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J1772 Charging for the Tesla Roadster

Discussion in 'Supercharging & Charging Infrastructure' started by tomsax, Sep 14, 2010.

  1. tomsax

    tomsax Member

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    Upon further correspondence with those involved, it sounds like the adapter they used may have just been a J1772-to-Outlet adapter.
     
  2. TEG

    TEG TMC Moderator

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    #42 TEG, Sep 19, 2010
    Last edited: Sep 19, 2010
    A J1772 to NEMA 14-50 with mechanism to cut off power if it didn't get at least a Level 2 6.6kW pilot signal would be sort of the universal stop-gap converter for a whole range of "legacy" vehicles.
    Many EV owners (me included) have already come up with a NEMA 14-50 plug for our charging equipment. It would work with the RFMC and Tesla mobile chargers too.

    (With that said, I hope to find a J1772-2010 male to J1772-1996/Avcon male adapter cable so I don't have to drag a bulky secondary EVSE box to hook to new public charge spots. Basically it is ultimately preferable to go from EV standard to EV standard so you can use the source EVSE's pilot signal instead of having to generate one externally.)
     
  3. TEG

    TEG TMC Moderator

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    Hey nice find!
    !B3YG,1Q!mk~$(KGrHqYOKioE)WIWeZflBMl-E6hU2Q~~_12.JPG
    !B3YGSRwB2k~$(KGrHqEOKnIE)399ZHleBMl-EWJj3g~~_12.JPG

    It doesn't have the "disconnect interlock if the pilot signal isn't strong enough for the EVSE plugged into the other side", that I was recommending, but if you know what you are doing it is a useful device.

    Disclaimers seen on the eBay listing:


     
  4. mpt

    mpt Electrics are back

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    Me too

    Here's my go at the adapter; I'll be testing it tomorrow.

    J1772 to Tesla finished.JPG J1772 to Tesla open.JPG
     
  5. mpt

    mpt Electrics are back

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    It worked!

    The guys at the parking lot were glad to see us "This is the first car I've seen on my shift" he said as he moved two cars out of the way to make room for me to get in. The lot is a typical NY car park; they park the cars so have the keys to move things around resolving the question of what happens if someone else takes the spot.

    The cheaper plastic J1772 socket on my adapter felt like more of an occasional device; good enough but if I converted the car I'd install the better metal socket.

    Initially I had a few GFI trips as the car began to charge but remedied that by unplugging everything, then plugging the J1772 into my cable, then the cable into the car in that order. I can only speculate as to why but wonder if I didn't have a sound connection with the plastic J1772 socket initially.

    Hold the ChagePoint card up to the charger and the screen scrolls the message "Authorizing..." then ready.

    Once charging, I noticed that, as with Tom's charging event, the voltage was unusually low; 202v in my case. As the source is current limited that mean that I was only seeing 6KW compared to the 7+ I get at home on the 232-243v feed I see. Where did my extra volts go I wonder?

    I used the ChargePoint iPhone app to monitor progress as I sat down with John Voelcker of HighGearMedia at a local coffee shop; that guy knows his EV world from both sides of the detroit fence and dispenses it freely and with alacrity.

    As you can see from the attached screen shot, the service sends out SMS messages when/if the car shuts off but nothing came whilst we were waiting.

    When I returned to the car, the connector box had a hint of warmth but certainly nothing to raise an alarm. The car; still charging.

    I rolled up the cord and hung it back on the charger; interesting to speculate how the cable will look like in a couple of years when less vigilant users have been in town.

    So, did I need to charge? No, this was a test
    Will I use it again? I don't plan on parking anywhere else when I visit the city!

    J1772 test - location.JPG J1772 test - cable.JPG J1772 test - charging.JPG J1772 test - Chargepoint app SMS.PNG J1772 test - Chargepoint app.PNG
     
  6. AndrewBissell

    AndrewBissell Member

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    MPT: How did you source the Tesla connector? Is it easy to wire into?
     
  7. mpt

    mpt Electrics are back

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    Sorry, the Tesla connector is an ex. MC240... The severed end of the MC240 will get a male J1772 in due course to create a useful road-charger.
     
  8. AndrewBissell

    AndrewBissell Member

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    Thanks. Interesting approach.
     
  9. jkirkebo

    jkirkebo Model S P85+ VIN 14420 EU

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    Hmm, sounds like the chargers was fed from a 208V 3-phase supply ?
     
  10. mpt

    mpt Electrics are back

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    That would make sense as the third phase would drive the 120v charging feed; the charger has one level one and one level two output that can operate independantly.
     
