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J1772 Charging for the Tesla Roadster

Discussion in 'Charging Standards and Infrastructure' started by tomsax, Sep 14, 2010.

  1. tomsax

    tomsax Member

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    We are about to see a mass deployment of public level 2 SAE J1772 charging stations, over 14,000 from The EV Project alone. This compares to fewer than 100 public Tesla charging stations (240V/70A High Power Connectors, aka HPCs). Over the next 12 months, I expect that the availability of level 2 J1772 chargers will totally overwhelm all other charger types.

    While most of these 240V chargers will be limited to 30A or 32A, J1772 chargers capable of supplying 240V/70A are available from Clipper Creek with many other vendors also working on charging stations.

    Teaming up with a number of other Tesla owners and members of the broader EV community, Cathy and I have been looking into what would be required to bring J1772 charging support to the Roadster community.

    The good news is that Tesla and J1772 use the same communications protocol to establish the connection and start/stop charging. This didn't happen by accident. Tesla Motors was involved early on in the development of the J1772 spec. But the Roadster was designed before the new J1772 committee even got going, so the Tesla charging protocol was designed based on the old J1772 specification which used the Avcon connectors and limited charging to 40 amps. Tesla extended this protocol up to 70 amps, and successfully lobbied the J1772 committee to adopt this extension. Cathy and I have confirmed that the SAE J1772 JAN2010 spec exactly matches the amp limit waveforms produced by the Tesla HPC at all amperage limits from 12A to 70A.

    So, the Tesla Roadster uses the same communications protocol as J1772. (Except for the button on the HPC that can be used to start charging; I don't know how that works.) The only barrier to charging a Roadster from a J1772 station is the Tesla plug. We confirmed this by building a proof-of-concept adapter and using it to charge our Roadster at a Level 2 J1772 charging station in Olympia, WA, last Friday (Sept. 10, 2010).

    J1772-charging.jpg

    J1772-touchscreen.jpg

    We'd like to thank Dave Denhart, Rich Kaethler, Chad Schwitters, Martin Eberhard, and Dave Kois for helping us with this proof-of-concept project. Thanks also to Jim Blaisdell of Charge Northwest for helping us find a level 2 charging station and getting us a ChargePoint Network card overnight. Our crude adapter is not a robust solution. As you can see it's quite bulky (since we didn't want to cut the cable to a working Tesla plug) and isn't watertight enough for general outdoor use.

    When the Roadster was entering production, there was no standard J1772 plug, so Tesla had to design their own. That was a necessary step, but now that the final standard uses a different plug, I think we need to find a real solution to this incompatibility. As I see it, there are at least 4 possible solutions:

    1. An upgrade to switch both the Roadster and HPC to use J1772 connectors.
    2. A compact adapter that converts J1772 to the Tesla connector.
    3. A new pigtail for Tesla's universal mobile connector (UMC).
    4. A new pigtail that requires purchasing a re-engineered UMC.

    A new pig tail for the current UMC (solution 3) isn't very appealing as the UMC is limited to 40A, cutting us off from any 70A J1772 chargers, while also requiring us to stuff a large, heavy, awkward cable into our trunks just to charge at a station that is guaranteed to have a cable that will reach our charge port. It's also not nice for those of us who have already invested in a different mobile connector, like the original MC240 or the RFMC. Solution 4 is even worse than 3 as it shares all of the problems and it would require everyone to purchase a new mobile connector.

    A compact adapter (solution 2) is better in that it could support the full 70A charging and also be quite compact, little more than a J1772 receptacle and a Tesla plug. It will still be quite expensive as it requires a Tesla plug. My guess is that it would cost at least $1,200 retail, based on what Tesla charges for the MC240 and UMC. It also has the downside of being an obvious target for malicious theft when the car is left charging unattended. Nissan Leaf owners won't have to leave an expensive, unsecured device dangling from their cars when charging, why should we?

    Full conversion to J1772 (solution 1) sounds radical until you see a J1772 receptacle. It's very close to the size and shape of the inlet in the Tesla charge port. Once I saw that, it required zero imagination to picture a Tesla Roadster with a J1772 receptacle in place of the proprietary Tesla charge inlet.

    The downside of solution 1 is that it would also require replacing the plug on our home chargers (HPC or mobile connector). This could be done by either replacing the cable, or by using the old Tesla inlet and a J1772 cable to make a Tesla-to-J1772 converter.

    The retail cost of an ITT Canon UL-certified J1772 receptacle and cable pair rated for 75A is $825 from Current EV Tech. I don't know of anyone else selling these newly-available connectors, but I do expect it to be a competitive market much larger than just Roadster owners. Even adding in reasonable labor costs, it seems to me that converting a Roadster and HPC should be near or below the cost of a J1772-to-Tesla adapter.

