DCFC GTPE

[jamelski]

Man it’s been a while but I’ll take 160 KW in Fairfield. ?

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[silverelan]

Man it’s been a while but I’ll take 160 KW in Fairfield. ?

Two minutes, tops! It’s still nice though.

 

[VaporTrails]

Is this just like the 5-second limit, but the other direction?

 

[jamelski]

Best two minutes of your life

 

[silverelan]

Is this just like the 5-second limit, but the other direction?

I forget now who made this chart showing the original charge curve overlaid with the new charge curve from about 3% state of charge. Regardless, you can see the short burst of 150-160kW at the start for two minutes then it settles down to about 110kW for 12-13 mins then drifts downwards for another 7-8 mins so that at the 20 minute mark, you will have gotten 40% SoC back. It’ll then sit at 75-80kW up to 80% SoC.

This behavior is pretty consistent when you plug in anywhere from 0-40% and the timing is modified but still similar when you plug in at higher SoC.

 

[Teleks]

Can someone quickly give me the basics of charging speed? Unfortunately I still don't get it.

I've charged my Mach-E at a few different 150 kW chargers here in the New England area, and always end up with something between 30 kW and 70 kW, but have never seen any more, even when I'm not sharing the station with someone else. This is probably something I should know, but I have to admit I was never sure if that's because the chargers do less than they should, or because the Mach-E is limiting power input.

Yesterday I charged for the first time at a 350 kW charger from 35% to 80% and for the very first time saw faster charging. Started at 130 kW and slowly went down until it was at around 100 kW at 80%. Which also doesn't line up with what @silverelan posted.

I'm sure there have already been plenty of threads about this here. But I feel like I'm very late to the game (of figuring this stuff out) and have always been a little confused about the discussions.

 

[silverelan]

Can someone quickly give me the basics of charging speed? Unfortunately I still don't get it.

I've charged my Mach-E at a few different 150 kW chargers here in the New England area, and always end up with something between 30 kW and 70 kW, but have never seen any more, even when I'm not sharing the station with someone else. This is probably something I should know, but I have to admit I was never sure if that's because the chargers do less than they should, or because the Mach-E is limiting power input.

Yesterday I charged for the first time at a 350 kW charger from 35% to 80% and for the very first time saw faster charging. Started at 130 kW and slowly went down until it was at around 100 kW at 80%. Which also doesn't line up with what @silverelan posted.

I'm sure there have already been plenty of threads about this here. But I feel like I'm very late to the game (of figuring this stuff out) and have always been a little confused about the discussions.

If I read your post correctly, you were pulling 100kW at like 78%?

Do you have your session details handy that you can share? Your Ford Pass app with charging session details might have some info as would your EA app showing your charging history.

 

[Teleks]

Sure, here you go!

I did the math, and apparently I had an AVERAGE charging speed (from 34% to 80%) of 106.3 kW. That's from the info of the EA screen: 42.518 kWh * (1h/24min)h = 106.3 kW.

Which is a lot more than in your graph, right? From 35% to 80% it should be 75 kW for 90% of the time. In that graph it's probably an average of maybe 77 kW.

I don't have a screenshot of how fast it was charging at 80%, but I think it was still pretty close to 100 kW. Attached you can see a screenshot of it being 100 kW at 60%.

 

[RickMachE]

Sure, here you go!

I did the math, and apparently I had an AVERAGE charging speed (from 34% to 80%) of 106.3 kW. That's from the info of the EA screen: 42.518 kWh * (1h/24min)h = 106.3 kW.

Which is a lot more than in your graph, right? From 35% to 80% it should be 75 kW for 90% of the time. In that graph it's probably an average of maybe 77 kW.

I don't have a screenshot of how fast it was charging at 80%, but I think it was still pretty close to 100 kW. Attached you can see a screenshot of it being 100 kW at 60%.

Charging slows at 60%, and then significantly at 80%. The accurate read on charging speed would be on the EA screen. FordPass telling you that you're at 100kW at 63% is likely inaccurate.

If you do the math, your average kW / minute is 1.75. That's in line with many of my charges. At 63% it's likely right where the chart shows.

 

[Teleks]

Charging slows at 60%, and then significantly at 80%. The accurate read on charging speed would be on the EA screen. FordPass telling you that you're at 100kW at 63% is likely inaccurate.

If you do the math, your average kW / minute is 1.75. That's in line with many of my charges. At 63% it's likely right where the chart shows.

Not sure if I get it. You're saying my math is wrong? The EA screen says it added 42 kWh in only 24 minutes.. which clearly means it was charging with more than 100 kW on average if I'm not totally confused right now. 24 minutes is exactly a 2.5th of an hour.. so you just got to multiply 42 with 2.5 and that should be the average kW

Also what's kW / minute? I don't understand that unit I have to admit. Or do you mean kWh/minute?

