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 or making a Paypal contribution here: paypal.me/SupportTMC

OK to leave USB charger plugged in 24/7?

Discussion in 'Model S: Battery & Charging' started by eco5280, Mar 31, 2015.

  1. eco5280

    eco5280 Member

    Joined:
    Mar 27, 2014
    Messages:
    620
    Location:
    Country
  2. brianman

    brianman Burrito Founder

    Joined:
    Nov 10, 2011
    Messages:
    15,487
    Nitpick: I would call this a 12V accessory rather than a "USB charger".

    Answering your question though, I suspect you're fine.
     
  3. Canuck

    Canuck Active Member

    Joined:
    Nov 30, 2013
    Messages:
    3,923
    Location:
    South Surrey, BC
    I have one like this that I plug into the cigarette lighter and run the cord between the passenger seat so it sits on the floor in the middle of the backseats for my kids to use:

    Fonus Brand Two USB DC Cup Holder Cigarette Lighter Socket Power Adapter Splitter Double Car Charger Center with Dual Charging and USB Ports for Apple Iphone 5 (GREEN Dash Sticky Mat is included): Amazon.ca: Electronics

    I sit it in one of these cup holders:

    2007 2014 Tahoe Suburban Avalanche Yukon Console Cup Holder 19154712 | eBay

    I keep it plugged in all the time with no problems.
     
  4. Johan

    Johan Took a TSLA bear test. Came back negative.

    Joined:
    Feb 9, 2012
    Messages:
    6,890
    Location:
    Drammen, Norway
    Yes I do it, no problem. The USB ports are switched anyway (i.e. power to them is cut off when the car is off). Even disregarding this you'll be fine. I have dashcam hard wired to non-switched (always on) fuse and I left it on for 10 days at the airport (forgot to turn it off) in parking mode and no problem with my 12V battery after that either.
     
  5. Bulletproof

    Bulletproof Vendor

    Joined:
    May 9, 2014
    Messages:
    245
    Location:
    Hawthorne, CA adjacent to the Supercharger & Desig
    We've never had a problem with leaving USB cables plugged in, or with any other EVs we tested. I'm sure the same applies for ICE cars.
     
  6. brianman

    brianman Burrito Founder

    Joined:
    Nov 10, 2011
    Messages:
    15,487
    Sometimes the nitpicks are important. The OP is asking about the vehicle's 12V plug not the USB ports.
     
  7. Johan

    Johan Took a TSLA bear test. Came back negative.

    Joined:
    Feb 9, 2012
    Messages:
    6,890
    Location:
    Drammen, Norway
    So very right you were to point that out earlier. Still I missed it. The answer will be the same though for the 12V plug: it's switched too.
     
  8. CHG-ON

    CHG-ON Still in love after all these miles

    Joined:
    Jun 24, 2014
    Messages:
    2,754
    Location:
    Santa Cruz Mountains, USA
    12V and USBs have no power when the car is off. You are totally fine.
     
  9. FlasherZ

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

    Joined:
    Jun 21, 2012
    Messages:
    7,019
    I like to joke with people who ask me about the headlights staying on for a while or leaving an accessory outlet item plugged in: "The battery might go dead. In a month or two."
     
  10. eco5280

    eco5280 Member

    Joined:
    Mar 27, 2014
    Messages:
    620
    Location:
    Country
    I know that - I'm wondering if putting a constant 4.8v draw on the 12v battery while the car is on is damaging to the 12v battery.
     
  11. CHG-ON

    CHG-ON Still in love after all these miles

    Joined:
    Jun 24, 2014
    Messages:
    2,754
    Location:
    Santa Cruz Mountains, USA
    Sorry. I would think not. That is not that big of a draw, considering that the main pack is constantly charging the 12V.

     
  12. ChrisPDX

    ChrisPDX Member

    Joined:
    Mar 19, 2013
    Messages:
    158
    Location:
    Hillsboro, OR
    The adapter is actually pulling 12v from the port. Internally it drops the voltage down to 5v for the USB ports. So as far as the car is concerned, it's a 12v device pulling up to 24watts of power (assuming both USB ports are used at full capacity). I believe Tesla rated that port at 120watts, so you'll have no issues.
     
  13. hpjtv

    hpjtv Member

    Joined:
    Jul 5, 2014
    Messages:
    60
    Location:
    Langley, BC, Canada
    The USB ports are always ON (Dec 2014 Model S) contrary to what everyone is saying. Only the 12V outlet is switched off when the car powers off. How do I know this? I have a constant USB charger plugged in one port and the light is always on (the cables with the LED at the tips), the other plugged into my lithium-ion battery pack which I connect to my cell phones and the unit says it's always charging. I've gone as far as plugging a dead tablet into it and come back hours later to find that it is fully charged. Since my dash cam uses 5V, I will be wiring it to the USB also now. And yes it is okay to keep accessories plugged in. If the 12V dips below a certain voltage, the main pack charges it back up.
     
    • Informative x 1
  14. FlasherZ

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

    Joined:
    Jun 21, 2012
    Messages:
    7,019
    If true on your car, this is a change from earlier cars. My USB ports and accessory outlet all shut off when the car is off. In my Signature car, the USB ports are limited anyway in that they're only 1.0A ports, so we keep a charger plugged into the accessory outlet.
     
  15. jerry33

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

    Joined:
    Mar 8, 2012
    Messages:
    12,748
    Location:
    Texas
    My earlier car takes a few minutes to shut off. If you don't check, it might appear that it stays on.
     
  16. snellenr

    snellenr Member

    Joined:
    Aug 5, 2013
    Messages:
    255
    Location:
    Houston
    Sure - but it only works out to around a 176 ft/hour charging rate. A HPWC would be better...
     
  17. RiverBrick

    RiverBrick Active Member

    Joined:
    Mar 23, 2014
    Messages:
    1,365
    Location:
    Québec

    In my car they go off if and only if I check the energy saving boxes which put the car into a deep sleep.
     
  18. hpjtv

    hpjtv Member

    Joined:
    Jul 5, 2014
    Messages:
    60
    Location:
    Langley, BC, Canada
    I have the energy savings on but with Always Connected checked. Yes, I know the accessories take a bit to turn off once you lock/leave the car but my USB remains on all the time. My dash cam records 24/7 (it uses 5V) only when connected to the USB, not the 12V which turns off.
     
  19. jerry33

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

    Joined:
    Mar 8, 2012
    Messages:
    12,748
    Location:
    Texas
    If I plug my phone in and turn the car off, it charges for one or two minutes (I've never actually timed it, but it shuts off before I get bored of waiting) and then stops. Energy savings on, Always connected off.
     
  20. hpjtv

    hpjtv Member

    Joined:
    Jul 5, 2014
    Messages:
    60
    Location:
    Langley, BC, Canada
    Maybe keep always connected on and see what happens. I'll have to experiment with both and get back on this. It also looks like your vehicle is pre-auto pilot so there might have been some changes made.
     

Share This Page