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Smart preconditioning vs. phone app

Discussion in 'Model S' started by fasteddie7, Dec 14, 2016.

  1. fasteddie7

    fasteddie7 Member

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    Is there a difference? Every morning I have been charging to 90% then preheating for 45 mins while charging to 100% right before I leave for work. It's around 5-10 degrees fahrenheit so I still have the dotted line and reduced regen with the occasional banging of the breaks coming loose from being frozen. Does smart preconditioning do any more, such as heating the underbelly getting the battery to the right temp for no limits regen or windshield wiper heating or is it the same as the app? One would think the seats and wipers would be in app, but that could be an update, I just wondered if smart preconditioning was better than me just using the app. I've read on here also that if your schedule varies it doesn't always work the best, any experience from those who work odd schedules?
     
  2. thimel

    thimel Member

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    Smart preconditioning only turns on the heater or AC. It tries to do it for when it thinks you will drive the car. Even people with regular schedules find it doesn't work well and use the App to turn on the climate control. If you want the battery to warm up, make sure you have range mode turned OFF. Also, if you schedule charging to finish shortly before you leave, that will help make the battery warm.
    And, no, their is no way to schedule an end charging time. You have to estimate how long charging will take and set the start time.
     
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  3. CHG-ON

    CHG-ON Still in love after all these miles

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    Also, if you are charging to 100%, the battery can't take regen power becaused it is full. It needs to bleed off some charge to be able to accept more. I'm not sure if you need 100% every day or not. If you don't, you will get better life out of the battery if you can approximate what you need, with a buffer and try to only charge to that level, give or take. There was a post sometime back where a battery engineer said the best charging level for long battery life was between 30-70%. 70 works for me most of the time, so I have been following that advice. I can't tell about battery health, but my range has stayed very consistent since I started doing that. I have also read quite a bit about Lithium batteries not liking to be fully charged and fully drained repeatedly. I am lazy about that with my Mac and just had to replace the battery.

    5-10 degrees. Yuk! I'm so glad I left CT for CA!:cool:
     
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  4. fasteddie7

    fasteddie7 Member

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    I have a software limited 60d so I get regen at 100%.
     
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  5. BBB4000

    BBB4000 Member

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    Is this real? I just got my 60d this week and am scared to charge to 100%
     
  6. fasteddie7

    fasteddie7 Member

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    I've never had my range or display show over 100% but I live on a hill and it just stays at 100 a little longer showing me -kWh for a short bit. I doubt you could actually charge the vehicle to 75 kWh but my understating based on tmc forums is the 60 is actually 62 and a little kWh but I'm not sure if that has anything to do with it. The jury is still out on if a 60 is a top limited 75 making 100% of a 60d - 80% of the 75 in real life. But I only do the whole 100% on my long commute days in the extreme cold and leave almost immediately after I hit it.
     
  7. Ojas Ray

    Ojas Ray Member

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    I also picked up my 90d just last week - and i charge to 90% every night -- when speaking with the Forman at the Tesla service -- they told me even if i keep range mode ON -- turning on the climate from the app will heat the battery -- range mode ON only reduces the power in the heat for the cabin....

    not sure what is true or not...
     
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  8. Andyw2100

    Andyw2100 Supporting Member

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    Unless there has been a change in a recent software version, you were given bad information. In the past, with range mode on, turning on climate only heated the cabin. With range mode off, the pack would also be heated.
     
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  9. Ojas Ray

    Ojas Ray Member

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    And that is EXACTLY what I thought -- but the forman at the Tesla service told me to click on the "i" next to the range mode and he read it off to me. It clearly states range mode only affects cabin.

    I am not sure what is what...
     
  10. CHG-ON

    CHG-ON Still in love after all these miles

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    Agreed. They may have changed it. But I haven't read anything here to to say that it has changed. Easy enough to test though.
     
  11. Andyw2100

    Andyw2100 Supporting Member

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    How would you test unless you have some software or something that will tell you the temperature of the pack? It seems the regen limit when cold has definitely become more aggressive, so when it's cold I seem to be regen limited unless I have just charged, and even then sometimes. What I'm saying is that I can't use the regen limit to determine whether or not the pack was heating when the cabin was or not.

    Interested in hearing how you plan to test.

    Thanks!
     
