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Regen Below Limit Today

Discussion in 'Model S: Battery & Charging' started by Todd Burch, Mar 25, 2013.

  1. Todd Burch

    Todd Burch Electron Pilot

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    After work today I started driving home and noticed something a bit odd.

    It was about 34°F and I had a limited regen arc (yellow dashed arc around 30 kW) because the pack was cold. However, as I was regenning (if that's not a verb we should make it one) I noticed that I was only regenerating at 15 kW instead of the 30 kW limit, despite regenning from a high speed (50 mph).

    Any ideas as to why I would have significantly less regen than even the yellow arc limit was indicating, despite slowing from a fairly high speed? No, I was not using the brakes.
     
  2. eelton

    eelton Member

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    I've noticed this before as well. I assume that, when cold, regeneration is proportionally reduced, not just capped.
     
  3. Todd Burch

    Todd Burch Electron Pilot

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    That seems silly. Why not cap? You'd be throwing away a lot of energy if true.
     
  4. K Hall

    K Hall Member

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    Battery performance is reduced when its cold. It's a common occurrence.
     
  5. Todd Burch

    Todd Burch Electron Pilot

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    Yes I know. Check the post again. I believe you misinterpreted the question.
     
  6. ggr

    ggr Roadster R80 537, SigS P85 29

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    Any noun can be verbed.
     
  7. Todd Burch

    Todd Burch Electron Pilot

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    Well played, well played.
     
  8. K Hall

    K Hall Member

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    ah I see. It might not be a governor but a indicator of limitation. The yellow line that is. It could be a miscalculation.
     
  9. Doug_G

    Doug_G Lead Moderator

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    The yellow line is always shown too high. In fact, even when it is not shown at all you can still be limited to 50 kW regen. Then as the pack warms up further you finally get the full 60 kW.
     
  10. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    Even when my yellow line is gone, I notice regen can be limited to 30 or 45 kW.
     
  11. strider

    strider Active Member

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    You could also have been traction-limited. Tires don't grip as well in the cold and the car will adjust regen based on available traction.
     
  12. Todd Burch

    Todd Burch Electron Pilot

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    I was nowhere no a traction limit, so don't think that was an issue. Clear, dry pavement, and less braking force than standard regen.
     
  13. wjhepworth

    wjhepworth Member

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    I have noticed the same effect. Seems to be related to temperature. It has happened a couple times to me so far this winter and it seems to stay there until temps rise. My follow up question would be around the fact that I thought the car kept the batteries warm. I am guessing they keep the battery "just warm enough" to avoid wasting energy.
     
  14. scottm

    scottm Active Member

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    regen'ing
     
  15. Todd Burch

    Todd Burch Electron Pilot

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    Was I enduring the process of regenification?
     
  16. whitecotton

    whitecotton Member

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    I hate to bring back this thread but an important thing to realize Is when you drive in the cold all the cold wind is hitting the bottom of the battery pack so it might actually cool the pack just enough to push you to the next threshold of regen limits until it warms up again.
     

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