-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
Tesla Model S UMC cut open and modified to J1772
- Thread starter TonyWilliams
- Start date
-
- Tags
- Technical
Have you ever needed a little extra cord to plug in your car? Has the charging spot ever been blocked, either by an ICE or an EV that had already finished charging? Now, you can get a J1772 extension cord to help you plug in!!!
Introducing JLongtm, the J1772 extension cord solution. The cord and plug assembly is UL Rated up to 30A and 240V AC, however I have used these at 40 amps without excessive heat buildup.
The cord is 20 feet long.
$299 complete, plus shipping and handling fee of $35 for USA and Canada, $334 total.
One year limited warranty.
I will waive the individual $35 shipping fee if you buy this at the same time as a JESLAtm, the 40 amp J1772 portable charging solution.
[email protected]
Quick Charge Power
Last edited:
Ron95030
Member
Tony, the schematic symbol for S3 is wrong. You have a normally open symbol, but since it's normally closed and the depression of the switch adds 330 ohms to the circuit; you should place the 'bar' to the right of the two black dots (closer to R7).
How's that for pickiness!
Sorry!
-Ron (the nerd) up north!
How's that for pickiness!
Sorry!-Ron (the nerd) up north!
I just wanted to publicly thank TonyWilliams for his good work.
I have been a proud owner of what he now calls the Jesla portable charging station since this summer but have only been able to use it for the first time this evening. A Telsa Roadster Owner had a NEMA 14-50 plug installed in the garage across the street from my apartment building and it showed up on PlugShare yesterday when I checked on a whim. I purchased Tony's solution with the intent of installing a NEMA 14-50 outlet in my garage at work, but I am still unable to get the management of the garage to agree to install same.
In any case, a NEMA 14-50 is much cheaper to install than the rip off EVSEs that sucked up all the government grants and since most EV drivers carry the necessary charging cables, I believe this "BYO charging cable" sceme is the best, or at least most economical, way to expand public charging solutions.
Thank you again TonyWilliams.
I have been a proud owner of what he now calls the Jesla portable charging station since this summer but have only been able to use it for the first time this evening. A Telsa Roadster Owner had a NEMA 14-50 plug installed in the garage across the street from my apartment building and it showed up on PlugShare yesterday when I checked on a whim. I purchased Tony's solution with the intent of installing a NEMA 14-50 outlet in my garage at work, but I am still unable to get the management of the garage to agree to install same.
In any case, a NEMA 14-50 is much cheaper to install than the rip off EVSEs that sucked up all the government grants and since most EV drivers carry the necessary charging cables, I believe this "BYO charging cable" sceme is the best, or at least most economical, way to expand public charging solutions.
Thank you again TonyWilliams.
You're welcome. It's been fun.
Yes, I agree, a whole bunch of NEMA 14-50's can be put in very cheap.
All products from Quick Charge Power, including the JESLA 40 amp J1772 portable charging solution based on the Tesla UMC, now have a one year limited warranty, retroactive to every product sold previously.
Thanks to all who have supported us, and now we can support you even better.
Thanks to all who have supported us, and now we can support you even better.
I have a question about the JESLA. I am looking for a portable EVSE that can be used to charge my non-Tesla EV in a variety of oddball situations, typically RV parks, and of course the JESLA is designed for that. But I would like to have control over the current that the car is pulling, meaning have the EVSE change the pilot signal to advertise lower current available.
As I understand it, the Tesla UMC reads which plug adapter (14-50, 10-30, etc.) is connected and adjusts the pilot accordingly. Is there any way to manually force the pilot (offered current) DOWN further, below what the UMC thinks the circuit capacity is?
Typical usage scenarios would be:
- hotel parking lot, plugging into 120V outlet on unknown circuit, want to pull low amperage like 5-8 Amps
- RV park, plugging into NEMA 14-50 receptacle *BUT* pull just 30 Amps due to flaky breaker
The Tesla cars take care of this by manual override IN THE CAR of how much current is pulled. You set a max current, and so can back down from what the EVSE might be offering.
But most other cars don't have this capability, so you rely on the EVSE to do it.
I don't think the JESLA can do this, so have been looking into JuiceBox and OpenEVSE, but I thought I'd ask to make sure.
As I understand it, the Tesla UMC reads which plug adapter (14-50, 10-30, etc.) is connected and adjusts the pilot accordingly. Is there any way to manually force the pilot (offered current) DOWN further, below what the UMC thinks the circuit capacity is?
Typical usage scenarios would be:
- hotel parking lot, plugging into 120V outlet on unknown circuit, want to pull low amperage like 5-8 Amps
- RV park, plugging into NEMA 14-50 receptacle *BUT* pull just 30 Amps due to flaky breaker
The Tesla cars take care of this by manual override IN THE CAR of how much current is pulled. You set a max current, and so can back down from what the EVSE might be offering.
But most other cars don't have this capability, so you rely on the EVSE to do it.
I don't think the JESLA can do this, so have been looking into JuiceBox and OpenEVSE, but I thought I'd ask to make sure.