  12. Brass Guy

    Brass Guy Member

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    Range mode turns off battery heating when not plugged in, but while plugged in that may have changed. The test wouldn't be too difficult. In a cold morning, go out and unplug the car, sit and turn it on with the brake and check the regen limit in the display. Check range mode, plug it back in, go inside where it's warm and preheat the car, then check the limit before you drive. Let us know how much it changed, I don't want to go out there.
     
  13. Andyw2100

    Andyw2100 Supporting Member

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    I already addressed this.

    The regen limit is not a good way to test this definitively.

    I believe some people have access to some of the cars' internals, and they may be able to monitor the pack temperature. That would be the way to know definitively, one way or the other.
     
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  14. whitex

    whitex Active Member

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    Tried preheating the car for over an hour on HI, restarting when needed. Cabin was super hot, melted some chocolate bars, but battery was still cold (limited regen and limited SC).
     
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  15. CHG-ON

    CHG-ON Still in love after all these miles

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    I thought that battery heating only happened with smart preconditioning when the car was plugged in and rage mode was off. Or the car was being charged. I don't need it where I live, so I have never bothered with it since it seemed to be so inconsistent. I would think the way to test it would be to try turning smart P on in range mode and out of range mode and see if anything changes. That, or just forget the smart P and charge the car for an hour when you get up. Though that is pretty inconvenient.
     
  16. EclecticCitizen

    EclecticCitizen House call doctor for families.

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    I get no battery heating during Smart Preconditioning or app use when I am unplugged at work. Smart Preconditioning has only come on twice in the last 6 months, I assume because my schedule differs each day (even though week to week it is nearly unchanged).

    I have tried repeating the climate control cycle for an hour from the app so that the cabin is nice and warm. But the pack remains cold and regen is limited my entire 13 mile commute home (going 50-60mph for most, then 45mpg last 3 miles) so far during below freezing days. Acceleration power is less likely to be limited, but occasionally happens too.

    I think this is by design still, as they want to minimize range loss with pack heating. I wish they'd make it an option for us to control. I am never in range anxiety for my daily commute and would be happy to give up range to get back acceleration and normal regen so that my car drives consistently no matter the outside temp.
     
  17. Andyw2100

    Andyw2100 Supporting Member

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    I think the consensus on TMC is that smart preconditioning basically just doesn't work. It was a reasonably good idea implemented very poorly.


    You probably know this, but just in case...range mode has to be off for cabin heating to also heat the battery.
     
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  18. JHuberman

    JHuberman Member

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    If you want regen to work right away set your charge limit to 80% and do your precondition as you like. Then when you are ready to leave after unplugging set the charge limit to 100% and regen will work just fine. (Play with the percentages to fine tune it for your needs.)
     
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  19. Andyw2100

    Andyw2100 Supporting Member

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    I don't think any of the above is accurate information.

    You can have your charge limit set to anything you want, and as long as the battery has room to accept more power, if regen is available (battery not too cold) regen will work. Setting the charge limit to 100% after disconnecting would accomplish absolutely nothing.

    Also, if regen is not available because the battery is cold, nothing you wrote above will change that.

    Charging a good amount just before leaving will warm the pack, but very possibly not enough to eliminate the restriction on regen. It depends on the temperature and how much heat is generated during charging.

    Warming the cabin, with range mode off, will also heat the pack some, but not very much.

    Just wondering, @JHuberman, what the source of your information was.
     
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  20. Brass Guy

    Brass Guy Member

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    In my experience the battery heater seems to get it warm enough for just over 30kW regen. Even while driving with range mode off it's pretty easy to see on the energy app that the battery heater shut off after about 30kW regen is available.

    In colder weather the only thing that can totally eliminate the regen limit when starting out is driving immediately after charging. I've been setting the charge start time each night based on how much charging I need. I'm charging at 34A (~24mph) which is real close to 10%/hour which makes figuring out the start time easy. If it's real cold, like single digits F, I add about a half hour because charging starts slowly until the battery heats up at least a little.

    You can supplement this idea by setting the charge limit past what you need. For example, if you think you need 80% charge, set the start time so it reaches 80% by the time you're going to leave, but set the charge limit to 90% so it keeps charging until you unplug. Preheat so the cabin is toasty, the battery is toasty, you get a no-compromise drive.
     

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