  11. tomsax

    tomsax Member

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    Very nice! Thanks for the awesome report.

    I hadn't registered my ChargePoint card when we did our test, so I couldn't try the monitoring and notification features. It's great to see that in action. This functionality solves the problem of the charge stopping and the owner not finding out about it until hours later, which relieves us from babysitting the car during road trip charging.

    It's going to be awesome when we all have access to thousands of these chargers!
     
  12. tomsax

    tomsax Member

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    #53 tomsax, Sep 25, 2010
    Last edited: Sep 25, 2010
    Safety Note

    These pass-through adapters are great for demos by careful, educated owners, but it's probably worth noting that because the Tesla cable/plug came from a mobile connector, it's limited to 30A (if from an MC240) or 40A (RFMC or UMC). This is adequate for the majority of charging stations being installed with the government grant money.

    However, in the long term, we'll want full Level 2 J1772 stations installed for faster Roadster charging (at 70A). I think it will be easier for us to talk businesses to put in these chargers, that will also work with the Nissan Leaf, Chevy Volt, Ford Focus, etc., than it is to get someone to install a charger that only works with Tesla Roadsters.

    If you use one of these homemade pass-through adapters at one of those stations, the charger will tell the Roadster it can charge at 70A, and there's no way for the car to know it's unsafe to pull that much current through the adapter. Pulling too much current will silently overheat the adapter and possibly cause a real problem (melting, shorting, burning) unless the owner intervenes and lowers the current.

    It's really going to be best for all of us if we wait until there's a full 70A J1772-to-Tesla adapter, or a full 70A J1772 conversion option for the Roadster before we start using the J1772 chargers.
     
  13. folsomev

    folsomev Member

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    We need to keep the public small-paddle chargers for some time to come. There's no practical way to convert a RAV4 EV or other inductively charged vehicle to J1772, short of carrying a 70-lb charger around.
     
  14. Fuzzylogic

    Fuzzylogic Roadster Sport 2.5 & S100D

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    I just cut the cable from my MC240 too, for use with an adaptive charger i'm building.
    It will measure the current on the Phase, and calculate the max current for the roadster.
    We have 3x25A here, and i want to use the max 25A, without the risk of tripping/blowing the main fuse.

    anyway, i noticed that the main wires on the cable are AWG8. shouldn't they be able to carry atleast 40A? (not really important for me, but it could help you guys)

    Is there a guide or instructions on how to take apart the Tesla plug?
     
  15. tomsax

    tomsax Member

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    The cable on my RFMC uses 6 AWG wire, and my HPC uses 4 AWG wire. According to this Wikipedia article, 8 AWG wire is rated for 40 to 55 amps, depending on the insulation. (I haven't looked at the reference cited in the article.) When wiring electrical circuits, you're required to stay at or under 80% of the rated amperage for extended loads. Perhaps the same applies here, using 40A wire for an hours-long charging session at 32A.

    Even if the wire is good to 40A, the contacts in the plug may not be. I believe the contacts in the MC120 plug have to be upgraded to handle 40A.

    I am not aware of such a document, but would be very interested if there is one. Martin's documents on the RFMC do not cover that.
     
  16. richkae

    richkae VIN587

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    I am pretty sure that when taking apart an MC120 plug and upgrading it to become an RFMC the pins in the plug are taken out, the wire is removed, the pins are bored out to accomodate the 6 AWG wire, then those wires are inserted.
     
  17. dwegmull

    dwegmull 2013 Model S 85

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    Tom: Are the RFMC documents still online?

    I have taken the car side plug of my MC120 apart. Before I go into more details, please note that this is not an easy thing to do. I requires the use of many tools including some hard to get / purpose built ones. Taking the MC240 plug apart might be a bit different. Most parts that make up the plug are plastic or aluminum: use steel tools carefully or risk scratching and damaging the plug!

    I took some pictures after I had it apart: http://wegmuller.org/v-web/gallery/MC120TearDown (the gallery has two pages).