    I have been told that Tesla Motors is investigating ways to bring J1772 support to the Roadster which may include either a compact stand alone adapter (option 2) or a J1772 pig tail for the Tesla universal mobile connector (I'm not sure if this is option 3 or 4). They are early in the process and not promising anything at this point. From what I have heard, Tesla Motors is not interested in providing a full J1772 conversion (option 1) and hasn't even committed to supporting J1772 on the Model S.

    It's possible the full J1772 conversion could be done even if Tesla Motors doesn't give us an official way to do it. I expect our group will continue exploring ideas in case we have to tackle the problem ourselves.

    We are several months away from having a significant number of Level 2 J1772 chargers installed in metro areas targeted by The EV Project, and even further away in other areas of the US. There's plenty of time left for both Tesla Motors and the owner community to explore possible solutions, but I believe this will soon be an important issue for every Roadster owner who wants to be able to take advantage of the soon-to-be pervasive J1772 charging infrastructure to conveniently drive beyond the Roadster's single charge range.

    [This content also available on my blog.]
     
  2. dwegmull

    dwegmull 2013 Model S 85

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    Hi Tom,
    First off, thank you for being a pioneer and confirming that the Roadster is compatible with J1772.

    I have been thinking along the same lines. The main obstacle for me has been the lack of available plug. I'm glad to see them starting to show up at retail. I wonder if we could buy the car side plug only...
    Anyway, I think it would be possible to make a small, rigid adapter that includes a lock. When engaged, the lock would prevent the slider on the TM plug from moving back, so the adapter would be locked to the car. Depending on the J1772 plug size, the adapter could be made of a single aluminum turning.
    Assuming, I would go ahead and make one adapter, I would publish all the drawings so it can be duplicated. Would you be willing (and legally able) to share the details of the electrical connections?
    I have the required tools to machine one adapter but I have no interest in making more. This is why I'm willing to make the details freely available to the community.

    Greetings,
    David
     
  3. ChargeIt!

    ChargeIt! Member

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    YES, thanks!, Tom.

    The RFMC is constructed from an MC-120, which is available from Tesla Motors for $600. Unfortunately tricky labor is involved to upgrade the barrel to 40A, but it's doable, and has been done by Martin and EVComponents.

    I vote for option 2. For on-the-road charging 40A will be sufficient. The Tesla driver would likely also carry his/her existing RFMC or MC240. The additional J1772 pigtail limited to 40A won't take too much space.

    When the cost comes down on the 75A J1722s, those that want it, can either wait, or spend additional $.

    See here: $125 female J
     
  4. vfx

    vfx Well-Known Member

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    #4 vfx, Sep 14, 2010
    Last edited: Sep 14, 2010
    If we are voting (and by the way, thanks Tom!) I vote for #1. We need to clear out all the small paddles, large paddles, Avcons and Tesla plugs from the public charge stations. We are all early adopters. We need to shift to the new standard and not try to stay backwards compatible (unless someone wants to do that in the privacy of their own garage).
     
  5. jasonhi

    jasonhi Roadster 2.5 #1135

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    Nice work Tom!

    When I started talking to Tesla last month before putting my order in, I asked them about the plans for J1772. I had read rumors that they might be planing a conversion to J1772, so I was slightly disappointed to be told that they plan to make some sort of adapter (vs retrofit).

    As a soon-to-be Tesla owner, an adapter will work fine for me. I'll be able to use existing HPC's and new J1772 stations. But it doesn't seem like the best choice for speeding the adoption of EVs at large, or even for Tesla. Ideally the experience of Silicon Valley would suggest that standards help move forward mass adoption of new technology, and supporting legacy systems and technology quickly becomes a liability.

    Any kind of transition is difficult (and expensive), but it only gets harder to do the more time passes and the larger the installed bases become.

    If a transition is assumed, the question comes down to retrofitting the cars and chargers or producing converters. Retrofitting seems more desirable, but possibly more expensive.

    In fact part of the reason I did not order an HPC with my Roadster is because it's not J1772. In a year things may look much different. At a minimum the direction of infrastructure installation will be a lot clearer. Also we'll start to see what kind of EV volumes other manufacturers are able to move.

    ...Jason
     
  6. Doug_G

    Doug_G Lead Moderator

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    Does it? I've only tried hitting it once, but nothing happened...
     
  7. dwegmull

    dwegmull 2013 Model S 85

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    Thanks for the link. I just ordered one. I also started taking apart my 120V plug to see what makes it tick... I will post some updates as I progress.

    Greetings,
    David
     
  8. Current EV Tech

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    I sell both the ITT/Cannon J1772 connectors and sockets and the cheaper version I had made in China.

    http://currentevtech.com/Cables-and-Connectors/SAE-J1772-Connector-c64/

    The ITT/Cannon version is UL certified for 75 amps

    The Chinese version is UL compliant but not yet certified. It is Rated for 70 amps

    You can order the socket and connector as a set or just the socket individually.

