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USB Port Output

Discussion in 'Model S: Interior & Exterior' started by TheAccuser, Oct 14, 2015.

  1. TheAccuser

    TheAccuser Member

    Nov 20, 2014
    Cleveland, Ohio, United States
    Is there a difference with the output for the two USB ports? I feel like the USB port closest to the driver charges my iPhone 6S+ very slow. I haven't done any times tests yet. Does anyone know the specs of the USB ports?
  2. MrJones390

    MrJones390 Space Boat

    Jun 26, 2015
    Los Angeles
    Here you go: Tesla Model S Fast Charging USB Port Hack -


    I confirmed that both ports on my Model S charge at a rate of 1 amp, and not the 2.1/1 amp that some forum members (myself included) have previously reported. Actual measurements indicate that the PortaPow device is useless in the Model S. Skip it.
    My recommendation is to get a good USB car charger that’s capable of charging at the maximum 2.1A rate. You can pick up a decent charger for under $20 that will actually do the job.
  3. TheAccuser

    TheAccuser Member

    Nov 20, 2014
    Cleveland, Ohio, United States
    Awesome info! Thanks for the link. I ordered this yesterday: Car Charger, [Apple MFI Certified] 3.1A Lightning iPhone Car Charger with 3ft Lightning Cable for iPhone 6s, 6 / 6 Plus / 5s / 5, iPad Air 2 and more by eBuddies (Black): Cell Phones Accessories
  4. JeffVanEpps

    JeffVanEpps Member

    Apr 1, 2015
    Any info on charging rate from the phone mount USB port in the center console? My phone thinks it is charging but it seems to me like the rate might be 0 or even negative.
  5. Jedi2155

    Jedi2155 Model 3 has Arrived.

    Jul 6, 2018
    Diamond Bar, CA
    #5 Jedi2155, Dec 3, 2018
    Last edited: Dec 3, 2018
    I know this is an ancient post, but wanted to report some findings I'm doing on my current loaner while my Model 3 is in the shop:

    I had a rather janky setup but had the following equipment:
    • Drok USB Power Meter
    • Note 8
    • iPhone 7
    • Anker 10000 mah powerbank
    • A variety of USB cables and adaptor
    • 2018 Model S 75D
    Plan on getting a proper USB3.0 extension cable so I can test the front USB ports properly. My existing set of adaptors/dongles causes too much voltage drop due to the increased resistance impacting the tests. I was unable to connect the evice directly to the front USB ports as well due to the shape of the tester. What I did find was the following:

    • Front USB seems to have a greater voltage drop than the rear USB
    • Rear USB can charge up to 1.5A on my powerbank, but all ports seem to limit to 1A on my both my phones
    Front USB -
    Vopen ~ 5.09
    Vload ~ 4.5 to 4.75v (loose connection and or extension cable so...take these values with a grian of salt)
    Max Current ~1 A with phone charging

    Rear USB
    Vopen ~5V
    Vload ~4.9v
    Max Current ~1 A with phone charging, ~1.5A charging powerbank directly. 1A with USB cord

    Check out this dongle monstrosity :D in my attempt to get an working extension cord. Current dropped to a mere 0.3A at 4.5v due to the poor connection and reduced resistance.
    USB Y-Splitter -> Mini to Micro USB dongle -> Micro to USB A dongle -> USB power meter -> USB A to USB C -> Note 8
    I had some other various USB extension cords but all them had some type of obstruction that prevented a proper connection.

    Attached Files:

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