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Reduced regenerative braking at 70 degrees?

Discussion in 'Model S: Battery & Charging' started by patyoungsc, Nov 23, 2016.

  1. patyoungsc

    patyoungsc Member

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    Location:
    Mt Pleasant, SC
    Couldn't find more specific information about when reduced regen is to be expected. I have seen a number of people indicate that when the temperature is low you will have reduced or not regen braking for a while. However, I am seeing that regularly now even when the temperature is high 60s to low 70s. Is that expected? I've only had the car for a couple months and its obviously been warmer, but I figured this would only kick in if it was in the 40s or maybe 50s.
     
  2. thimel

    thimel Member

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    It depends on the battery temperature. So if you leave the car outside over night with a low of 50 degrees and then drive it in the daytime after the air has warmed up to 70, regen may be limited. I don't know the exact battery temperature where regen gets limited.
     
  3. DMC-Orangeville

    DMC-Orangeville 85D and John Deere 5100E

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    The actual code, showing the temperature, is on this forum under another heading (I can't find it). I recall that it's 8C (which is about 46F). At that temperature you will get some loss of regen - shown as a yellow dotted line on the energy App. At colder temperatures, especially if windy and left over night, you will see a total loss of regenerative braking. I saw this once last year (it was a relatively warm winter), at about -15C, which is about 0F.
     
    • Informative x 1
  4. ebrown7b

    ebrown7b Member

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    How recently did you start to notice this change? I've noticed the same since my 2013 P85 was in for service service 2 weeks ago (which included a drive unit swap). Previously, only very occasionally would I see regen limited first thing in the morning and even then it would last briefly (maybe 5 minutes or so). Now, I see regen limited to a lower power (15-30kW) pretty much every day and it seems to last my entire commute (15+ minutes). Most of the days, the temp is in the upper 50s / lower 60s. This morning, it was 58F and the car had been in the sun for 2-3 hours.

    At the same time my car was in for service, the latest FW update was released. I wonder if there were changes in that release that affected the regen limits. Temperatures have been slowly dropping, but the changes in regen limits seem to be more than I would expect. It now regularly affects how I drive the car. The car doesn't slow as expected when letting off of the accelerator pedal.
     
  5. Naonak

    Naonak Member

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    I've noticed a substantial change since v8.0 ... now the loss of regen kicks in much sooner and lasts a LOT longer.
     
  6. aesculus

    aesculus Still Trying to Figure this All Out

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    In the Model X manual it states this:

    So if you have your max charge set to 80% and you get anywhere near that number, the regen will start to lessen. I always thought max charge was 100%, and prior to V8.0, I think it was.

    I suspect the Model S is the same.
     
  7. apacheguy

    apacheguy S Sig #255

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    8 C is the active heating target in pre 8.0 firmware. Regen will continue to be limited at higher temps, however.
     
  8. Naonak

    Naonak Member

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    I don't think that's true, even in v8. My regen will go above my max charge level and it is not limited when I just unplug from charging if I'm not charged to ~98% or more.

    Temperature definitely affects it much more than in v7 for me, though.
     

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