SAE to standardize NACS

[threeputts]

Drive in subzero weather in Minnesota (or the Dakotas.) It’s not hyperbole.

You can recover a bit of that by bringing tire pressure back up to spec, they are inevitably low when it gets very cold.

 

[Tronguy]

Drive in subzero weather in Minnesota (or the Dakotas.) It’s not hyperbole.

Example - I can drive to our cabin using almost exactly 50% charge during the summer. Last winter we left with 95% and had to turn around and double back to a charger because we wouldn’t have made it. (It was -5º F/-20º C out at the time)

Ahem. OK, New Jersey and the Northeast isn't Minnesota, but:

We got two cars over here. A 2018 M3 LR RWD with no heat pump. A 2021 MY LR with one.

When temperatures get well below freezing the M3's W-hr/mile goes from around 225-250 (summer) to 350+. If one drives long enough (we're talking 75-100 mile) the W-hr/mile might drop down to the low 300's on that car, presumably as things warm up somewhat. Short distances might see the W-hr/mile hit nearly 400. And that fits nicely with the 50% drop in range you're reporting. (All of that with using the seat heaters, which allows the cabin temperature to be in the mid-60's, Fahrenheit, comfortably.

The MY is a different story. It's got the heat pump. Weirdly enough, summer W-hr/mile is in the 250 W-hr/mile, not much different than the M3.

Wintertime: Say it's 20F outside. Initial W-hr/mile hits around 320 or so, but swiftly drops to 280 or thereabouts and stays there. So, yeah, there's a hit in cold weather, but it's nowhere near what the M3 is seeing. And not a whole lot different than what an ICE would see although, with an ICE, the cold weather is affecting the fundamental operation of the engine, and not a matter of keeping the cabin warm.

Now, my understanding is that there's still an electric heater present in that MY for those cold, cold days where the heat pump can't keep up. That is, I've heard, for days when we're seriously below 0F. We don't get a lot of that between New York and Boston, at least not these days. But even ICE's have issues when it gets that cold.

What's the year of your Tesla? Before or after heat pump?

 

[sleepydoc]

NE TN. Yes I see a drop but more in the 10-20% range. Not much different than the range decrease I saw on my ICE cars.

Not to be dismissive but you don't have winter in NE TN, just cooler weather.

Ahem. OK, New Jersey and the Northeast isn't Minnesota, but:

We got two cars over here. A 2018 M3 LR RWD with no heat pump. A 2021 MY LR with one.

When temperatures get well below freezing the M3's W-hr/mile goes from around 225-250 (summer) to 350+. If one drives long enough (we're talking 75-100 mile) the W-hr/mile might drop down to the low 300's on that car, presumably as things warm up somewhat. Short distances might see the W-hr/mile hit nearly 400. And that fits nicely with the 50% drop in range you're reporting. (All of that with using the seat heaters, which allows the cabin temperature to be in the mid-60's, Fahrenheit, comfortably.

The MY is a different story. It's got the heat pump. Weirdly enough, summer W-hr/mile is in the 250 W-hr/mile, not much different than the M3.

Wintertime: Say it's 20F outside. Initial W-hr/mile hits around 320 or so, but swiftly drops to 280 or thereabouts and stays there. So, yeah, there's a hit in cold weather, but it's nowhere near what the M3 is seeing. And not a whole lot different than what an ICE would see although, with an ICE, the cold weather is affecting the fundamental operation of the engine, and not a matter of keeping the cabin warm.

Now, my understanding is that there's still an electric heater present in that MY for those cold, cold days where the heat pump can't keep up. That is, I've heard, for days when we're seriously below 0F. We don't get a lot of that between New York and Boston, at least not these days. But even ICE's have issues when it gets that cold.

What's the year of your Tesla? Before or after heat pump?

I've got a 2020 Model Y - took delivery at the end of July. It definitely has a heat pump. No idea if it has an auxiliary resistive heater or not. if the temps are warmer (20+) the hit really isn't too bad but when they drop below zero it's significant.

I keep an eye on my tire pressures as we typically have to add air to them at least once season, especially when we have a cold snap.

One thing I have started doing is leaving the roof shade in place year round. Even with the coatings glass is a really poor insulator and if you put your hand close to the glass you can feel the cold air coming down. Adding the sunscreen provides a buffer layer and seems to help keep the cabin warmer.

 

[Tronguy]

Not to be dismissive but you don't have winter in NE TN, just cooler weather.