If you have an EV only capable of charging at 30 amps (like the Focus Electric), you don't need the UMC to tell the car to only pull 30 amps as that is all it can pull. For the 120V circuit, you cant adjust the limit below 12 amps on the UMC, unfortunately. This is set by the resistance within the adapter that is plugged in.
You could add a rotary switch so you could manually choose exactly which pilot resistances you want at any given situation. You could have more choices than currently offered (pun intended). And disable the auto-choosing scheme. Only for them that knows what they are doing, of course.
--
--
Just wanted to say that the JESLA has been great for my situation. I have a one car garage with a 14-50 outlet. My wife drives the Model S and I drive the Leaf. Instead of installing a fixed J1772 station, using the JESLA for the Leaf and then continuing to use the Tesla UMC for the Model S has been great! I have both charging adaptors hanging from the garage wall and all I need to do is unplug one and plug in the other so I can charge both cars with their respective adapters.
Prior to this I was just charging the Leaf with the 110v portable charger they supplied and there were days where it was quite challenging to work out the charging schedule at home! I know I could have bought a J1772 station and used it with both cars, but I was waiting for a simpler and smaller solution and the JESLA has worked out perfectly, thanks for creating it!
Prior to this I was just charging the Leaf with the 110v portable charger they supplied and there were days where it was quite challenging to work out the charging schedule at home! I know I could have bought a J1772 station and used it with both cars, but I was waiting for a simpler and smaller solution and the JESLA has worked out perfectly, thanks for creating it!
Thanks everybody for the kind words. While this was conceived as something for the Tesla powered Rav4 EV, I won't be surprised if virtually every type of J1772 equipped car is using a JESLA somewhere.
As to the adjustability of the pilot signal, I don't know, but I intend to find out !!! If we can change the pilot signal with a simple switch, we will.
As to the adjustability of the pilot signal, I don't know, but I intend to find out !!! If we can change the pilot signal with a simple switch, we will.
Not sure if you mean that you plug/unplug the NEMA 14-50, or the proprietary connector between the 14-50 adapter and the UMC. But beware, these things can wear out. Certainly a NEMA 14-50 outlet is not designed for repeated plug/unplug cycles, and the connections will eventually loosen, which has to the potential to start a fire. I image the proprietary adapter connection is designed to handle this, but I'm not sure. Certainly the connection on the car side is designed the handle repeated plug/unplug cycles, as is the J1772 adapter.
My suggestion is to leave the JESLA plugged into the wall, and use the J1772 adapter to charge the Telsa, and and then remove the adapter to charge the Leaf.
You might have to replace a lot more than that if it catches fire. The new 14-50 adapter with the thermal fuse should mitigate the risk, somewhat, but I'd still be cautious.
Thanks, I'll monitor this thread for the results.
To be clear on what is desired, we would like to adjust that pilot down to advertise LESS than the typical current. The ideal is what Tesla implements in their cars, which is 1 Amp granularity all the way down to 5 Amps. Assuming you can't offer that kind of control, then some sort of multiposition switch would be the next step down, so that you could offer the most popular currents (e.g. full, 30A, 12A, 6A). For me that would have to include 5-8 Amps on a 120 V circuit, and 30-35 Amps on a 240 circuit, both for purposes of avoiding a breaker trip on a circuit that simply can not offer the full current for whatever reason.
If you could only offer a simple binary "switch flip" control, then I suppose good logic would be to have it switch between "nominal" mode (100% of nominal current, with pilot based on usual UMC logic) and "degraded" mode (say 75% of nominal, based on same logic). That would then neatly handle most cases, especially the RV park with a NEMA 14-50 that trips at anything above 35 Amps.
All that said, I can see how it would be difficult to do this. Unlike the simpler resistor/diode mods that you are already doing, this would involve decoding the pilot duty cycle coming out of Tesla's UMC logic, and then reencoding it at a lower duty cycle. I suppose there may be a simple analog way of doing that, but to do so digitally would certainly be complicated.
Last edited:
Thanks for the good advice. I have been switching the plug where it goes into the outlet. It's not that often though. I'd day on a monthly basis I end up doing the switch about 10 times. I could just leave the Tesla 14-50 adapter plugged in and just disconnect the JESLA and UMC end to save the wear on the outlet itself. I've considered using the J1772 adapter to charge the Model S and then removing it to charge the Leaf (that was actually what my original plan was but I found that it's convenient to have the switch on the Tesla connector to open the port cover).
I'll keep an eye on the outlet and change it out if it appears to show signs of wear. The real test will be when the BMW i3 arrives at our home in June plus the combination of having my office commute go from 7 total miles to 25 total miles a day. If I find I'm having to charge more frequently with the i3, I'll probably just go with the J1772 adapter solution.
We just had our first failure of a JESLA in the field, and of course, I wanted to know what failed before I made the warranty exchange.
We popped on the NEMA 5-15 Tesla plug on the JESLA / UMC. We did have 3.3 volts at the JESLA's plug end LED light (that is power for the charge port opener on a Tesla Model S plug that we remove for the J1772 plug), and we had 12 volts at the pilot pin in "State A" (normal and proper). The proximity pin properly had 150 ohms static and 480 ohms when the disconnect button was pushed.
