VW Fallout: $2.0 Billion for ZEV Infrastructure Buildout

[Saghost]

Thanks for the article. A couple of points:

"The Chevrolet Bolt can charge at up to 55 kW which is 20 percent faster than at older 50 kW chargers installed in North America today"

Should that be 10%? Or is the issue with the current the 50kW chargers are capable of delivering for a given voltage?


"The only car known to utilize 350 kW charging is the Porsche Taycan (previously known as the Mission E) and it is not expected until late 2019."

You might want to consider saying "claimed to"... as I don't think it's been proven yet. What's more, the EA stations are 150KW @ 1000V, and as the Taycan is an 800V architecture (with peak power delivery somewhere around 700V before taper), it's not likely that it will see more than 250kW unless the ABB chargers EA is installing are using liquid cooled cables and handles we are unaware of to get past the 350A rating....

The 20% is correct. The charger is rated for max amperage at max voltage, but the cars are never drawing the max amperage but the time they hit the max voltage (and many cars can't reach the charger's max voltage.)

The Bolt tops out in the mid forties on the best previously available chargers, the 125A limit ones.

 

[scaesare]

The 20% is correct. The charger is rated for max amperage at max voltage, but the cars are never drawing the max amperage but the time they hit the max voltage (and many cars can't reach the charger's max voltage.)

The Bolt tops out in the mid forties on the best previously available chargers, the 125A limit ones.

Ah, I thought that might be the case... I couldn't remember what the 50KW chargers could do....

 

[SageBrush]

"The Chevrolet Bolt can charge at up to 55 kW which is 20 percent faster than at older 50 kW chargers installed in North America today"

Should that be 10%? Or is the issue with the current the 50kW chargers are capable of delivering for a given voltage?

I don't know why but I think Bolts maxed out at 45 kW on the old chargers. If they now max out at 55 kW then that would be a 55/45 = 122% improvement.

Woohoo !! .... not

 

[Jeff N]

"The Chevrolet Bolt can charge at up to 55 kW which is 20 percent faster than at older 50 kW chargers installed in North America today"

Should that be 10%? Or is the issue with the current the 50kW chargers are capable of delivering for a given voltage?

The Bolt tops out in the mid forties on the best previously available chargers, the 125A limit ones.

Right. The older chargers max out at 125A while the Bolt itself maxes out at 150A. Since the newer chargers that Electrify America is installing can do more than 150A it ends up meaning the Bolt can charge during the lower half of its battery pack at 150A vs 125A or 20% higher current and thus 20% higher power.

"The only car known to utilize 350 kW charging is the Porsche Taycan (previously known as the Mission E) and it is not expected until late 2019."

You might want to consider saying "claimed to"... as I don't think it's been proven yet. What's more, the EA stations are 150KW @ 1000V, and as the Taycan is an 800V architecture (with peak power delivery somewhere around 700V before taper), it's not likely that it will see more than 250kW unless the ABB chargers EA is installing are using liquid cooled cables and handles we are unaware of to get past the 350A rating....

CCS cables and plugs rated much above 250A require cooling and the 150 kW chargers being installed support at least 350A so every CCS cable and plug at these Electrify America sites is liquid-cooled.

Every Electrify America location so far includes at least one 350 kW charging space and typically two spaces. All signs point toward this trend continuing at most future locations. The 350 kW units are still supporting 350A (but at up to 900-1000V instead of up to 500V).

Also, I don’t think the Taycan’s peak power delivery will be “somewhere around 700V”. I believe it’s nominal battery pack voltage is near 800V much like the nominal pack voltage of the Jaguar I-PACE and Audi e-tron are near 400V (most EVs including Tesla cars have a nominal voltage of about 350V). Charging requires an inflow voltage higher than the open-circuit pack voltage. The charging voltage at around 55% on these higher voltage I-PACE and e-tron packs is likely around 420V so I expect the peak charging voltage of the Taycan to be twice that and close to 840V.

Finally, we don’t know the details of how the charger cabinets are configured for the “350 kW” cables. Although people generally say 350A, the actual CCS specs allow 400A and many CCS charger vendors including ABB are claiming to support up to 500A in some configurations.

 

[SageBrush]

Also, I don’t think the Taycan’s peak power delivery will be “somewhere around 700V). I believe it’s nominal battery pack voltage is near 800V much like the nominal pack voltage of the Jaguar I-PACE and Audi e-tron are near 400V (most EVs including Tesla cars have a nominal voltage of about 350V). Charging requires an inflow voltage higher than the open-circuit pack voltage so I expect the peak charging voltage to be closer to 740V.

Presuming the OC voltage is 700v, is it right to then estimate the charging losses as 1 -700/740 = 5.6% ?

Also, am I calculating correctly that peak Amps into a Tesla are in the 300 range ? Why do they not also require liquid charging ?

 

[Jeff N]

Presuming the OC voltage is 700v, is it right to then estimate the charging losses as 1 -700/740 = 4.4% ?

Sorry, you saw and responded to my message before I fixed a typo. I meant to say peak charging voltage on the Taycan would be around 840V, not 740V. Please re-read my updated post.