I've got a 2020 Model Y - took delivery at the end of July. It definitely has a heat pump. No idea if it has an auxiliary resistive heater or not. if the temps are warmer (20+) the hit really isn't too bad but when they drop below zero it's significant.

I keep an eye on my tire pressures as we typically have to add air to them at least once season, especially when we have a cold snap.

One thing I have started doing is leaving the roof shade in place year round. Even with the coatings glass is a really poor insulator and if you put your hand close to the glass you can feel the cold air coming down. Adding the sunscreen provides a buffer layer and seems to help keep the cabin warmer.

Interesting. I did a little Google searching, "What year did Tesla Model Y come with a heat pump?"

The answer appears to be: "On first introduction. Then all the other Teslas eventually got it."

But, at this link, there seems to be a claim that somewhere between 2020 (when the MY was first introduced?) and maybe 2022, when my SO got hers, Tesla was busy fixing bugs in the first rev of the heat pump system. The article was published 1/2023 and the words are, 'Eventually, Tesla fixed the issues last year.'

Which would've made the "corrected" versions around in January of 2022; but we got our new one in the mid-fourth quarter of 2021. Dunno.. But given that our your MY and ours seem (a) to have different performance in the cold (admittedly, yours is a colder clime) and (b) you definitely would have had the older... less optimized? version of the heat pump, we may have hit upon the differences.

As far as the electric heater goes: I watched a number of Sandy Munroe's teardown videos, and am pretty sure that the electric heater was always in the heat pump systems, to be used with it got Too Durned Cold.

Hm. Wonder if yours is stuck on or something? One would think that would throw an error code, right?

 

[sleepydoc]

Interesting. I did a little Google searching, "What year did Tesla Model Y come with a heat pump?"

The answer appears to be: "On first introduction. Then all the other Teslas eventually got it."

But, at this link, there seems to be a claim that somewhere between 2020 (when the MY was first introduced?) and maybe 2022, when my SO got hers, Tesla was busy fixing bugs in the first rev of the heat pump system. The article was published 1/2023 and the words are, 'Eventually, Tesla fixed the issues last year.'

Which would've made the "corrected" versions around in January of 2022; but we got our new one in the mid-fourth quarter of 2021. Dunno.. But given that our your MY and ours seem (a) to have different performance in the cold (admittedly, yours is a colder clime) and (b) you definitely would have had the older... less optimized? version of the heat pump, we may have hit upon the differences.

As far as the electric heater goes: I watched a number of Sandy Munroe's teardown videos, and am pretty sure that the electric heater was always in the heat pump systems, to be used with it got Too Durned Cold.

Hm. Wonder if yours is stuck on or something? One would think that would throw an error code, right?

I actually had the heat pump replaced under warranty a 12-18 months ago (can't remember exactly when) so there's no doubt that I have one. It may well be that there is a resistive heater and it was 'stuck' on simply because it was so cold it had to be on. No error codes either way and I don't recall my energy usage staying poor when it got warmer. I just remember having to turn around and pulling into the supercharger with 4% of charge.

 

[MP3Mike]

It may well be that there is a resistive heater and it was 'stuck' on simply because it was so cold it had to be on.

There is no restive heater in the heat pump equipped vehicles. If it is too cold for the heat pump's normal operations Tesla has a special "loop back" mode that it can run the heap pump in, as well as they can generate heat in the drive unit(s), can run the HVAC fan inefficiently to create heat, and can run the heat pump compressor inefficiently to create heat.

 

[DrGriz]

I just would like to double down on what @sleepydoc had to say. 20°F is not 0°F, and snow covered roads are not just cold-but-clear roads when it comes to efficiency. 50% reduction in range is well within my experience also.

 

[philly4]

I just would like to double down on what @sleepydoc had to say. 20°F is not 0°F, and snow covered roads are not just cold-but-clear roads when it comes to efficiency. 50% reduction in range is well within my experience also.

Yes, but 50% is near worse case and the original comment implied it was a "typical" winter. It's not typical even for folks who live in places where it gets that cold because winter is so long and there's plenty of winter where it isn't 0F no matter where you live.

I lived in Alaska where it wasn't unusual to get to -40F but it wasn't -40F all winter and it wasn't typical to have 50% less range most of the winter...if you preconditioned...though there were times that was the case. If you don't precondition, and take short trips, 50% less is super common even at 32F.

