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Never ending Supercharge?

Discussion in 'Model S: Battery & Charging' started by steilkurve, Aug 14, 2015.

  1. steilkurve

    steilkurve Member

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    I've noticed a few times now on road trips that Supercharges take forever to finish. The battery will get to its maximum (a mile or two shy of its published maximum by the way) with the mention "calculating time remaining" and just seems to sit there. Except once shortly after I got the car in March, I've never had the patience to let it finish and just drive off. I understand a Supercharge slows down quite a bit towards the end but is this what you're experiencing too? My range charges at home do end up finishing though I don't monitor them as much (mostly overnight charges) and can't say if they get stuck on the 'calculating time remaining' mode.
     
  2. stevezzzz

    stevezzzz R;SigS;P85D;SigX

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    Totally normal, steilkurve. No matter the maximum charge rate of the charger you're using, the rate declines asymptotically to zero as the battery nears 100% SOC. It's just more noticeable at a Supercharger since the initial charge rate is so high.
     
  3. Brass Guy

    Brass Guy Member

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    If you read the current it's getting at the end, you'll see it's in the single digits. It is the same on a HPWC or UMC. It's really never worth waiting at a supercharger for the last mile, it'd take less time leaving at 99% and driving 1mph slower.
     
  4. TexasEV

    TexasEV Active Member

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    Even better to leave between 80 and 95% unless your really need the extra few miles of range. It takes about as long to go from 80-100% as it does from 0-80%.
     
  5. manis

    manis Member

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    From what I've read, and after talking to someone that knows quite a bit about all of this, it is balancing the batteries and adjusting algorithms. There are threads about this, but by letting it sit and having them balance out the car will know more and you will see a very small increase in your estimated range. When I first got my car I did this. Originally I would see 226mi @ 90%, and after balancing I would see 228mi

    As far as the time it takes to finish. I watched the entire time and I saw it go from 5min left at 99%, hit 100%, then it sat for another 35 minutes going back and forth between 5 minutes and checking remaining time.
     
  6. steilkurve

    steilkurve Member

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    Ok. Thanks all. Assumed as much but wanted to make sure.
     
  7. dsm363

    dsm363 Roadster + Sig Model S

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    Do you need the 100% range for these Supercharge sessions you're doing? As others pointed out you'll save time taking off at 80-90% or so. If you need the range then of course charge to 100% but that last 20% takes a long time.
     
  8. steilkurve

    steilkurve Member

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    Good point. A lot of times I'll need that 100% as I drive to destinations with limited charging options but in other cases, I can get by with 90 or even 80. Thanks.
     
  9. TexasEV

    TexasEV Active Member

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    If you want to do this, let the car do this at home overnight, not at a supercharger. It's not certain that battery balancing even happens when supercharging, but even if it does and assuming the other stalls are empty, is that how you want to spend your time on a road trip?
     
  10. SW2Fiddler

    SW2Fiddler Bannd Member

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    #10 SW2Fiddler, Aug 15, 2015
    Last edited: Aug 15, 2015
    ImageUploadedByTapatalk1439649463.005575.jpg

    No Dr. House, Steve's right. Not worth waiting for the last few % as the Supercharger amperage tapers down below what a Level 2 charger can supply.

    I don't like "+1" posts much, but in this case I really want to say +1 !!
     
  11. manis

    manis Member

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    Wouldn't the concern doing this overnight be that it would sit at 100% too long? I totally understand not doing it on a road trip because it is a huge waste of time.
     
  12. steilkurve

    steilkurve Member

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    Well no. You can calculate how long the charge will last and schedule it to start accordingly.
     

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