    The ITT/ Cannon connector w/socket is $825 --- Socket only is $225

    The Chinese connector w/socket is $475 ---- Socket only is $125

    For European customers I also offer the IEC 62196 connector and socket (the European equivalent of the J1772)

    The Chinese connector w/socket is $475 ---- Socket only is $125

    http://currentevtech.com/Cables-and-Connectors/IEC-62196-Connector-c69/

    I sent Tom the Chinese connector for his initial testing but I would recomend the ITT/Cannon plug as it is UL certified and the quality is a bit better

    Best Regards

    Dave Kois
    Current EV Tech, LLC
    http://www.currentevtech.com
    253-988-5020
    Skype dkoisii
     
  9. PopSmith

    PopSmith Saving for a Model 3

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    I agree with Eric here. The sooner all EVs use a standard plug the better.
     
  10. ChargeIt!

    ChargeIt! Member

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    Thanks for listing, Dave. Wish I had kown earlier ...
     
  11. NEWDL

    NEWDL R#350 R#1323 Sig23 8136

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    Rumor

    I heard rumor of a compact adapter from J1772 to Tesla....

    This was discussed when speaking about charging standards for Model S. If you have a roadster now...and an HPC, what happens when the Model S comes?

    Rumor was an adapter.
     
  12. vfx

    vfx Well-Known Member

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    So just when will Tesla make the transition (if ever)? Will this entire run of Roadsters (to the hold) have Tesla connectors even after there are 20,00 J1772 plugs at malls and curbs are out there taunting buyers of new cars?

    And what about the Model S? Can you even imagine Tesla, a small company releasing a car with a different plug than GM, Nissan, Mitsubishi, and the even smaller Coda? They will get reamed in the press!

    Buyers would have to be convinced that an adapter is OK. The plugs are already on the ergonomic edge of being too big for small hands. Add in an adapter and many women (who are not EV advocates) will be turned off by the process. Tesla is not big on focus groups but this one could cut deep if they don't ask what average car buyers think...
     
  13. mpt

    mpt Electrics are back

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    Tom; fantastic!

    I'd like to see 1. as I agree with VFX but can you imaging the cost; you'd have to take half the car off to do it!?

    Perhaps an adaptive, solid barrel would be the answer, something that would be easy to carry with you; J1772 female to Tesla male.

    An pigtail solution might not be desirable; too short and it's resting on the side on the car, too long and it's laying on the ground in the rain.

    I don't fear that theft would be too much of an issue; the market for stolen adapters will be small (sadly).
     
  14. tomsax

    tomsax Member

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    I'm really glad to hear thoughts from other owners! Keep them coming!

    To be very clear, I'm not recommending anyone jump into the built-your-own-adapter business lightly. I'm certainly not interested in making adapters, beyond doing the one controlled experiment.

    A pass-through connector would have to support the full 80A J1772 spec, otherwise it's too easy to hook the adapter up to a full Level 2 charging station and have the car draw the automatic maximum current and make bad things happen. Even if the builder of the adapter was always conscientious to avoid too much current, someone down the line might grab the adapter and not know about the non-obvious limitation.

    As for upgrading a lower current plug, that's a tricky business. The end of the plug on the MC120 has to be machined out to allow a thicker cable to run through it. The contacts need to be upgraded to support higher current and higher gauge wire, and those contacts are difficult to obtain especially in same quantities. If you build something that has an exposed cable, it needs to be rated for outdoors use, including UV- and oil-resistant. All of this is a big pain and has to be done correctly to be safe and robust, and I'm sure there are other issues I haven't listed here. That's a lot of work to make one adapter.

    I think it would be wise to let Tesla work on finding an acceptable solution for us. If you have thoughts on what that solution should be, I'd recommend expressing them here. If you're a Roadster owner or a Model S reservation holder, I'd recommend also expressing your interest and preference to your Tesla contact person.

    Some responses to the comments so far...

    Adding a lock is an interesting idea, one I hadn't heard before.

    I actually think that's backwards. 70A charging at home is just silly. I charge at 32A and that's fast enough to charge up from my typical daily driving in an hour or two and fast enough for a full charge from empty overnight. It's when you're on the road that 70A charging is handy. If you want to drive 400 miles in a single day, three hours of charging is a lot better than five hours of charging. The difference is even more dramatic if you want to drive 400 miles faster than 55 mph.

    That link is to the cheap J1772 receptacle, like the one Dave Kois donated for the proof-of-concept adapter. I'd definitely recommend the higher quality ITT/Canon receptacle for anything you actually expect to use.

