CCS Adapter for North America

[Eno Deb]

It is necessary.

I have to check the spec again, but the DC pins protrude more than the other pins to allow the car and/or charger to detect that the plug is being disconnected before the DC lines are disconnected. But sure, arcing is more of a risk at 400 or 800V than 240.

It is being done on the Tesla CCS type 2 adapter mechanically as the lock is the same on the car port as it is a modified type 2. All that is needed is a mechanical lever inside the adapter.
The locks are not the same on the TSL-02 port in the US and the CCS type 1 so a separate electromechanical lock needs to be implemented on such adapter, something will have to drive that lock, it will be big, and it will be a failure point. Hence having a CCS type 1 adapter is not as straight-forward.

I still don't understand why that would be necessary. AFAIK type 1 CCS plugs are designed such that the release latch can be locked by the charger. So, the Tesla adapter would be locked into the port by the car (just like the J1772 adpater), and the plug would be locked to the adapter by the charger. Why would there be an additional locking mechanism on the adapter? AFAIK cars with native CCS type 1 ports don't have a locking mechanism in the inlet either.

 

[Fredneck]

Can you point out somewhere you see this happening? I haven't seen that yet. Where I keep watching the EA deployment, they are simply re-treading the same ground and the same interstate routes that Tesla covered years ago. That makes sense anyway I guess, since those are obviously the most popular routes. But I haven't seen EA cover routes that Tesla doesn't have. Of course that is different than having extra capacity in some places, where the Supercharger is usually full and the EA station a few miles away is mostly empty.

It doesn't have to be routes. If Tesla has a gap along a route it can be faster to charge at an EA charger if you can drive further without stopping. That happens along Rt 81 in numerous places. I've driven Rt 81 many times and I never get to use anything close to my full range on the whole trip. I should be able to stop once in the middle of a 500 mile trip, but I can't because there's no charger in the right spot.

 

[Fredneck]

I have to check the spec again, but the DC pins protrude more than the other pins to allow the car and/or charger to detect that the plug is being disconnected before the DC lines are disconnected. But sure, arcing is more of a risk at 400 or 800V than 240.

That's a fail-safe backup feature. The power is cut before the lock is released, so where is the flash risk?

 

[Eno Deb]

That's a fail-safe backup feature. The power is cut before the lock is released, so where is the flash risk?

The question seems to be whether a locking mechanism is mandatory for DC charging (it isn't for L2 AC charging).

 

[Can37]

The question seems to be whether a locking mechanism is mandatory for DC charging (it isn't for L2 AC charging).

I don't think it is mandatory, you can unplug a DCFC charger on my e-Golf while it is charging. Pressing the latch on the handle cuts the power allowing safe removal. Oddly, on the e-Golf, the L2 connector does lock and you have to manually unlock the car, which stops the charging by opening the pilot contact and then you can remove the connector. Locking or unlocking the car does not shutdown the DCFC.

 

[vdiv]

There are significant differences between AC charging and DC charging that necessitate different precautions and implementations of power interfaces. One needs to understand the difference between AC and DC, the difference in voltage and current values, the difference between voltage and current sources, the difference in transients, capacitance, arcing and factors affecting it, etc.

Need to also understand the specifics and differences among the various standards, which would then make the challenges of adapting them clear. In addition to those challenges there are regulatory and business considerations that Tesla has in determining whether a CCS type 1 adapter is feasible and will be made. We just hope they are more upfront with where they stand.

 

[Fredneck]

The question seems to be whether a locking mechanism is mandatory for DC charging (it isn't for L2 AC charging).

A lock is part of the J1772 spec for level 2 charging. I have no idea if it is mandatory for DC charging, but it is part of the Tesla design. I'm not clear on what the question is about. Who would make it "mandatory"? Are we talking about a standards organization, or a government thing, or what?

 

[Eno Deb]

A lock is part of the J1772 spec for level 2 charging. I have no idea if it is mandatory for DC charging, but it is part of the Tesla design.

The Tesla J1772 adapter does not lock the charger plug (only the adapter is locked to the car).

I'm not clear on what the question is about. Who would make it "mandatory"? Are we talking about a standards organization, or a government thing, or what?

The CCS standard (maintained by CharIN).

 

[Saghost]

A lock is part of the J1772 spec for level 2 charging. I have no idea if it is mandatory for DC charging, but it is part of the Tesla design. I'm not clear on what the question is about. Who would make it "mandatory"? Are we talking about a standards organization, or a government thing, or what?

Some J1772 cars lock the cable, some don’t. My Volt didn’t, and I don’t think any GM EVs do for J1772.

Of course, there’s a lot more risk with an unplanned disconnect of 400V DC, so locking DCFC is the norm (I don’t know if the standards require that or not.)

 

[Fredneck]

The Tesla J1772 adapter does not lock the charger plug (only the adapter is locked to the car).
The CCS standard (maintained by CharIN).

I'm not talking about a lock in the sense of anti-theft. I should have said a "latch".

Maybe we are drifting topic a bit. I thought we were discussing safety issues, such as cutting power before the connector is disengaged. Are we talking about an actual lock that prevents removal?

 

[Fredneck]

Some J1772 cars lock the cable, some don’t. My Volt didn’t, and I don’t think any GM EVs do for J1772.

Of course, there’s a lot more risk with an unplanned disconnect of 400V DC, so locking DCFC is the norm (I don’t know if the standards require that or not.)