So, we applied 2.7k ohms resistance to the pilot signal and nothing happened. The error LED was on the UMC flashed red. By some miracle, we guessed that the UMC did a diode check, so one diode was installed in series with the 2.7k resistor. It worked, as the error LED was now green and we measured 8.8 volts DC on the Fluke multimeter from the pilot pin. We should have had "State B", so we hooked up the oscilloscope to observe the appropriate 1kHz square wave at a 20% duty cycle, proper for 12 amps.
Then, we applied 880 ohms resistance to the pilot signal and moved to "State C", we heard the relay contactor close in the UMC, and the green LED was sequencing to indicate it was "charging". We measured 120 volts across the two power pins in the J1772 plug.
So, everything works, which led us to believe that the car (the owner used this to charge a Rav4 EV) had a faulty diode on his car. But, more testing.
We put the NEMA 14-50 Tesla plug on it. When we plugged it in the 240 volt supply power, the UMC flashed red eight times, which according the UMC owner's manual for "more than 6 flashes" is "the Mobile Connector may need repair" and "contact Tesla Service". So, no help.
Then, we tried a "known-good" NEMA 14-50 Tesla plug and everything worked normal again. Voila, the problem had been isolated to the NEMA 14-50 Tesla plug. Since these are a known issue, we put an ohmmeter across every pin/blade and socket of the NEMA 14-50. One of the power pins was open to its appropriate socket. We found the specific problem.
But, this brings up an interesting feature of the UMC. Was this failing because it only saw 120 volts total (instead of 120 volts on each power pin for 240 volts total) and the UMC knew it should be 240 volts, or was it faulting because the polarity was wrong (the wrong pin showing 120 volts)? I suspect the latter, because we already know that the UMC is polarity sensitive. Obviously, the supply power circuit wasn't complete for either 120 volts or 240 volts with the open power pin.
This would have been a good time to test for the sensitivity for pilot signal duty cycle (varying the pilot signal from 6 amps to 40 amps with nothing more than a resistor), but we ate lunch instead.
I went to the Tesla Service Center and, of course, they had none of the NEMA 14-50 Tesla plugs in stock, nor were there any UMC's to be purchased. So, it's just broken until Tesla gets the parts...
or, should I cut it open and see WHY it failed and can I fix it? Let me know.
Reference: https://code.google.com/p/open-evse/wiki/J1772Basics
We popped on the NEMA 5-15 Tesla plug on the JESLA / UMC. We did have 3.3 volts at the JESLA's plug end LED light (that is power for the charge port opener on a Tesla Model S plug that we remove for the J1772 plug), and we had 12 volts at the pilot pin in "State A" (normal and proper). The proximity pin properly had 150 ohms static and 480 ohms when the disconnect button was pushed.
So, we applied 2.7k ohms resistance to the pilot signal and nothing happened. The error LED was on the UMC flashed red. By some miracle, we guessed that the UMC did a diode check, so one diode was installed in series with the 2.7k resistor. It worked, as the error LED was now green and we measured 8.8 volts DC on the Fluke multimeter from the pilot pin. We should have had "State B", so we hooked up the oscilloscope to observe the appropriate 1kHz square wave at a 20% duty cycle, proper for 12 amps.
Then, we applied 880 ohms resistance to the pilot signal and moved to "State C", we heard the relay contactor close in the UMC, and the green LED was sequencing to indicate it was "charging". We measured 120 volts across the two power pins in the J1772 plug.
So, everything works, which led us to believe that the car (the owner used this to charge a Rav4 EV) had a faulty diode on his car. But, more testing.
We put the NEMA 14-50 Tesla plug on it. When we plugged it in the 240 volt supply power, the UMC flashed red eight times, which according the UMC owner's manual for "more than 6 flashes" is "the Mobile Connector may need repair" and "contact Tesla Service". So, no help.
Then, we tried a "known-good" NEMA 14-50 Tesla plug and everything worked normal again. Voila, the problem had been isolated to the NEMA 14-50 Tesla plug. Since these are a known issue, we put an ohmmeter across every pin/blade and socket of the NEMA 14-50. One of the power pins was open to its appropriate socket. We found the specific problem.
But, this brings up an interesting feature of the UMC. Was this failing because it only saw 120 volts total (instead of 120 volts on each power pin for 240 volts total) and the UMC knew it should be 240 volts, or was it faulting because the polarity was wrong (the wrong pin showing 120 volts)? I suspect the latter, because we already know that the UMC is polarity sensitive. Obviously, the supply power circuit wasn't complete for either 120 volts or 240 volts with the open power pin.
This would have been a good time to test for the sensitivity for pilot signal duty cycle (varying the pilot signal from 6 amps to 40 amps with nothing more than a resistor), but we ate lunch instead.
I went to the Tesla Service Center and, of course, they had none of the NEMA 14-50 Tesla plugs in stock, nor were there any UMC's to be purchased. So, it's just broken until Tesla gets the parts...
or, should I cut it open and see WHY it failed and can I fix it? Let me know.
Reference: https://code.google.com/p/open-evse/wiki/J1772Basics
Last edited:
Similar threads
- Article