I do have a photo of the EA screen saying it's charging with 125 kW at 40% btw.. would that convince you I'm not on that plot?

 

[RickMachE]

Not sure if I get it. You're saying my math is wrong? The EA screen says it added 42 kWh in only 24 minutes.. which clearly means it was charging with more than 100 kW on average if I'm not totally confused right now. 24 minutes is exactly 2.5th of an hour.. so you just got to multiply 42 with 2.5 and that should be the average kW

Also what's kW / minute? I don't understand that unit I have to admit. Or do you mean kWh/minute?

I do have a photo of the EA screen saying it's charging with 125 kW at 40% btw.. would that convince you I'm not on that plot?

You say tomato, I say tomatoe...

Your math is fine.
EA screen saying it was at X speed is also fine.
FordPass saying it's at 100kW at 63% is suspect. It assumes every field got updated, and FordPass is known for inaccuracy.

I'm saying your charge rate of 1.75kW per minute is right on the money for a normal charge. I calculate that for every charge. It's not OMG fast, by any means.

That might be one of their newest chargers, can't check because you blurred out the charger info.

 

[silverelan]

25 mins to go 34% to 80% sounds correct.

The MME adds 40% SoC in 20 minutes so your charge session lines up for a few minutes to add an additional 6%.

The consistent charge profile has its pros and cons. The biggest benefit is that there’s zero incentive to drive the car all the way down to a low SoC. Cars like the ID4 get max charging speeds down low in the pack and then a consistent taper as SoC goes up. In contrast, the MME gets the same charging experience across a huge spectrum of the SoC.

 

[Teleks]

Hmm, I still don't get it.

Also, don't get me wrong, I never wanted to claim my Mach-E charges faster than everyone else's haha. I just don't understand how the plot that @silverelan originally posted could be showing what my Mach-E was charging with yesterday. Or are you just all agreeing that the plot is not correct for my experience yesterday? @silverelan what do you mean by "consistent charge profile"? Does that plot show the consistent charge profile or not?

To summarize my confusion again: The plot shows an average charging speed of slightly more than 75 kW when charging from 35% to 80%. I was charging with well over 100 kW on average when charging from 35% to 80%. That's a huge difference and the graph seems to disagree with what I did yesterday.

@RickMachE I also still don't get what kind of unit kW/minute is supposed to be. You're talking about a charging speed (= charging rate), right? The commonly used unit kW also just defines the charging speed - why would you divide a rate by time? So the only thing that could make sense is kWh/min. Which to me seems kind of silly, because you have two units of time in there (h and min) that cancel each other out. 1 kWh/min would be exactly 60 kW. What you're saying would line up with what I calculated, because 1.75 kWh/min = 105 kW (which is pretty close to my 106 kW). So I assume the unit you're talking about is in fact kWh/min. But I don't understand why you would use that instead of just kW.

If I get that all right, you would also be saying that an average of >100 kW for >40% is normal. So why is that not reflected in the graph that @silverelan originally posted?

 

[Teleks]

Ohhhh, it just clicked.. maybe I understand now. The plot doesn't show the absolute SoC, it states the added SoC? Is that what this is all about? Like it should rather say "Δ% SoC" on the x-axis? So my 35% SoC yesterday is equivalent to 5% SoC in that plot? It doesn't matter if you're at 1% SoC or at 70% SoC, initially you'll always be charging very fast with >>100 kW??

Edit: Just read more about it in other threads. It seems to be the case! So yes, this is what I didn't understand. Now it makes sense.

@RickMachE: However, I still think kW/min must be wrong, and I don't understand why anyone would use kWh/min when it's basically the same as just kW. ?

 

[silverelan]

Ohhhh, it just clicked.. maybe I understand now. The plot doesn't show the absolute SoC, it states the added SoC? Is that what this is all about? Like it should rather say "Δ% SoC" on the x-axis? So my 35% SoC yesterday is equivalent to 5% SoC in that plot? It doesn't matter if you're at 1% SoC or at 70% SoC, initially you'll always be charging very fast with >>100 kW??

Edit: Just read more about it in other threads. It seems to be the case! So yes, this is what I didn't understand. Now it makes sense.

@RickMachE: However, I still think kW/min must be wrong, and I don't understand why anyone would use kWh/min when it's basically the same as just kW. ?

For the most part, yes. I mean, I don’t actually know what it looks like at 70% when you plug in, but it’ll be pretty quick.

The main thing to remember is that 20 mins on a 150kW charger gets you 40% SoC back.

So you can road trip from 100% down to 40% (130-140 miles), then stop for 20 mins and get back up to 80%, then drive another 150-160 miles with 10% on arrival.

The sucky part is that the MME takes nearly 45 mins to go 10% to 80%.

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