Just Did My First DCFC at EA - 2 Questions

[rcechinel]

Can you share the source of this graph, especially if they have it for Mme for both 150 and 350kW stations?

https://insideevs.com/news/586886/how-long-to-charge-rivian-r1t/amp/

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[rcechinel]

Can you share the source of this graph, especially if they have it for Mme for both 150 and 350kW stations?

I haven't found a similar analysis for the mach-e post charge curve update earlier this year.

 

[4sallypat]

70 EVs all trying to use the same station ... Not my idea of fun, but best of luck.

Idle time starts after the grace period, when the charging stops. So if you, for example, set the destination to charge to 90% then the vehicle would stop at 90% and any time left plugged in after the grace period (normally 10 minutes for EA) would be idle time. They are correct that it has nothing to do with charge percentage.

Yup, the promoter had to cut off Tesla owners from joining this group drive.

50 Teslas are in the drive group which is max for the number of working Tesla Superchargers in Baker.

Add about 15 other non Teslas (Lucid, Polestar 2, MME, Lightning, Bolt EUV, Rivian) who are using the EA DCFC next to the Tesla SC.

Going to be exciting to see that many vehicles traveling together in a line on the 15 freeway.

I wonder where we are all meeting on the Hoover Dam destination since parking is so limited...

 

[DevSecOps]

I haven't found a similar analysis for the mach-e post charge curve update earlier this year.

This was when it was a bit colder outside so it wasn't accepting charge as fast, but it was post charge curve.

https://www.macheforum.com/site/thr...ve-and-maybe-power-delivery.13747/post-341965

I'll get an updated graph this week when I DCFC. I just haven't logged those parameters in a while, but easy enough to do.

 

[Tampamike]

Are you using Plug and Charge / Blue Oval Network account, or are you using EA's app? We had this issue with EA's app.

P&C with Blue Oval free for a year.

 

[GreaseMonkey]

I'll get an updated graph this week when I DCFC. I just haven't logged those parameters in a while, but easy enough to do.

Thank you.

I don’t think anyone here is trying to game the system. But with lack of real-life data, we tend to default to our gut feel or subjective experiences.

 

[DevSecOps]

Thank you.

I don’t think anyone here is trying to game the system. But with lack of real-life data, we tend to default to our gut feel or subjective experiences.

What data do you think we're missing? I think the problem is that people just don't want to trust those of us who have looked at the data and compiled it. Almost all of my posts are supported with data and charge curve/power delivery is one that many of us covered extensively.

We've been through this before so normally when we cross that bridge, I don't go back to it.

In this thread we go over charge curve, amps delivered etc. It's all in there somewhere. If there's something specific you are looking for let me know and I can point you to it or gather the data this week.

 

[GreaseMonkey]

What data do you think we're missing? I think the problem is that people just don't want to trust those of us who have looked at the data and compiled it. Almost all of my posts are supported with data and charge curve/power delivery is one that many of us covered extensively.

We've been through this before so normally when we cross that bridge, I don't go back to it.

In this thread we go over charge curve, amps delivered etc. It's all in there somewhere. If there's something specific you are looking for let me know and I can point you to it or gather the data this week.

Charge curves for Mme on both a 150kW and 350kW from same SOC, say 20% to 90%.

In other words, how many minutes would I save if I use a 350 vs 150?

 

[DevSecOps]

Charge curves for Mme on both a 150kW and 350kW from same SOC, say 20% to 90%.

In other words, how many minutes would I save if I use a 350 vs 150?

I can do that. I can guarantee you right now however that it would be less than 1 minute.

There's just a very brief moment that a 350 gets a little higher than a 150. You have to also remember that because the charger says 160 (as an example), that doesn't mean the car gets 160. That is the cumulative power consumption including the charger loss, cooling etc. That's what you are getting billed for, which is a larger number than the car can receive. Therefore a 150 will max, with all the overhead at a lower number than the car will max at. The key takeaway here however is that the MME will only sustain such high power consumption for 1-2 minutes before dropping to levels suitable for a 150 unit. The overall savings in time is negligible and not worth hogging a 350 charger that another vehicle can FULLY take advantage of.

 

[RickMachE]

P&C with Blue Oval free for a year.

Right. So you cannot suspend an EA account by disconnecting at the charger, because you aren't using it.

 

[GreaseMonkey]

The key takeaway here however is that the MME will only sustain such high power consumption for 1-2 minutes before dropping to levels suitable for a 150 unit. The overall savings in time is negligible and not worth hogging a 350 charger that another vehicle can FULLY take advantage of.

I know this will make no sense to you, but some members on this site claim that the gain in power is sustained throughout the charge session...making the charge curve of a 350kW charger look similar to that of a 150kW one, but at higher kW. That's the reason why I was asking for the curves. If the gain is only sustained for a couple of minutes, you would be absolutely right in charging on a 150kW unless one is unavailable.