 

[DrGriz]

Yes, but 50% is near worse case and the original comment implied it was a "typical" winter. It's not typical even for folks who live in places where it gets that cold because winter is so long and there's plenty of winter where it isn't 0F no matter where you live.

I lived in Alaska where it wasn't unusual to get to -40F but it wasn't -40F all winter and it wasn't typical to have 50% less range most of the winter...if you preconditioned...though there were times that was the case. If you don't precondition, and take short trips, 50% less is super common even at 32F.

Where do you live? I’ve found as much as a 50% decrease in range during the winter in my MY.

Does it work? Yes. Is charging more of an issue than it is in the summer? Absolutely.

He said "as much as."

I am not sure what you are quibbling about. Sure, you don't see 50% winter loss in LA where it is 72 degrees ever day year round. And no one said "average," except you.

If you have to travel when it is -20F, it's a problem. It's not "hyperbole." That's the point.

 

[philly4]

what you are quibbling

The topic was how big a deal it is for winter driving. If you precondition and do a long drive where it actually matters a 50% reduction is a very edge case.

Example trip fom ABRP using OPs temp example: A 170 mile trip mostly highway at 85F averages 248 wh/mi. Same trip at -20F with heavy snow averages 353 wh/mi...much less than 496 wh/mi which would be 50% less range. These numbers also match my experience in said conditions. If you precondition 50% is hyperbole. If you don't precondition....50% could be low.

If you add a headwind to only winter you can easily get to 50% but then you aren't comparing apples to apples....which is probably what "experience" some report.

 

[DrGriz]

If you add a headwind to only winter you can easily get to 50%

So we agree! You can "easily" get to 50% in the winter (in, say, a snowstorm, which happens to occur in winter).

 

[philly4]

If you think it's fair to compare a headwind in winter to a tailwind in summer and call it "due to winter conditions" .... Do you also call it 50% increase because you drive up a mountain in the winter and compare that to flat summer driving?

 

[DrGriz]

If you think it's fair to compare a headwind in winter to a tailwind in summer and call it "due to winter conditions" .... Do you also call it 50% increase because you drive up a mountain in the winter and compare that to flat summer driving?

No, you are right. It's not all about wind, unless where you are wind is more likely in winter.

But we are talking about winter driving, not just temperature, which you seem to assume is the only factor.

There are also road conditions (snow and ice) which with the same tires will affect friction separately from temperature, which also takes a toll. And if you use better traction winter tires, another range bite.

@sleepydoc gave a specific example of the same trip winter vs. summer with a 50% range drop. You are saying that's an edge situation, and we are saying that edge situations can strand you. And you had better be prepared because they do happen. Not every day, but often enough that it can make the same trip impossible winter vs. summer. For myself, in the land of no chargers, it's a make or break decision. I can't take the same trip to visit family in my Model Y in winter.

 

[sleepydoc]

No, you are right. It's not all about wind, unless where you are wind is more likely in winter.

But we are talking about winter driving, not just temperature, which you seem to assume is the only factor.

There are also road conditions (snow and ice) which with the same tires will affect friction separately from temperature, which also takes a toll. And if you use better traction winter tires, another range bite.

@sleepydoc gave a specific example of the same trip winter vs. summer with a 50% range drop. You are saying that's an edge situation, and we are saying that edge situations can strand you. And you had better be prepared because they do happen. Not every day, but often enough that it can make the same trip impossible winter vs. summer. For myself, in the land of no chargers, it's a make or break decision. I can't take the same trip to visit family in my Model Y in winter.

Exactly.

‘Edge case’ implies that it’s a very rare occurrence. I would say it’s less common but hardly rare.

Regardless, as @DrGriz states, if that’s what the conditions are the car needs to be able to handle them. If it leaves you stranded it’s failed in it’s purpose.

 

[DrGriz]

Exactly.

‘Edge case’ implies that it’s a very rare occurrence. I would say it’s less common but hardly rare.

Regardless, as @DrGriz states, if that’s what the conditions are the car needs to be able to handle them. If it leaves you stranded it’s failed in it’s purpose.

Agree. Depending on where you are, it may not be infrequent.

Being stranded in freezing temps in the winter can be a life-threatening situation.

 

[alloverx]

NACS details video from Alex

 

[miimura]

NACS details video from Alex

The way he talks about Tesla being J1772 + CHAdeMO on Tesla connector is not technically correct. He should have said CANbus. The Supercharger and CHAdeMO use completely different protocol on top of CANbus siganling.