    I've heard more than a rumor, directly from someone at Tesla in the know. As I stated in the original post, Tesla Motors is investigating ways to bring J1772 support to the Roadster which may include either a compact stand alone adapter or a J1772 pig tail for the Tesla universal mobile connector. They are early in the process and not promising anything at this point.

    I don't think it's that bad. You can get access to the inlet from behind the charge port without too much trouble at all. Of course I'm not recommending anyone other than a qualified Tesla service technician do this, just pointing out that it doesn't seem like a big job, and I could be totally wrong.

    The pig tail solution is for Tesla's universal mobile connector. It has a long cord with a Tesla plug on one end and a twist lock connector on the other. The pig tail would plug into the twist lock end, near the charger not near the car. You are right about it laying on the ground though, since you'd have to plug the J1772 cable into it and just set it on the ground. The Coulomb station we tried out didn't have any way to support the J1772 cable up off the ground when plugged into an adapter.

    I don't think anyone would steal an adapter for profit. My concern is malicious theft, someone who objects to electric cars stealing the adapter as an act of vandalism. How would you feel about leaving your car charging through an unsecured $1,600 mobile connector overnight in a lot a couple of blocks from your hotel in a strange city?

    I've never heard of anyone having a problem, but leaving my mobile connector out is contrary to my practice of removing the stereo faceplate and all other valuables from the car when I park in an unfamiliar place.
     
  15. mpt

    mpt Electrics are back

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    That's encouraging, that'd push me more towards option 1. as long as I could remove the Tesla connector from my MC230 and change to a J1772 male; that would be bliss.

    I have the MC230 so it'd be surgery. Though if I understand this, I could remove the GFI/signal generator on in MC230 and install a J1772 female in the empty box.

    Hmm, ok, yeah, now you put it that way. Actually, I was relieved to find that the flashing light on the charge port goes off when you lock the car for that reason.
     
  16. tomsax

    tomsax Member

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    Good point! I had tried it once. While charging, I hit the Stop button. Charging stopped. I then hit the Charge button and charging started. So, the Charge button will resume a stopped charge. However, I just plugged in the car (set to do a timed charge later), hit the Charge button and nothing happened. Hitting the stop button didn't do anything either, the charge port remained in the blue state (meaning it is getting a valid pilot signal from the HPC).

    Now I think those buttons don't do any magic, probably just kill the pilot signal if the car is charging, then turn it back on when Charge is hit.

    So that's more support for the theory that Tesla pilot protocol = J1772 pilot protocol.
     
  17. dsm363

    dsm363 Roadster + Sig Model S

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    I agree. Tesla needs to switch to the J1772 plug to make it easier for people to adopt their car.
    Have current owners called Tesla to ask about the plug/adapter issue? I think if they get a few hundred phone calls, that may help. If owners were willing to pay for maybe part of the conversion process (option 1), maybe that'd make Tesla's decision easier. Of course I don't think people should have to pay more than a few hundred to $1000 for the process.
     
  18. eledille

    eledille TMS 85 owner :)

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    If they standardize on J1772, they will have to provide a different plug for the European market. That might be one reason why they want adapters to their own plug instead of J1772 and IEC 62196 directly. IEC 62196 which will be used in Europe has a different connector and uses single phase up to 16 A and three phase from 16 to 250A. Worse, the Roadster can't handle 3~ at all, so it's limited to 16A with IEC 62196.

    For Model S they have also promised charging at up to 480V 80A 3~. J1772 doesn't support that. How does that fit into the picture?
     
  19. doug

    doug Administrator / Head Moderator

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    #19 doug, Sep 15, 2010
    Last edited: Sep 15, 2010
    I'm not a fan of the Yazaki J1772 connector since I think it's rather limited and short sighted compared to the European IEC 62196 proposal. But that said, it seems it is the de facto (even official) standard on this side of the pond and there is certainly no reason to continue with the Tesla connector if J1772 is just as capable and soon to be ubiquitous.

    I've suggested a compact rigid cylindrical adapter (like Tom's #2) in the past since the signaling is supposed to be compatible and that should work with the relative form factors. I think that's the best temporary solution while new charging stations get installed and perhaps existing public Tesla HPCs get changed over. Eventually there should be a retrofit plan for existing customers if that's what they want.

    As an aside the Mennekes IEC 62196 is also supposed to have compatible signalling, but their model allows (suggests?) users to carry their own cables. So it's easy to have a Mennekes connector on one end and whatever else (Tesla, Yazaki) on the other.

    I've heard murmurs of 3 phase for the Model S before but no promises. The existing Tesla connector doesn't support 3~ either, so if they're really are going to offer it, some kind of change will have to be made. Annoying that the powers that be couldn't just agree on a global standard.
     
  20. RocketMaker10000

    RocketMaker10000 EV Component Retailer

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