TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker and becoming a Supporting Member. For more info: Support TMC

Does leaving just the pigtail plugged in use electricity?

Discussion in 'Model 3: Battery & Charging' started by runelind, Dec 14, 2019.

  1. runelind

    runelind Member

    Joined:
    Dec 10, 2019
    Messages:
    100
    Location:
    Denver
    I have a 14-50 outlet in my garage that I will use from time to time when I need to top up the car. Knowing that the outlets are not rated to be plugged and unplugged constantly, I was thinking of leaving just the pigtail plugged in and connect the UMC when needed. Does having just the pigtail plugged in use any power or will it just sit idle?
     
  2. M3BlueGeorgia

    M3BlueGeorgia Active Member

    Joined:
    Dec 10, 2018
    Messages:
    1,249
    Location:
    Atlanta, GA
    1) Trivial, not worth worrying about

    2) Why are you routinely packing your Mobile Connector?
    People with 240v sockets normally just leave the mobile connector attached to it and only unplug from the wall for a road trip.

    But get a hanger for the Mobile Connector to keep it off the floor, such as:
    Cable Organizer
     
    • Like x 3
    • Helpful x 1
  3. Kevy Baby

    Kevy Baby Dis-Member

    Joined:
    Aug 11, 2019
    Messages:
    1,520
    Location:
    Brea, CA
    In my case, 95% of my charging is at work on a 14-50 outlet that I share with a coworker with a Volt. I'm currently figuring out a way to get a second cable that I can somehow leave plugged in and locked in the cabinet.
     
    • Like x 2
  4. Akikiki

    Akikiki A'-Lo-HA ! y'all

    Joined:
    Nov 26, 2012
    Messages:
    5,894
    Location:
    Kaneohe, HI
    Good idea to take the stress off the UM's "knot". I used a bicycle water bottle holder I got on Amazon. Perfect form factor for the knot to fit into. Found one on Amazon for about $10.
     
  5. runelind

    runelind Member

    Joined:
    Dec 10, 2019
    Messages:
    100
    Location:
    Denver
    I’m in a similar boat where I’m expecting to do most of my charging at work and only use the 14-50 at home when I need extra range, hence why I was asking about leaving the pigtail hanging at home.
     
  6. Jeff32

    Jeff32 Member

    Joined:
    Apr 11, 2019
    Messages:
    47
    Location:
    Grand Rapids, MI
    OP... I agree with M3BlueGeorgia.. trivial, if any cost/flow of energy.

    I have an unrelated question. Tesla recommends, in cold weather driving, to always leave the car plugged in when not in use. They don't say to always "charge" the car when not in use. So, does the battery draw a small bit off the UMC, short of actual charging, while plugged in to power?
     
  7. jjrandorin

    jjrandorin Moderator, Model 3, Tesla Energy Forums

    Joined:
    Nov 28, 2018
    Messages:
    5,811
    Location:
    Riverside Co. CA
    The car will use shore power while plugged in to do anything it feels it needs to do (update checks, heat the cabin, ensure the batteries dont get too cold, etc etc).
     
    • Informative x 1
    • Like x 1
  8. evM3Sekar

    evM3Sekar Member

    Joined:
    Mar 31, 2019
    Messages:
    57
    Location:
    Cincinnati, OH
    The car may draw small amounts of power occasionally ... for its maintenance. Leaving it plugged in is significantly better than worrying about this small but necessary consumption.
     
  9. Jeff32

    Jeff32 Member

    Joined:
    Apr 11, 2019
    Messages:
    47
    Location:
    Grand Rapids, MI
    It's not the consumption that concerns me, rather, I want to do what's best for the battery. Is the battery "happiest" when it is run down to 20%, charged to 80% and plugged in to the UMC every night for necessary consumption? Not that I can accomplish this, just trying to understand ideal maintenance.
     
  10. BE_M3

    BE_M3 Member

    Joined:
    Aug 2, 2018
    Messages:
    48
    Location:
    Morgan Hill CA
    I leave my UMC plugged in 24-7 and attached it to the wall no no strain on the cord. Bought another one for travel. 14-50 outlets are not made to be plugged in and out like a 115v outlet. Leaving the pigtail plugged in and hot connected to the UMC is dangerous being Its a live 240v connection.
     
