SAE is standardizing NACS this year – making it less dependent on Tesla

[ohseedee]

Has everybody seen that Polestar and EA have announced support for NACS today as well?

https://media.polestar.com/global/e...o-enable-access-to-tesla-supercharger-network

https://media.electrifyamerica.com/en-us/releases/223

With this EA announcement I'm betting there is a VW announcement coming within the next several weeks...

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[CharonPDX]

Communications still happen on the J1772 side of the port for CCS. There are isolation tests and such that depend on the DC side being connected, but if it starts those, it's going to blow up your OBC. This is why CCS1 is better engineered than NACS, because there is no chance of this happening with CCS1 alone.

The "DC side" of the "NACS" connector is the exact same as the AC side of a J1772 port. Destination adapters connect them together and they are dumb. The PLC signals likely will still pass through on them but I definitely haven't tested it.

Yes, communications happen over the 3 data pins of the J1772 side of the port - but it is a different protocol. J1772 is a simple "is there resistance of a certain value over the pins? Yes, what is that resistance? Okay, now I know how much power is available." That's it. And a simple continuity check over another pin. Press the handle, it breaks continuity, and the EVSE stops providing power over the high-power pins.

CCS is an actual bidirectional data flow - it just happens to be over the same pins.

NACS will be similar - as the Tesla connector from its conception is similar - different data "protocol" depending on AC or DC. With some slight logic to identify which is which before it even thinks about flowing any power through the power pins. Tesla just uses a different DC communication protocol historically than NACS will use.

 

[MP3Mike]

Tesla had issues with certain CCS chargers blowing up their OBCs because the chargers were providing the maximum voltage they could produce during the initial testing instead of what the Tesla vehicles were rated to. They had to make engineering changes to increase their withstand voltage. Shit definitely wouldn't have happened if they didn't share the pins between AC and DC.

Do you have any reference to what they had to change or what vehicles it impacts? I have never heard of that. (And it doesn't seem to be supported by existing Teslas being able to be retrofitted to support CCS with just an adapter and a charge controller update to enable PLC communication.) That actually sounds more like a CCS charger not following standards and the CCS hardware vendor probably had to update their chargers.

Or are you saying that there are a whole raft of Tesla vehicles out there that have to have their OBC replaced to be able to use CCS chargers?

 

[Dark-Fx]

Or are you saying that there are a whole raft of Tesla vehicles out there that have to have their OBC replaced to be able to use CCS chargers?

I'm trying to find the article on it. First read about it a couple years ago when the CCS1 -> Tesla adapters were first coming out. I think Tesla was able to fix the issue with other changes to their system.

Obviously the CCS stations are doing something they aren't supposed to but that shouldn't surprise anyone. I don't think Tesla ever expected to need the capability to withstand more than what their own chargers will provide.

 

[atebit]

I guess we will have Level 1, Level 2, and Level 3 NACS? Hopefully they put a stronger team on this one and, seriously, someone buy those guys a thesaurus. Even better, hire them an English major. They are inexpensive.

Coming soon…”EV Charging 6”!

Goes nicely with “Web 2.0” and “Industry 4.0”.

 

[Nix]

What happens if there is a disagreement between the two? Will we end up with even more fragmentation?

That's exactly what would happen. Worst case scenario is CCS, NACS owned by SAE, and a new Tesla Not-A-NACS charging standard.

Not a great future, but at least there would be a choice between the clunky CCS connector and an NACS plug for non-Tesla owners.

The elephant in the room is that eventually even faster charging rates will out-grow all the current known standards, and there will be NACS 2.0, or Super NACS, or NACS 6G or whatever they come up with.

 

[Nix]

Please allow me to introduce you to my friend USB:
...

Which one would I use to upload a virus from a Mac to an alien mothership?

 

[RWerksman]

Looks to be an update:

SAE wants to certify NACS by end of year, and fix plug & charge too
https://electrek.co/2023/07/12/sae-wants-to-certify-nacs-by-end-of-year-and-fix-plug-charge-too/

The Society of Automotive Engineers (SAE) has voted unanimously to form a task force to expedite its North American Charging Standard (NACS) standardization process and thinks that this process could finish by the end of the year – much earlier than expected.