 

[mspohr]

SAE has finalized NACS Standard

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

The main reason for this is the standard is preserving NACS’ support for 277 volts, as opposed to the 208-240 voltage of J1772. This simple change unlocks a cascade of benefits that should smooth out several charging problems. Why does this matter? 277V is one phase of a three-phase 480V supply, which is the form that most commercial utility connections come in (particularly those that support DC chargers). Which means that secondary step-down transformers are no longer necessary for AC chargers, making EV charging installations cheaper and more efficient.

The new NACS standard instead uses a standardized receptacle – which is in fact the same one used in the EU and China – which can be plugged into with a ~$100-200 carry-along cable that EV drivers can keep in their car (and the receptacle does have a locking mechanism). Making each driver responsible for their own cable makes maintenance easier in public spaces where otherwise, nobody’s really willing to take ownership of ensuring cables don’t get abused.

Another potential upside here involves medium and heavy duty vehicles, which could charge at up to 52kW AC from the same receptacle as a light duty vehicle can charge at 20kW, by using 3 phases or 1 phase respectively. 20kW can be a bit on the low side for some larger vehicles – school buses and the like – so allowing those vehicles to charge at up to 52kW from the same place light duty can charge at 20kW would be a big boon as well.
Another potential upside here involves medium and heavy duty vehicles, which could charge at up to 52kW AC from the same receptacle as a light duty vehicle can charge at 20kW, by using 3 phases or 1 phase respectively. 20kW can be a bit on the low side for some larger vehicles – school buses and the like – so allowing those vehicles to charge at up to 52kW from the same place light duty can charge at 20kW would be a big boon as well.

 

[wws]

SAE has finalized NACS Standard

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

The main reason for this is the standard is preserving NACS’ support for 277 volts, as opposed to the 208-240 voltage of J1772. This simple change unlocks a cascade of benefits that should smooth out several charging problems. Why does this matter? 277V is one phase of a three-phase 480V supply, which is the form that most commercial utility connections come in (particularly those that support DC chargers). Which means that secondary step-down transformers are no longer necessary for AC chargers, making EV charging installations cheaper and more efficient.

The new NACS standard instead uses a standardized receptacle – which is in fact the same one used in the EU and China – which can be plugged into with a ~$100-200 carry-along cable that EV drivers can keep in their car (and the receptacle does have a locking mechanism). Making each driver responsible for their own cable makes maintenance easier in public spaces where otherwise, nobody’s really willing to take ownership of ensuring cables don’t get abused.

Another potential upside here involves medium and heavy duty vehicles, which could charge at up to 52kW AC from the same receptacle as a light duty vehicle can charge at 20kW, by using 3 phases or 1 phase respectively. 20kW can be a bit on the low side for some larger vehicles – school buses and the like – so allowing those vehicles to charge at up to 52kW from the same place light duty can charge at 20kW would be a big boon as well.
Another potential upside here involves medium and heavy duty vehicles, which could charge at up to 52kW AC from the same receptacle as a light duty vehicle can charge at 20kW, by using 3 phases or 1 phase respectively. 20kW can be a bit on the low side for some larger vehicles – school buses and the like – so allowing those vehicles to charge at up to 52kW from the same place light duty can charge at 20kW would be a big boon as well.

A couple things I'm wondering:

1.) How many non-Tesla manufacturers support 277V? (I know Tesla has supported it since the Model S first came out.)

2.) Although the article doesn't mention it, did they extended 120V charging to 24 amps? This would help folks that camp at RV parks fully utilize TT-30 receptacles. Again, Tesla has supported it all along. (Though the first couple years of Model S were limited to 20 amps.) Some manufacturers cap 120V at 12 amps no matter what the EVSE says is safe. Others allow more.

 

[mspohr]

A couple things I'm wondering:

1.) How many non-Tesla manufacturers support 277V? (I know Tesla has supported it since the Model S first came out.)

2.) Although the article doesn't mention it, did they extended 120V charging to 24 amps? This would help folks that camp at RV parks fully utilize TT-30 receptacles. Again, Tesla has supported it all along. (Though the first couple years of Model S were limited to 20 amps.) Some manufacturers cap 120V at 12 amps no matter what the EVSE says is safe. Others allow more.

Since this is new, I think everyone will have to look at it and then publish what they support.