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Leave plug connected overnight?

Discussion in 'Model S: Battery & Charging' started by n33d45p33d, Mar 22, 2015.

  1. n33d45p33d

    n33d45p33d Member

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    Hey guys, just picked up my Model S today. I'm charging at home with the NEMA 14-50 at 30 miles an hour. Of course the car will be fully charged sometime in the night, is it ok to leave the plug connected to the car and wall outlet all night?
     
  2. Stoneymonster

    Stoneymonster Active Member

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  3. TexasEV

    TexasEV Active Member

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    Yes, you are supposed to keep it plugged in when possible. The cars used to be delivered with cards that say "A connected model S is a happy Model S." Plug it in when you get home, unplug it when you leave in the morning, and don't think about it otherwise.
     
  4. EVSE Solutions

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    The concept of keeping your car ALWAYS plugged in is good if you have the ability to connect everywhere you go, but it is not necessary if you can remember to plug in before the car becomes lower than say.. 50%. If you keep the battery SOC 50 to 75 percent a majority of the time; your battery will have a healthier overall life cycle.
     
  5. Larry Chanin

    Larry Chanin Model S Perf Sig 1055

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    Storing the car for long periods of time at a state of charge at around 50% will put less stress on the battery than at a higher state of charge. However, without knowing how much daily driving an owner does, it is questionable if we can reach any definitive conclusions regarding whether it is healthier in letting the state of charge dip toward 50%. What we do know is that shallow charging cycles that do not approach full capacity are going to be less harmful than deep charging cycles. So if someone does a moderate amount of daily traveling it may be both impractical to try to maintain a state of charge near 50% and even if if were done it may actually cause a situation where the charging cycle is deeper than it needs to be and therefore less healthy for the battery.

    Returning to the original posters question "..., is it ok to leave the plug connected to the car and wall outlet all night?", as others have said the answer is definitely yes, and plugging in when the opportunity presents itself it will result in shallower charging cycles which is inherently good for the battery so as long as the charging is not approaching the full capacity.

    Larry

    - - - Updated - - -

    Congratulations.

    If you are interested in joining a Florida Tesla club, please click on the link to Florida Tesla Enthusiasts in my signature.

    Larry
     
  6. David99

    David99 Active Member

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    Yes keep it plugged in whenever you can. The misconception is that every electronic device that has a battery starts charging the moment you plug it in and will not stop until it's full. We all know charging to 100% isn't good for the life of the battery. The Model S doesn't do that. It charges only to the level you set it to and then uses grid power just to keep the battery happy. It will run the coolant pump here and there to make sure all cells have the same temperature. Keeping it plugged in allows you to remotely start or stop charging and when you turn on the AC or heater it will use grid power instead of the battery.

    So yes, keep it plugged in, even if you are not charging.
     
  7. mikeash

    mikeash Active Member

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    Just to be a little more specific about what happens when you plug in....

    When you first plug in, the car will start charging, and will continue to charge until it reaches the charge limit. You can set the charge limit in the charging screen in the car, or in the smartphone app. I believe the default limit is 90%.

    Once it hits the charge limit, the charge stops and the wall voltage is disconnected. I believe you'll hear some relays click when this happens, although I haven't been present for the event myself. At this point, the car acts more or less as if it were unplugged.

    Now, if the battery charge drops by more than a certain amount (not sure exactly how much, but a few miles of rated range) then the car will reconnect to the wall voltage and charge back to the set limit.

    Similarly, if you turn on the climate control (either using the app or by opening the door) the car will turn on the wall voltage (if it's not already on from charging) and run the climate control from the charging power rather than the batteries. This means you can pre-heat or pre-cool the car without impacting range if it's plugged in at the time, which is really nice. Also saves some wear on the batteries, for whatever that's worth.
     
  8. CHG-ON

    CHG-ON Still in love after all these miles

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    Absolutely. Keep her plugged in.
     
  9. austinEV

    austinEV Active Member

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    Also, if your utility offers lower rates at night, you can set the car to start charging later. Also kinder to the grid, and maybe a cleaner mix.
     
  10. rickgt

    rickgt Enthusiast owner/member

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    yes, you have a really smart car... it charges at the time you tell it, and stops at the limit you set... uses the power plug for "vampire" drain outside that time... No harm no foul...

    PS; don't know about Florida, but CA has special EV rates that are terrific if you charge after midnight.
     
  11. HankLloydRight

    HankLloydRight Fluxing

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    For long term storage while plugged in, what's the optimal SOC to leave it set at? My car has been hibernating all winter at about 50% SOC.
     
  12. djp

    djp Roadster 2.0 VIN939

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    You're doing the right thing for long term storage. Leave it plugged in with the slider at 50% SOC.
     
  13. David99

    David99 Active Member

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    But why? Why not use this awesome car? :)
     
  14. Bobbyducati

    Bobbyducati Member

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    whats the optimal setting for daily use? my commute/daily mileage is less than 20 miles, i usually limit it around 80% for daily charging.
     
  15. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    70% to 80% would be just fine for your driving habits. There's a big jump in longevity from 100% to 90%, much less of a jump from 90% to 80%, and still less from 80% to 70%.
     
  16. n33d45p33d

    n33d45p33d Member

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    Thanks for the replies guys. Leaving it plugged in all night and might start plugging in at work also.
     
  17. Andyw2100

    Andyw2100 Well-Known Member

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    I know you were trying to be helpful, but there's some inaccurate information here.

    For starters, the car may or may not start to charge when you initially plug it in, depending on whether or not timed charging is set. It is possible to turn on timed charging, and have the charging start at a specific time. This is useful if you have night rates, and also if you want the charge to end close to the time you want to depart.

    Also the battery won't just start to charge again due to the range dropping a few miles of rated range. I believe if the car is plugged in it will charge as most every two days.
     
  18. caddieo

    caddieo Member

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    My daily use is about 40 miles (+/- 10). My charging slider is set to about 155-160 and charging is programmed to start at 0015 hrs at 20 amps. Days with longer trips are usually known ahead of time and allow me to reprogram charging to >200 miles or whatever and up the amps to 40 from 20. On a few unexpected long driving days I am fortunate to have superchargers ~40 miles in either direction (N and S). YMMV. :smile:
     
  19. mikeash

    mikeash Active Member

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    I figured the explicit starting time would be an obvious exception (since you have to set it up) not necessary to call out.

    As for charging again while plugged in, that's not been my experience at all. I've woken up to notifications on my phone saying the car topped off in the middle of the night, after charging to full the previous evening and staying plugged in.
     
  20. Andyw2100

    Andyw2100 Well-Known Member

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    Since the OP started out by asking a really basic question about whether or not it is OK to leave the car plugged in all the time, I figured it was better to be explicit about the timed charging, as he might have had no idea that it was even an option.


    That certainly interesting. My car has only "topped off" if it's been plugged in without being driven for a few days.
     

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