As for charging losses for the Taycan, I suspect they will be not too much more than existing fast charging bigger battery cars like the Model S/X since the inflow current is about the same.

 

[SageBrush]

Sorry, you saw and responded to my message before I fixed a typo. I meant to say peak charging voltage on the Taycan would be around 840V, not 740V. Please re-read my updated post.

Noted, but I want to get a handle on estimating charging losses. Would 1 - 800/840 be ballpark ?

 

[Jeff N]

Noted, but I want to get a handle on estimating charging losses. Would 1 - 800/840 be ballpark ?

I haven’t made a careful study of typical charging losses inside the vehicle during high-power DC charging.

Clearly, there will be heat loss from all that current flowing through cables and busbars into the pack and cells. In addition, there will be energy expended by the battery pack cooling system to help move that heat out of the way. I’ll make a wild guess that it could account for an overall 5-10% vehicle charging loss depending upon charging time and ambient temperatures. I don’t really claim to know.

 

[scaesare]

CCS cables and plugs rated much above 250A require cooling and the 150 kW chargers being installed support at least 350A so every CCS cable and plug at these Electrify America sites is liquid-cooled.

Every Electrify America location so far includes at least one 350 kW charging space and typically two spaces. All signs point toward this trend continuing at most future locations. The 350 kW units are still supporting 350A (but at up to 900-1000V instead of up to 500V).

Interesting that CCS requires liquid cooling at such low amperages. Tesla's superchargers deliver nearly 350A without... and in a smaller connector package to boot.

So at 350A, even at 800V (assuming that's nominal), that's about 280kW from a 350kW charger. (although the ABB spec says 375A)

Also, I don’t think the Taycan’s peak power delivery will be “somewhere around 700V”. I believe it’s nominal battery pack voltage is near 800V much like the nominal pack voltage of the Jaguar I-PACE and Audi e-tron are near 400V (most EVs including Tesla cars have a nominal voltage of about 350V). Charging requires an inflow voltage higher than the open-circuit pack voltage. The charging voltage at around 55% on these higher voltage I-PACE and e-tron packs is likely around 420V so I expect the peak charging voltage of the Taycan to be twice that and close to 840V.

Interesting, that several articles I've seen compare their 800V system to Tesla's 400V packs... so it appears they might be comparing apples to oranges in using nominal vs peak.

If that's the case then if then assuming the car can accept and a single charge cable can deliver ~437A @ 800V then we'd see 350kW charging.

Finally, we don’t know the details of how the charger cabinets are configured for the “350 kW” cables. Although people generally say 350A, the actual CCS specs allow 400A and many CCS charger vendors including ABB are claiming to support up to 500A in some configurations.

Yeah,, I also am unsure what ABB means when they say:

"A single power cabinet system can charge a 400 V car at full 150 kW (375 A) continuously. With Dynamic DC power sharing technology, a two power cabinet Dynamic DC charger configuration can charge two EVs simultaneously, distributed between two charge posts, with up to 350 kW and 500 A available, while optimizing the available grid connection"

Does that allow for a single cable on one post to deliver the full 350kW?​

 

[miimura]

"A single power cabinet system can charge a 400 V car at full 150 kW (375 A) continuously. With Dynamic DC power sharing technology, a two power cabinet Dynamic DC charger configuration can charge two EVs simultaneously, distributed between two charge posts, with up to 350 kW and 500 A available, while optimizing the available grid connection"

Does that allow for a single cable on one post to deliver the full 350kW?

If the second stall is vacant, I see no reason it can't charge one vehicle at full speed. My understanding is that the second cabinet is required to stack the voltage above 500VDC. How they do power splitting between the two stalls is unknown. Presumably the scheme is similar to Superchargers where each cabinet is composed of multiple charger modules that can be switched between the stalls.

 

[scaesare]

If the second stall is vacant, I see no reason it can't charge one vehicle at full speed. My understanding is that the second cabinet is required to stack the voltage above 500VDC. How they do power splitting between the two stalls is unknown. Presumably the scheme is similar to Superchargers where each cabinet is composed of multiple charger modules that can be switched between the stalls.

I would expect the second cabinet would be necessary for more current, not voltage.

 

[miimura]

I would expect the second cabinet would be necessary for more current, not voltage.

That does make sense. However, they don't say what the capability of a single cabinet is when charging a 800V car, or if it's even possible. If one cabinet can also charge a 800V car at 150kW, then adding current with the second cabinet to bring it up 350kW makes sense.

What doesn't make sense is how you get 175kW per cabinet when there are two, but only 150kW when there is only one. Someone should really look at the rating label on the cabinets for the 350kW chargers. If one cabinet is 200 amps per phase on 277Y480V service, then at 90% efficiency it's not going to push more than 150kW to the car per cabinet. For reference, Tesla Supercharger cabinets are rated at 192 amps per phase on 277Y480V service.

 

[Jeff N]

If that's the case then if then assuming the car can accept and a single charge cable can deliver ~437A @ 800V then we'd see 350kW charging.

As I mentioned earlier, I suspect that peak charging power comes at a somewhat higher charging voltage closer to 840V.

