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Charges only once per plugin?

Discussion in 'Model S: Battery & Charging' started by Dstrohl, Dec 25, 2016.

  1. Dstrohl

    Dstrohl Member

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    It appears that the Tesla only will charge once per time it is plugged in... (without a workaround).

    I plugged my car in after work and it charged to 90%. The next morning my daughter asked me to take her to school so I pre-heated the car, then she didn't need the ride (and I forgot to turn off the heating for a little bit). I later noticed that the car was down to 87% charge. Not horrid, but it's a few percent. So, I poked through both the Tesla app and the Remote S app, and there did not seem to be any way of starting a new charge. I poked my head in the car as well and nothing there seemed to indicate that I could restart the charge either.

    The workaround that I found (other than unplugging and re-plugging it in) was to change the charge limit, at which point the car immediately started charging.

    So, am I missing something? It was not critical there, but it seems like if I have the car plugged in it should keep the charge it's set to (perhaps using wall power while plugged in or something.)

    Thoughts? working at intended? known bug? call the SC immediately, the car is about to burst into flames?
     
  2. DrivingRockies

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    It will charge again after a set drop. I think 3-4%, but don't quote me.
     
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  3. ecarfan

    ecarfan Well-Known Member

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    My experience is that my car can go through multiple charge sessions without reconnecting the charge cable. I have not had the issue you describe.
     
  4. Saghost

    Saghost Active Member

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    Mine went for three days without rebuilding the vampire drain - then recharged somewhere on the third day (the longest it has ever sat plugged in without me driving somewhere.) Not sure exactly what the logic is yet.
     
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  5. Canuck

    Canuck Active Member

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    I've noticed this too lately and it never used to do that so they must have changed something in the software.
     
  6. Saghost

    Saghost Active Member

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    Fewer thermal cycles on the charging hardware? I'm not sure what else they gain from it as a change.

    I think my X has been this way since I got it on 7.1 in August but I'm not 100% sure since I didn't notice it until one of the early 8.0 versions.
     
  7. Electric1

    Electric1 Member

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    My s 2013 (6xxx) never restarts charging on its own. Never has. BTW I have an "a" pack
     
  8. TexasEV

    TexasEV Well-Known Member

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    #8 TexasEV, Dec 25, 2016
    Last edited: Dec 25, 2016
    What the OP experienced is perfectly normal. The car doesn't continuously charge to make up for vampire drain (which is what it seems to be as people don't usually preheat the car and then not drive it). After three days it will charge up to the set point again. There is no practical reason for the car to maintain the charge within such a narrow tolerance while plugged in-- it would require the charger to run too often. If you really need the extra 3% in that situation, you could increase the charge setting as you did, or unplug and replug in the car.

    Also, asking if the car is about to burst into flames isn't appreciated if you want people to take your question seriously.
     
  9. DrivingRockies

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    I appreciated the joke...
     
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  10. Dstrohl

    Dstrohl Member

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    That makes sense, and it doesn't bother me, as you said, I can get that 3% back really quickly if needed, I just wanted to make sure that it was operating as designed.

    Sorry, I was trying for sarcasm and apparently failing <grin>, though in the end, I would rather people didn't take me seriously than them take me too seriously. It's generally a happier place to be! (outside of my profession that is).
     
  11. UberEV1

    UberEV1 Member

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    I frequently travel out of the country, leaving my 2013 plugged in and usually set to 70~75% while I'm away. It takes 3~4 days to trigger another charge cycle back to the set-point, but it does work. As posted above, it drops 3~5% of charge before triggering a re-charge. Even after 2 weeks of travel, the car is always within 3~5% of the setpoint.
     
  12. ig_epower

    ig_epower Member

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    I am about to do this myself for the first time. Normally when I travel for 5 days, it is on business and I take the car to the airport parking lot. I watch the SOC remotely and see the small decline over time. Tomorrow, I plan to leave my car for 12 days but I will park it at home. No one else will use it while I am away. I will set the timer to start after 7pm (for the cheapest electricity), charge level to 50%, and current to about 20A (50% of what my HPWC is capable of delivering). If I had time, I would have added a float charger for the 12V battery as well but I will forgo it this time. Have I forgotten anything? I will set it to power save mode but "Always Connected".
     
  13. andrewket

    andrewket Well-Known Member

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    The software is working as designed. If the SOC hasn't gone down by ~3% from the set point it will not charge. As you discovered, a way to trigger the car to charge now is to change the set point. You can even immediately set it back once it starts charging.

    If it didn't have this grace zone the car would constantly cycle charge on/off as the car is always consuming energy.
     
  14. andrewket

    andrewket Well-Known Member

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    Do not add a float charger. The car has its own DC to DC step down transformer. Let the car do its own thing. Everything else you stated is fine. 50%, scheduling charging, save energy mode, and leave it plugged in. Note that if you remotely check on your car that you're also waking it up.
     
  15. ig_epower

    ig_epower Member

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    "Do not add a float charger. The car has its own DC to DC step down transformer. Let the car do its own thing."

    Actually, the internal charging cycle lets the 12V battery drop to 50-60% of it's capacity before the contactors engage the HVP to do their thing. Over a course of a day, the battery can cycle like this 5 or 6 times when not in power-save mode (probably/hopefully less in power save mode). The float charger would keep the 12V from draining and allow the electronics in the car to remain active when needed. I'm not sure if the act of preventing 60 - 70 cycles over 2 weeks on the battery will amount to any significant improvements on improving the longevity of my battery but some other people are floating their batteries for just this reason.
     
  16. andrewket

    andrewket Well-Known Member

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    And when the car measures 14v at the battery because of the external power source and throws an error?

    To each is own, but I've left my car for several weeks doing nothing more then I described above and didn't have any problems. Tesla engineered the car to deal with these situations. Why not trust that and keep your warranty :)
     
  17. ig_epower

    ig_epower Member

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    I can't say I disagree and hence I am not losing any sleep over it (float charge issue on the 12V). I did forget another setting - put it on Valet Mode. Just in case someone figures on how to hack into my car, they won't be able to turn off the remote monitoring in case I have to go find my car....
     

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