
  6. brkaus

    brkaus Active Member

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    Any chance you can get 120v standard outlet?
     
  7. dennis

    dennis P85D

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    If you have the settings correct (energy savings on and always connected off) then there is a problem with your car not sleeping. You should only lose 3 miles of range in a 24 hour period if your car is sleeping correctly.

    One way to check this is by accessing the car with the iPhone/Android app when you think the car is asleep. You should see "Waking car" for 1-2 minutes before the app gets connected. If you don't it means the car was not asleep and you should contact Tesla tech support so they can pull the logs for your car and figure out what is not working.
     
  8. mblakele

    mblakele radial cross member

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    Also try disabling "Smart Preconditioning" if it's enabled. From the manual: "If on, Model S predicts your driving schedule and automatically adjusts the temperature of the cabin based on your last set temperature and your driving schedule, making Model S comfortable and ready to drive."

    For me this seemed to burn another 1-2% overnight. That's just a rough estimate, though: I didn't experiment before I turned it off.
     
  9. jlucero

    jlucero Member

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  10. jlucero

    jlucero Member

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    thank you! i will try that as well! great suggestions!
     
  11. jlucero

    jlucero Member

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    FYI, trying that Smart Conditioning disabling helped out alot! lost one mile last night on 187 miles!
     
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  12. Ingineer

    Ingineer Electrical Engineer

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    You could also put a switch on the 12v battery. With the 12v battery disconnected the car will not lose any range, though it will also not heat the battery if it gets too cold in the winter.
     
  13. Electric700

    Electric700 Active Member

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    If you disconnect the 12 V battery, I think the car also will not cool the battery when needed in the summertime. It's probably best to avoid modifying the car in this way if possible.
     
  14. tnt1971

    tnt1971 Member

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    I have almost 3,000 miles on my 85D after two months of ownership and I am surprised at the "lost" energy. My car is plugged in more than 20 hours a day during the week, although I try to do 90%+ of its charging at work. Every other weekend I go away and it sits outside Friday to Monday, unplugged. My rough estimate is that it loses about 10Kwh per week unrelated to driving. I get to this by subtracting the Kwh used in the energy meter versus the actual drop in battery percentage (I can tell when I charge it).
    I have read here that this is worse in the winter, and I have not had my car in the really cold weather yet. Rough calculations this is about $120 in lost electric per year at 20 cents per Kwh (likely to be worse in winter). Multiply this by 150k vehicles and it is a large loss. It must be a difficult problem to fix or else they would have fixed it.
     
  15. Boatguy

    Boatguy Member

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    What happens if you power down the car over the weekend?
     
  16. tnt1971

    tnt1971 Member

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    If you are referring to the energy savings settings, I use that on the weekends I am away. It helps. I leave the "always connected" setting checked. Even with that, I stand by the 10 kWh loss per week. I notice it even loses charge when plugged in (not charging, of course).
     
  17. Boatguy

    Boatguy Member

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    My mistake, I though the option under E-Brake would completely power down the car, but it does not.

    I have the Energy Saving ON all the time, but leave Always Connected ON, and I still lose 4-6mi/day which is 1-2 kWh/day so easily the 10kWh you see in a week.

    Extrapolating to a year and 150,000 cars = 10kWh * 52 * 150,000 = 78 mWh/year for the fleet, or at least $1B in electricity costs for the entire fleet. That's a lot of wasted electricity Mr. Musk!

    Back to the OP, Energy Saving ON and Always Connected OFF is apparently all that can be done to limit vampire loss.
     
  18. jerry33

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

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    Right, the option under E-Brake does almost the same thing as if you walk away from the car.

    FWIW, I leave Always Connected OFF.
     
  19. Boatguy

    Boatguy Member

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    Bad math. 78mWh/year is only $12M / yr.
     
  20. tnt1971

    tnt1971 Member

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    My math says you are using about 15 cents per kWh. On Long Island, I am paying about 18 cents. In Queens (a NYC suburb), it is between 25 and 30 cents. I would imagine the places were Teslas are prevalent are on the way high side of the electric cost scale. In short, your dollar number is low.
     

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