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Initial vampire drain then levels off

Discussion in 'Model S: Battery & Charging' started by jaydee49, Apr 2, 2015.

  1. jaydee49

    jaydee49 Member

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    #1 jaydee49, Apr 2, 2015
    Last edited: Apr 2, 2015
    I've had my S 85 for over a week (absolutely love it) but had a question regarding vampire drain on my car and whether what I was experiencing was normal and/or correctable. I seem to have a high initial drain (possibly because of cooler temperatures) but then it seems to level off after an initial period.

    Weather this week has been pretty much been highs around 70, lows around 50, car parked outside. I have energy saving on, with always connected checked. On version 6.2.

    Car has sat idle for the following periods (all miles below are rated miles):

    Sun 7pm - Mon 7am (12 hours): Lost 5 miles

    Mon 7pm - Tues 7am (12 hours): Lost 5 miles

    Tues 7pm - Thurs 7am (36 hours): Lost 8 miles

    The 36-hour period above broken into 12-hour increments:

    Tues 7pm - Weds 7am (night): Lost 5 miles
    Weds 7am - 7pm (day): Lost 1 mile
    Weds 7pm - Thurs 7am (night): Lost 2 miles

    So the two things I can conclude is that the car (as it should) drains more overnight in colder weather. What I don't get is why after the initial 12 hour period it seems to drain a lot less, even when the temperature is the same. Is this normal, and is there any reason for this? Just wondering if there is a setting I can change or if it's correctable in some way. Not a big deal, but trying to learn more about my car as I go along. Thanks in advance.
     
  2. benjiejr

    benjiejr Technogeekextraordinaire

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    Mine drain is pretty consistent at about 1 mi per 4 hours which seems to be relatively in line with your findings overall. Only thing I can think of why yours is draining more at the beginning is if you happen to have smart preconditioning on and it's trying to condition your battery during those times when the drain is higher than usual. Do you have smart preconditioning on?
     
  3. jaydee49

    jaydee49 Member

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    #3 jaydee49, Apr 2, 2015
    Last edited: Apr 2, 2015
    I have smart preconditioning off. Just seemed odd to me though I don't have a ton of sample size yet to compare.
     
  4. sorka

    sorka Active Member

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    I parked my brand new P85D in the garage Monday night. It's been there ever since as I left on a trip the following morning. It has been losing 3.3 miles every 24 hours which judging from this thread is not that bad, but consider this:

    3.3 miles is roughly 41 watts of continuous draw. More than enough to keep an HID headlight on continuously.

    41 watts an hour from a 12 volt battery is 82 amp hours a day which if the 12 volt battery is a small one like the Prius is only 28 am hours which means the draw is enough to deplete the battery 3 times a day unless the contactors keep closing to top off the battery. Assuming this only happens 6 times a day, the 12 volt battery would be half depleted 6 times a day which would be really really bad for that battery. It would have to be replaced within a year or so. If instead it only allows a 10% reduction before topping off, the contactors would have to close 30 times a day which would be bad for the life of the contactors in the main battery.

    What version of the software do you guys have? I'm still on 6.1. Please tell me that you're not on 6.2 and that the Vampire drain is about to get a lot worse.

    Anyone with 6.2 have any data on this?
     
  5. Candleflame

    Candleflame Member

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    i don't think this whole mile thing is particularly useful, better to check whh loss/ SOC loss.
     
  6. sorka

    sorka Active Member

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    I've been using a VT a few times a day to look at that SOC and it's loss tracks the rated mile loss perfectly.
     
  7. benjiejr

    benjiejr Technogeekextraordinaire

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    Hate to say it, but I'm on 6.2 and I originally replied with 1 mi per 4 hours. It still appears to be the same.
     

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