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Model S Battery Question

Discussion in 'Model S' started by Emilyjane, Dec 5, 2018.

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  1. Emilyjane

    Emilyjane New Member

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    Los Angeles
    I have a model S. The other week while driving a 40mile drive I started around 220miles. The miles were RAPIDLY dropping near the end of my drive. For every mile I drive about 10miles were taken off my miles left to drive. I arrived with less than 65miles on my battery for a 40mile trip. Mind you I saw this and turned off the AC and it still kept draining like crazy.

    Now I live in an apartment complex and my boyfriend thinks it’s very bad to charge the Tesla overnight (as I’m leaving it plugged in all night) he said it can be bad for the battery and may be why we were losing so much battery life that one day.

    Could that be the reason? Is it really bad for the battery to be charged overnight or be plugged in after it’s hit it’s full charge?
     
  2. Tam

    Tam Well-Known Member

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    Owner's manual wants you to plug in:

    [​IMG]

    Elon Musk tweeted the best is 30-80% charge. You should not charge your lithium Tesla battery all the way to 100% full charge unless you will drive it off pretty soon.

    The most power hog is SPEED and worse together with headwind.

    Climbing up elevation also consumes lots of power but you should gain some back on the way down.

    Heater and subfreezing weather also consume lots of power.
     
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  3. wdolson

    wdolson Well-Known Member

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    In winter driving, the car will use more energy than in warmer weather. If you have the heat on, that's a drain, but also if the battery is cold, it will warm the battery to get it up to a better operating temperature. You said you had the AC on and I see you live in Los Angeles, so that is probably not the problem.

    I take it you have some experience with the car (ie this wasn't the first time you drove it). If the state of charge drops faster than expected and you aren't running the heat, that might be an indication the battery pack has developed one or more bad cells, or something else has gone wrong with the pack. I recommend you take it in to the service center, but document how much energy it used to take and how much it's taking now. Some people have had problems convincing the service center the pack was failing.
     
  4. ckoval7

    ckoval7 Mild One

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    Tesla's are not cordless drills. The rules for the battery are very different. A plugged in Tesla is a happy Tesla. The car takes very good care of it's own battery.

    Your location says LA, so I'll assume cold weather was not an issue. Even then, you shouldn't have used that much power. I strongly recommend giving Tesla service a call. They can remotely diagnose your battery and get it replaced if you have cells going bad.

    What was your WHr/mi for that trip? Have you driven it since then?
     
  5. wdolson

    wdolson Well-Known Member

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    BTW I've left my car plugged in every night for over 2 years (except for a few nights on the road) and my battery's 90% is still within 1 mile of range of when it was new. I leave mine set to 90%. I've only gone above that a few times and then driven it right away. One time the service center set it to 100% and I didn't notice until it had charged to about 98% at home. I unplugged the car and ran the heat for about 1/2 an hour, that brought it down to around 90%.
     
  6. MaryAnning3

    MaryAnning3 Supporting Member

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    Location:
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    What if you have to leave your car unplugged (and undriven) for a week or two, Do you think it is okay to charge to like somewhere between 50% to 65% and then just leave the car parked without external power for a week or two? What is the ideal protocol for that scenario?
     
  7. dark cloud

    dark cloud Active Member

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    It took you 155 miles of range to travel 40 miles? That is too much. If I drove at -20 degrees Celsius, up the steepest hill I can find, full speed, towing a boat in a strong headwind I don't think it would be that inefficient. Maybe a brake caliper is seized badly? Any strange noises? But I would be able to tell this just from the feel of the increased drag/accelerator pressure and increase in regeneration. The a/c is not going to make that much difference.

    Did this just happen once? or is it repeatable?

    I would give them a call, as ckoval7 suggests, they should be able to tell you if there is an issue.
     
  8. ckoval7

    ckoval7 Mild One

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    I think there are a few threads about this already. The general consensus is that your car will lose about 1 to 2% per day when it just sits idly. The car puts itself in a low power sleep state and will be ok as long as you don't log into the app and check on it all the time. Once the battery drops below a certain percentage (not sure of the exact number) the car will go into an ultra low power deep sleep and won't wake up until you're there with the key fob. I would charge it to 80% and then just not worry about it.
     
  9. TexasEV

    TexasEV Well-Known Member

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    If only new owners would RTFM. Especially the battery section.
     
  10. ewoodrick

    ewoodrick Well-Known Member

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    As some women are prone to say.

    Stupid boyfriend
     
  11. FoxSTL2HOU

    FoxSTL2HOU Member

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    HOU
    As previously stated, OP needs to offer up some more info to give better insight on this occurrence, which is absolutely out of the norm (155 mi used * 300 wh/mi rated / 40 mi driven = 1162.5 wh/mi usage!!).

    Age of vehicle - any natural battery degradation?
    Battery size - 75/85/90?
    Weather conditions - sounds like a nice day in LA?
    Terrain - level on the 405, or heading up in elevation to the high desert?
    State of Charge - had battery been sitting at 100% SoC consistently?
    Extra battery draw - using a 110v AC adapter or something off the wall?
     

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