The NACS connector already exists on millions of vehicles and makes up the majority of the installed base in the US. Since their stations are listed to UL standards and have been proven in the real world, many questions are already answered. The standard will likely take the official name “J3400,” similar to the name of the current J1772 plug used in SAE CCS chargers.

Additionally, two additional items from the article that I found particularly interesting:

• NACS is superior to J1772 for AC charging in one significant way – it can use an input voltage of up to 277 volts, whereas J1772 uses 208-240V. This not only enables faster AC charging due to higher voltages but more importantly makes for easier setup on commercial electricity supplies, which is often supplied as 480-volt three-phase power, of which a 277-volt single-phase circuit can be used for charging. This could make public AC charging – in parking garages for apartment buildings or workplaces, for example – cheaper and easier to install since commercial customers won’t need to install their transformers.
• Tesla has been very helpful with the process in the last two weeks since SAE proposed making NACS a real standard and is leaving the future of NACS up to a consensus-based standards process.

 

[Dark-Fx]

Looks to be an update:

SAE wants to certify NACS by end of year, and fix plug & charge too
https://electrek.co/2023/07/12/sae-wants-to-certify-nacs-by-end-of-year-and-fix-plug-charge-too/

The Society of Automotive Engineers (SAE) has voted unanimously to form a task force to expedite its North American Charging Standard (NACS) standardization process and thinks that this process could finish by the end of the year – much earlier than expected.

The NACS connector already exists on millions of vehicles and makes up the majority of the installed base in the US. Since their stations are listed to UL standards and have been proven in the real world, many questions are already answered. The standard will likely take the official name “J3400,” similar to the name of the current J1772 plug used in SAE CCS chargers.

Additionally, two additional items from the article that I found particularly interesting:

• NACS is superior to J1772 for AC charging in one significant way – it can use an input voltage of up to 277 volts, whereas J1772 uses 208-240V. This not only enables faster AC charging due to higher voltages but more importantly makes for easier setup on commercial electricity supplies, which is often supplied as 480-volt three-phase power, of which a 277-volt single-phase circuit can be used for charging. This could make public AC charging – in parking garages for apartment buildings or workplaces, for example – cheaper and easier to install since commercial customers won’t need to install their transformers.
• Tesla has been very helpful with the process in the last two weeks since SAE proposed making NACS a real standard and is leaving the future of NACS up to a consensus-based standards process.

The second part is reassuring. I still want the SAE to address the lack of fail-safe protection for the DC charging contactors.

 

[MP3Mike]

I still want the SAE to address the lack of fail-safe protection for the DC charging contactors.

Address it how? They can't change the standard that would result in it being incompatible with the existing vehicles on the road.

Tesla has already addressed this in their standards documents: https://tesla-cdn.thron.com/static/...tandard_AC_DC_Pin_Sharing_Appendix_O3AG95.pdf

 

[Dark-Fx]

Address it how? They can't change the standard that would result in it being incompatible with the existing vehicles on the road.

Tesla has already addressed this in their standards documents: https://tesla-cdn.thron.com/static/...tandard_AC_DC_Pin_Sharing_Appendix_O3AG95.pdf

Stranding the user from a single electromechanical in the charging circuit failure is not OK in my book.

 

[Longreach]

Stranding the user from a single electromechanical in the charging circuit failure is not OK in my book.

Give it up, Dark-Fx, it’s over.

Enjoy your new high reliability charging options!

 

[Dark-Fx]

Give it up, Dark-Fx, it’s over.

Enjoy your new high reliability charging options!

Been enjoying RAN, thank you.

 

[MP3Mike]

Stranding the user from a single electromechanical in the charging circuit failure is not OK in my book.

So, what happens in a CCS EV when one of the fast charge contactors fails and welds shut? That leaves HV DC exposed on the charge port, if the main contactors are closed does it not? Doesn't that single electromechanical failure result in having to disable to vehicle to maintain safety?

Maybe I'm missing something, but the failure modes don't seem too different between the two designs.

 

[Dark-Fx]

So, what happens in a CCS EV when one of the fast charge contactors fails and welds shut? That leaves HV DC exposed on the charge port, if the main contactors are closed does it not? Doesn't that single electromechanical failure result in having to disable to vehicle to maintain safety?

Maybe I'm missing something, but the failure modes don't seem too different between the two designs.

The other half of the port is still isolated. And the ports the AC charger use aren't dangerous because there is never a physical attachment to the DC pins.

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