In any case, the ABB materials imply that a 2-cabinet install is required for “350 kW” and that it inherently supports up to 500A when only one of the two pedestals connected to the pair of charging cabinets is active.

My understanding is that the second cabinet is required to stack the voltage above 500VDC.

I think the ABB link is vague about the supported voltage range on one-cabinet “175 kW” installs. My guess is that it actually supports up to 920V and 375A but is limited to only 175 kW and the second cabinet boosts the current capability. That’s similar to how the flexibly-configurable ChargePoint Express hardware works.

If one cabinet is 200 amps per phase on 277Y480V service, then at 90% efficiency it's not going to push more than 150kW to the car per cabinet. For reference, Tesla Supercharger cabinets are rated at 192 amps per phase on 277Y480V service.

The classic Tesla Supercharger specs say “90%” efficient but recent CCS chargers from multiple makers say 95-97% efficient.

 

[scaesare]

That does make sense. However, they don't say what the capability of a single cabinet is when charging a 800V car, or if it's even possible. If one cabinet can also charge a 800V car at 150kW, then adding current with the second cabinet to bring it up 350kW makes sense.

What doesn't make sense is how you get 175kW per cabinet when there are two, but only 150kW when there is only one. Someone should really look at the rating label on the cabinets for the 350kW chargers. If one cabinet is 200 amps per phase on 277Y480V service, then at 90% efficiency it's not going to push more than 150kW to the car per cabinet. For reference, Tesla Supercharger cabinets are rated at 192 amps per phase on 277Y480V service.

I'm relatively certain a single cabinet can charge an 800V car.

Here are the specs per cabinet:

 

[scaesare]

As I mentioned earlier, I suspect that peak charging power comes at a somewhat higher charging voltage closer to 840V.

Assuming a 216S pack implied by several places for 800V nominal system, that would be nearly 70% SOC.

In any case, the ABB materials imply that a 2-cabinet install is required for “350 kW” and that it inherently supports up to 500A when only one of the two pedestals connected to the pair of charging cabinets is active.


I think the ABB link is vague about the supported voltage range on one-cabinet “175 kW” installs. My guess is that it actually supports up to 920V and 375A but is limited to only 175 kW and the second cabinet boosts the current capability. That’s similar to how the flexibly-configurable ChargePoint Express hardware works.

Agreed... In the spec snippet I posted above, it appears to that 920V/375A is one what one cabinet can deliver at peak.

 

[Jeff N]

As I mentioned earlier, I suspect that peak charging power comes at a somewhat higher charging voltage closer to 840V.

Assuming a 216S pack implied by several places for 800V nominal system, that would be nearly 70% SOC.

Let’s look at a Tesla S 85 charging video from Bjorn Nyland.

At the point of first peak power, the charging current is 273A and the charging voltage is 367V for a charging power just over 100 kW.

This happens when the battery is about 25% full. This is a pack with 96S and a nominal voltage of about 350V, but it is 367V at 25% when supercharging. The 367V / 96S is 3.823V per cell. Now multiple by 216S and you get 826V.

At 50% full the Model S 85 battery is being charged at 380V. Do the same math and you get an extrapolated charging voltage of 855V.

That gives a good sense what the peak charging power voltage of the Taycan might be like — somewhere between 826-855V and the average of that is 840.5V.

 

[miimura]

Assuming a 216S pack implied by several places for 800V nominal system, that would be nearly 70% SOC.


Agreed... In the spec snippet I posted above, it appears to that 920V/375A is one what one cabinet can deliver at peak.

That would be either 920V or 375A because the cabinet has a maximum output of 160kW continuous. At 920VDC, that's only 174 amps. At 375A, that's only 426 volts.

That image of the specs makes it clear that it can charge an 800V car. However, it is from the European version due to the grid spec. There is also a North American one that states 3-phase 480V.

 

[miimura]

This is a pack with 96S and a nominal voltage of about 350V, but it is 367V at 25% when supercharging. The 367V / 96S is 3.823V per cell. Now multiple by 216S and you get 826V.

At 50% full the Model S 85 battery is being charged at 380V. Do the same math and you get an extrapolated charging voltage of 855V.

That gives a good sense what the peak charging power voltage of the Taycan might be like — somewhere between 826-855V and the average of that is 840.5V.

Where did the 216S pack configuration come from? I haven't been following Taycan news that closely. Was that technical spec released?

 

[Jeff N]

Where did the 216S pack configuration come from? I haven't been following Taycan news that closely. Was that technical spec released?

It’s speculation. The Audi e-tron (like the I-PACE) is 108S. So, it wouldn’t be surprising if the Taycan was twice that or 216S. I’ve also heard another line of evidence that is consistent with that speculation.

 

[miimura]

It’s speculation. The Audi e-tron (like the I-PACE) is 108S. So, it wouldn’t be surprising if the Taycan was twice that or 216S. I’ve also heard another line of evidence that is consistent with that speculation.

Okay, sure. The other possibility is that the pack and drivetrain is still less than 500VDC and they are using a DC-DC charging system like what Continental announced. They apparently developed a high efficiency high power step down converter so that the charging cable is higher voltage and lower current, but it still pushed the power into a more conventional pack.