    Here is my best recollection of the sequence (in these, I call the end of the plug that goes into the car the front and the end from which the cable emerges, the back):
    1) Unscrew the plastic cable retaining nut (six sided nut from which the cable merges).
    2) Unscrew the plastic retainer from the Aluminum six sided back of the plug. You are now done with the easy part.
    3) Holding the main outer casing (the black cylindrical part you twist as you insert the plug into the car), unscrew the back aluminum six sided "nut". This may require significant torque as you will have to break thread locking compound (glue for metal). In theory, thread lock can be loosened by applying heat. Considering that the inner part of the plug is plastic, this may not be a good idea... There are three small springs that are in the end of the inner grey plastic core: remove them at once or loose them forever!
    4) Now things get interesting. Using a piece of bent wire, carefully pull the seal from the front of the plug. The seal is like an O ring, only with a rectangular section.
    5) You should now see a brass ring with six holes and three cutouts. You need to unscrew this ring from the core of the plug. The way I did it was to make a "wrench" by turning a couple of pins that fit in the holes but have a step to prevent them from falling through. Now that I've seen the inside of the plug, I think simple strait pins would do. Diameter is 2.6mm. A length of about 40mm should work well. My pins were a bit short, requiring the use of tweezers... The reminder of the "wrench" is a piece of flat steel bar about 3mm thick (1/8") and 19mm wide (3/4"). I bent it into a U shape, so it would fit inside the "trench" between the outer case and the plug core. Using a large adjustable wrench, I applied torque to the U shaped steel piece which in turns pushed on the pins that rotated the ring. On the inside of the outer case there are three brass pins (the ones that grab on to the car socket): they prevented my tool from turning all the way around, requiring frequent reset of the pins, using all three pairs of holes in the ring. To keep things interesting, the ring threads are held with lock tight. There is also a wavy washer spring behind the ring: it creates the friction for the rotating part. I suspect that the ring is torqued at a very specific setting when the plug is assembled...
    Here is a picture of the tool installed on the ring, outside of the plug, for clarity: http://wegmuller.org/v-web/gallery/albums/MC120TearDown/IMAG0225.jpg
    6) Getting the ring out of the plug will require you to line it up so a cutout in its threads (inside diameter) clears the index on the core of the plug. Then you have to align the rotating body so the ring will clear the three pins that extend inward from said body. That's when three cutouts on the outer diameter of the ring body come in handy.
    7) Unscrew the screw located in the middle of the grey sliding latch on the outer body. This requires the use of a "security" Allen wrench. This particular wrench is like a regular six sided allen bit, but with a hole drilled through its core. Those bits are not usually found in hardware stores. I borrowed mine from work. It came part of a set manufactured by Wiha of Germany. The bit that worked for me is a 5/64" Tamper Resistant Hex. There was, however, quite a bit of slop which leads me to believe the correct size is metric, possibly 2mm. You should be able to remove the grey sliding part. Some sliding and twisting of the outer core might be needed to free it completely.
    8) Under the grey plastic part, there is a white plastic part. Between it and the outer casing there is a small spring (the exact same kind as in step 3). Remove said spring and twist the outer body until the white plastic piece lines up with a cutout in the plug core. It should be now possible to slide the outer casing towards the front of the plug to reveal the core.
    9) Towards the rear of the grey plastic core, there is a small electrical switch. (it is the one that let the car and charger "know" the plug is ready and secured). Two wires extend from the switch following a channel in the grey plastic core. At some point the wires disappear under a blob of silicon. Carefully pry off the silicon. Mine came out in three or four pieces.
    10) Now we reach a point where things might be a bit different for the MC240 compared to the MC120: the two wires from the switch (blue and black) are soldered to a purple and a green wire coming from the contacts. The solders are protected with heat shrink tubbing. There is enough slack in the wires to pull their connection points out of the rear of the plug. Cut the black and blue wires off right at the base of the heat shrink tubbing. I aslo removed said heat shrink tubbing to be ready for the eventual re-assembly. Now pull the wires out of the grey plastic core.
    11) You can now slide the grey plastic core away from the metal front core. This may require some "convincing" as it is a pretty tight fit.
    12) The previous step unveiled a black inner metal core. This part is screwed into the front metal part. Once again you will have to fight the thread-lock. The only way I managed to get it unscrewed was to hold the black part in a wise (with flat, non marring, jaws!) and, using a copper rod as a punch, hit the small locating tab (it held the grey plastic core in place).
    13) On the side of the front inner core, there is a small Allen screw. Undo it and you will free the contact carrier out of the front inner core. Congratulations: you have now taken appart a Tesla plug!
     
  18. Kevin Sharpe

    Kevin Sharpe Active Member

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    I don't think it's that simple. I'm not sure the pins used in the MC120 plug can handle 70 amps safely. They're "standard" Radsok contacts made by Amphenol and if I remember correctly the current handling capacity varies a lot between different pin types.
     
  19. Fuzzylogic

    Fuzzylogic Roadster Sport 2.5 & S100D

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    Thanks dwegmull for your detailed explanation and pictures.

    I have the Wima security bit, now i need some courage to take it apart, and extend the cable.

    I just looked at both the MC120 and MC240 plugs, atleast from the outside, the Radsok contacts look identical.
     

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