New SAE Standard for NACS: Request to Decode

[GMan]

Can anyone distill what, if anything, this means for us?

Will we be able to charge at higher speeds than 50 kW (I thought this was a limit with NACS, due to the Lucid 900v architecture).

SAE's NACS certification is ready, and it’ll fix every EV charging problem at once

SAE has finalized its NACS certification effort, and the new standard promises to fix a *lot* of the current issues with EV charging.

electrek.co

 

[segbrk]

NACS is not what limits Lucids to 50 kW. NACS should be able to support higher voltages. It's the current gen Superchargers (400V) combined with Lucid's Wunderbox. Supposedly, the V4 Superchargers are going to be 1000V - they just don't exist yet. Nothing is going to change for current Airs with current Superchargers, one side or the other needs new hardware.

 

[Tâm]

Will we be able to charge at higher speeds than 50 kW (I thought this was a limit with NACS, due to the Lucid 900v architecture).

Not an expert but this is what I got from social media:

NACS is a standard that includes all voltages from 120V, 240V, 400V, and all the way to 1000V, but it's up to the charger owner to choose what voltage to provide.

Newer cars have 800V charging capability, but hooking to lower voltages requires some voltage-boosting technology from your car, such as boosting your 120V household voltage to 800V for your Lucid.

To boost 400V to 800V, Lucid uses the Wonderbox. The maximum speed for boosting is 50kW speed. That is its specs.

Others, like Mercedes MMA, use a different boosting technology, so it can charge quickly: 350kW at an 800V station and 170kW at a 400V station.

GM Ultium would have 2 separate 400V battery packs. Parallel to charge at 400V station, and serial is to charge at 800V station. Tesla Cybertruck also uses this kind of trick and in real life, it can charge 250kW at a 400V station and 330kW at a 800V station.

Each brand of car chooses its own boosting technology. For Lucid, 50kW speed to boost a 400V station to 800V Lucid architecture is its specs.

It is doubtful that it will change anytime soon.

 

[GMan]

NACS is not what limits Lucids to 50 kW. NACS should be able to support higher voltages. It's the current gen Superchargers (400V) combined with Lucid's Wunderbox. Supposedly, the V4 Superchargers are going to be 1000V - they just don't exist yet. Nothing is going to change for current Airs with current Superchargers, one side or the other needs new hardware.

So when connecting to a 1000v Supercharger, no boost by the Wonderbox would be required and therefore Air's would charge along their present charging curves?

 

[xponents]

So when connecting to a 1000v Supercharger, no boost by the Wonderbox would be required and therefore Air's would charge along their present charging curves?

Yes.

 

[scal_air]

1000v Supercharger .Which will debut first, that or the Roadster?

 

[DeaneG]

I have not heard of any public installation of 1000V capable supercharging power cabinets.

 

[Tâm]

So when connecting to a 1000v Supercharger, no boost by the Wonderbox would be required and therefore Air's would charge along their present charging curves?

You are correct but as others hinted, I would not expect Tesla to install 1000V stations anytime soon.

I expect others like EA, EvGo, Mercedes, GM... will provide their own 1000V NACS well before Tesla will.

 

[EVCar]

You are correct but as others hinted, I would not expect Tesla to install 1000V stations anytime soon.

I expect others like EA, EvGo, Mercedes, GM... will provide their own 1000V NACS well before Tesla will.

Would not be surprising to me if this is true. But somehow I suspect Tesla will be among the first to get federal grant money.

 

[Adnillien]

Would not be surprising to me if this is true. But somehow I suspect Tesla will be among the first to get federal grant money.

Tesla paid some lobbyist to get a recent interpretation on the NEVI rules that funds any charger capable of putting out any single voltage between 250V and 920V not all voltages between 250V and 920V. Under this interpretation, a charger that supplied 260V, that would not even charge a Tesla, could receive NEVI funding. I agree that Tesla will be one of the first to receive funding, but they will not be 1000V chargers which was intended by the NEVI rule making.

 

[Tâm]

Would not be surprising to me if this is true. But somehow I suspect Tesla will be among the first to get federal grant money.

On 4/2/2024, Tesla already unveiled its first NEVI-funded 400V V4 Tesla Supercharger in Maine:

A Tesla Supercharger is Maine's first NEVI EV charging station

Maine just opened its first NEVI Formula Program-funded EV charging station – a Tesla Supercharger with CCS compatibility.

electrek.co

 

[scal_air]

Help an electrical engineer never been out here... 250kW charger = 400V?

 

[xponents]

Help an electrical engineer never been out here... 250kW charger = 400V?

Nope. For example, a 800v charger can also run at 3 kWh if it wanted to! It’s easier to obtain 350 kWh with 800v, but it’s theoretically possible with 400v too. Nobody does it as that would be inefficient and the system would be pushed hard. In the case of superchargers, yes, 400v equals 250kwh. I do think @Adnillien could answer this far clearer and more detailed than me, so I’ll leave it at that.

 

[Tâm]

Help an electrical engineer never been out here... 250kW charger = 400V?

Google is my friend:

Ohms Law Calculator

This free Ohm's Law calculator solves for any of the variables in the Ohm's Law equation using various units of measurement and gives out the solving steps.

www.calculator.net

Enter into the calculator:

400v x 625A resulting 250,000W or 250kW

 

[scal_air]

Google is my friend:

Ohms Law Calculator

This free Ohm's Law calculator solves for any of the variables in the Ohm's Law equation using various units of measurement and gives out the solving steps.

www.calculator.net

Enter into the calculator:

400v x 625A resulting 250,000W or 250kW

Thank you....Where did the 625A come from?

 

[Electrified]

Help an electrical engineer never been out here... 250kW charger = 400V?

250 kW is 250 kW, the only differences are the wire gets bigger as the voltage goes down, and the wire gets smaller as the voltage goes up.
Ohm's Law

 

[scal_air]

Thank you....Where did the 625A come from?

Sorry looking at the website... but then where did the resistance (0.64 ohms) come from the calculate the amperage?

 

[Tâm]

Thank you....Where did the 625A come from?

I can either make up that Ampere number in order to get the answer of 250kW or I can pick any numbers on the Charger label:

AC Input
Voltage Range: 528V
Max Continuous Current: 465A

Enter into the calculator:

528v x 465A resulting 245,520W or 245.5 kW or round it up to 250kW to match the advertisement.

Ohms Law Calculator

This free Ohm's Law calculator solves for any of the variables in the Ohm's Law equation using various units of measurement and gives out the solving steps.

www.calculator.net

The power utility company has to supply these minimum numbers, including the Amperes, in order for the charger to achieve the results.

 

[Tâm]

Sorry looking at the website... but then where did the resistance (0.64 ohms) come from the calculate the amperage?

The resistance didn't come from me. I only enter V and Ampere, then the calculator does the rest.

I don't know what the Ampere number is. I just randomly picked one, then increase or decrease it until I got the 250kW answer.

I got the answers from the web. The right way should be from traditional schooling but I have no patience for a classroom in my old age.