That's what I don't get. Where is the risk? Before the J1772 connector can be removed it has to be unlatched. Unlatching cuts power before you can remove the connector. Why would the connector need to be "locked" to the car rather than just latched?

 

[Daniel in SD]

That's what I don't get. Where is the risk? Before the J1772 connector can be removed it has to be unlatched. Unlatching cuts power before you can remove the connector. Why would the connector need to be "locked" to the car rather than just latched?

It's easy to remove a J1772 connector before it cuts power. It creates an arc which can eat away at the contacts.
DC power creates a more sustained arc than AC since it's not cycling on and off (it takes less current to maintain an arc than to start one). This is why relays and switches have lower ratings for DC vs. AC.

 

[Fredneck]

It's easy to remove a J1772 connector before it cuts power. It creates an arc which can eat away at the contacts.
DC power creates a more sustained arc than AC since it's not cycling on and off (it takes less current to maintain an arc than to start one). This is why relays and switches have lower ratings for DC vs. AC.

Please explain to me how you do that? The J1772 connector has a latch button which when pressed cuts the power. Is your connector broken so the latch doesn't hold?

 

[MP3Mike]

Please explain to me how you do that? The J1772 connector has a latch button which when pressed cuts the power. Is your connector broken so the latch doesn't hold?

People have reported encountering J1772 handles where the electric portion of the latch button no longer works, but it still physically unlatches the connector. You can't ever have that happen when DC fast charging.

 

[AlanSubie4Life]

Please explain to me how you do that? The J1772 connector has a latch button which when pressed cuts the power. Is your connector broken so the latch doesn't hold?

I am not talking about DC charging here, but just speaking to AC charging: I assure you that if you are fast enough you can unlatch a completely functional J1772 and remove it from the port before the current is stopped. I've generated a mild orange arc (probably about 4-8 inches long) this way myself (on a 208V 30A charging station). It usually results in the red Tesla T followed by a required manual release of the adapter, and various dire messages on the in-car display. I always press the button now and wait a second before removing. Took seeing the arc (required low light conditions) for me to realize why I was getting the red Tesla T on the charging port occasionally.

There is also the case of broken buttons (which do not prevent charging). In those cases it's best to disable the charging from the app, the charging station, or the car, before removing.

 

[Fredneck]

People have reported encountering J1772 handles where the electric portion of the latch button no longer works, but it still physically unlatches the connector. You can't ever have that happen when DC fast charging.

That's why the pins are a different length so the pilot disconnects first acting as a backup safety shutdown preventing arcing. So how did the arcing happen with the J1772 connector?

Why can't a DC connector fail?

 

[AlanSubie4Life]

So how did the arcing happen with the J1772 connector?

This is a pretty easy thing to reproduce. Just get that current flowing and then very quickly push the button and yank out that J1772. I don't guarantee it will happen every time but it definitely can happen. To help the experiment, park far enough away from the station so that the cable is tugging on the adapter very slightly. That way you'll get a bit of an assist with your yanking of the J1772. Relays take time to open I guess.

I've seen it myself, so I believe it...but I understand that sometimes it takes seeing to believe it.

 

[Saghost]

That's why the pins are a different length so the pilot disconnects first acting as a backup safety shutdown preventing arcing. So how did the arcing happen with the J1772 connector?

Why can't a DC connector fail?

I’m pretty sure the second part there was “it’s important that this never be permitted to happen on a DC connector” rather than “DC connectors don’t do this.”

 

[Fredneck]

I am not talking about DC charging here, but just speaking to AC charging: I assure you that if you are fast enough you can unlatch a completely functional J1772 and remove it from the port before the current is stopped. I've generated a mild orange arc (probably about 4-8 inches long) this way myself (on a 208V 30A charging station). It usually results in the red Tesla T followed by a required manual release of the adapter, and various dire messages on the in-car display. I always press the button now and wait a second before removing. Took seeing the arc (required low light conditions) for me to realize why I was getting the red Tesla T on the charging port.

There is also the case of broken buttons (which do not prevent charging). In those cases it's best to disable the charging from the app, the charging station, or the car, before removing.

I don't recall the protocol off the top of my head, but I'm pretty sure the button is only read by the EVSE which then alters the pilot signal to inform the car to stop drawing power. The pilot signal is a 1 kHz square wave which should be detected by the car within a few milliseconds. If you can pull the J1772 plug out faster than the car shuts down power, the car has a problem.

Then again, the button might be read directly by the car. I seem to recall that button shorts a resistor in a divider that the car can directly sense to detect the connection/button push. Again, if you can cause this problem the car likely has a fault and should be fixed. I'll look at the spec, but either way the arcing should never happen unless there are multiple faults.

 

[AlanSubie4Life]

Then again, the button might be read directly by the car. I seem to recall that button shorts a resistor in a divider that the car can directly sense to detect the connection/button push. Again, if you can cause this problem the car likely has a fault and should be fixed. I'll look at the spec, but either way the arcing should never happen unless there are multiple faults.

I think this is correct from what I recall. I can't remember whether the resistor to ground is in circuit when the button is pressed or the other way around but it doesn't matter for this discussion.

I'm not going to argue that there is no way to make it fast enough, but I'm not the only one who has had this problem, so I'm pretty sure all Model 3s behave the same way. It's a very easy experiment to try, though of course it might take a few attempts - it may well work as designed most of the time.