 

[DevSecOps]

I know this will make no sense to you, but some members on this site claim that the gain in power is sustained throughout the charge session...making the charge curve of a 350kW charger look similar to that of a 150kW one, but at higher kW. That's the reason why I was asking for the curves. If the gain is only sustained for a couple of minutes, you would be absolutely right in charging on a 150kW unless one is unavailable.

I'm not sure why you say it won't make sense to me unless that's a dig. I understand what people say. The problem is that they have nothing to back it up. I don't believe 1/2 of what people say without proof because anyone can say anything. Their observations could also be because a charger isn't working at full capacity, different times of the year, etc.

There's nothing in a 350 unit that would cause higher sustained charging. The car receives power in the form of Volts and Amps. A 150 EA station has a max amperage of 350, while a 350 EA station has a max amperage of 500amps. As you can see in the below image (focus on the red line), the car doesn't request more than 350, which is = to a 150EA. At the start it appears that it could get more than 350, which is why a 500amp EA 350 will provide a little more power at the start. That is true, and it's not disputed.

The issue is that once that short lived burst where we are slightly over 350amps is over, we drop well below the limit of an EA 150. The max I've seen the MME top out at is 380amps although I believe it's limited at 400amps. Additionally, all MMEs come with a window sticker that says 150kw is the max.

I'm also attaching a PDF that shows why we don't want to use a 350 because other cars can take advantage of it. This is older and now there's even more 800v system vehicles out there. You get the idea though. Note the Porsche vs the MME.

 

[GreaseMonkey]

I'm not sure why you say it won't make sense to me unless that's a dig. I understand what people say. The problem is that they have nothing to back it up. I don't believe 1/2 of what people say without proof because anyone can say anything. Their observations could also be because a charger isn't working at full capacity, different times of the year, etc.

There's nothing in a 350 unit that would cause higher sustained charging. The car receives power in the form of Volts and Amps. A 150 EA station has a max amperage of 350, while a 350 EA station has a max amperage of 500amps. As you can see in the below image, the car doesn't request more than 350, which is = to a 150EA. At the start it appears that it could get more than 350, which is why a 500amp EA 350 will provide a little more power at the start. That is true, and it's not disputed.

The issue is that once that short lived burst where we are slightly over 350amps is over, we drop well below the limit of an EA 150. The max I've seen the MME top out at is 380amps although I believe it's limited at 400amps. Additionally, all MMEs come with a window sticker that says 150kw is the max.

Not a dig, bro. I knew you would default to explaining the science. And based on the science, the argument would not make any sense. Thanks for the explanation.

 

[DevSecOps]

Not a dig, bro. I knew you would default to explaining the science. And based on the science, the argument would not make any sense. Thanks for the explanation.

I'll still do the experiment because I DCFC anyway. So long as there's a 350 open and no one needs it. Give me a week or two.

 

[dbsb3233]

I can do that. I can guarantee you right now however that it would be less than 1 minute.

There's just a very brief moment that a 350 gets a little higher than a 150. You have to also remember that because the charger says 160 (as an example), that doesn't mean the car gets 160. That is the cumulative power consumption including the charger loss, cooling etc. That's what you are getting billed for, which is a larger number than the car can receive. Therefore a 150 will max, with all the overhead at a lower number than the car will max at. The key takeaway here however is that the MME will only sustain such high power consumption for 1-2 minutes before dropping to levels suitable for a 150 unit. The overall savings in time is negligible and not worth hogging a 350 charger that another vehicle can FULLY take advantage of.

That's the math I alluded to earlier, and I came up with a savings of just seconds on a 350 vs a 150.

That's assuming, of course, that the rest of the curve beyond that initial 2-minute peak is the same on each. Which theoretically it should be as long as each charger is working to it's full capacity (since it's the car that limits the power and sets the charge curve, not the charger, up to the charger max of course).

When it's all working right, we peak around 163kW on a 350. And I think about 146kW on a 150 (IIRC). I might be wrong on that, but that number is sticking in my mind. It takes maybe 30 seconds to ramp up to the peak at the start, and seems to start falling off that around the 2 minute mark. So I'm figuring 90 seconds of peak. The extra 17kw for 90 seconds is 0.425kWh (17 / 60 * 1.5 minutes).

When charging in the area of those peaks (roughly 150kW), that's around 2.5kWh per minute (250 / 60). 0.425kWh is 1/6th that, so about 10 seconds. Even if one only peaks at 120kW for that 90 seconds instead of 163, that's only a difference of 1.1kWh (26 seconds).

It's hardly any difference between the 350 vs 150. And it should be slightly less risky for heating up the battery and contactors.

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