    • Like x 1
  11. jjrandorin

    jjrandorin Moderator, Model 3, Tesla Energy Forums

    Joined:
    Nov 28, 2018
    Messages:
    5,811
    Location:
    Riverside Co. CA
    No, not according to specific direction in the manual that comes with the car, anyway. It specifically says there is no benefit to doing exactly what you just described.
     
    • Informative x 1
    • Like x 1
  12. StealthP3D

    StealthP3D Well-Known Member

    Joined:
    Dec 12, 2018
    Messages:
    7,930
    Location:
    Maple Falls, WA
    Leaving it plugged in will reduce the cycling of the main battery. The car draws 12V from the lead acid battery for computers, Sentry Mode, etc. which needs to be charged periodically. If it's not plugged in it will charge the 12V battery using the main battery.
     
    • Like x 1
  13. Akikiki

    Akikiki A'-Lo-HA ! y'all

    Joined:
    Nov 26, 2012
    Messages:
    5,894
    Location:
    Kaneohe, HI
    Elon and Franz have always said, "A happy Tesla is a plugged in Tesla.".
     
  14. srs5694

    srs5694 Active Member

    Joined:
    Jan 15, 2019
    Messages:
    1,024
    Location:
    Woonsocket, RI
    I think a lot of people are misinterpreting the intent. I read the above as saying that the Mobile Connector will be going with the car regularly, but that the plug/adapter from the Mobile Connector to the NEMA 14-50 outlet will be left plugged into the NEMA 14-50 outlet. This is not, as I read it, a question about leaving the car plugged into the wall outlet (via the Mobile Connector).

    If I'm correct in my interpretation of the question, then there should be no current draw from the plug/adapter; it's basically just an extension of the wiring in the wall, and unless something is wired into it, no electricity will flow as a result.

    That said, unplugging the plug/adapter from the Mobile Connector on a regular basis will put wear and tear on it. I don't know how many such cycles the Mobile Connector can take. My guess is that it can take many more cycles than a cheap NEMA 14-50 outlet, but maybe not that many more than a higher-quality outlet; and it'll be much more expensive to replace a Mobile Connector if it should fail.

    Personally, if I needed to use my own EVSE to charge at work, I don't think I'd bother. I guarantee that it'll get old very quickly to have to pack and unpack the Mobile Connector, plug it in, etc. Doing so in inclement weather will be even worse, and runs some risk of damaging the Mobile Connector, which is not rated for use in rain and snow. Of course, you could avoid charging at work in bad weather, but that defeats the monetary advantages of doing so (I assume that's why you want to charge at work), at least on days with bad weather.
     
    • Like x 1
  15. runelind

    runelind Member

    Joined:
    Dec 10, 2019
    Messages:
    100
    Location:
    Denver
    I'll be inside a parking garage so no risk of inclement weather. I agree about dealing with the mobile connector, but we'll see how I feel about it after a while.

    And yes, you are correct about my intent about only leaving the pigtail connected. I will hopefully do 90% of the charging at work since I'll be ending up with a net+ number of miles after the commute. We'll see though, may just get a second UMC for home and do most of the charging there.
     
  16. MorrisonHiker

    MorrisonHiker S 100D 2020.44.15

    Joined:
    Mar 8, 2015
    Messages:
    8,706
    Location:
    Colorado
    #16 MorrisonHiker, Dec 16, 2019
    Last edited: Dec 16, 2019
    You could ask your employer if they could put in a Tesla HPWC or a standard J1772 charging station. Then you wouldn't need to worry about using your UMC and other EV owners could use the charging station as well.

    My last employer had 36 J1772 charging stations so I charged my Model S there weekly. They became quite popular so they put in even more charging stations and eventually had to start charging for them since there were hundreds of EVs needing to use them.
     
    • Like x 2
  17. davewill

    davewill Active Member

    Joined:
    Feb 5, 2014
    Messages:
    1,763
    Location:
    San Diego, CA, US
    There's no advantage to transferring the wear to your UMC instead of the outlet. Just unplug it from the wall and keep an eye on your outlet...or get a second charging solution (wall connector or another mobile connector) to permanently leave at home.
     
    • Like x 1

Share This Page

  • About Us

    Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.
  • Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


    SUPPORT TMC