Actual charging time almost 2X longer vs predicted.

[SteveInKirkland]

If only evkx.net provided a model that estimated charge time based on starting battery temperature too.

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[Petzi]

The charging station delivered less than 50% of the requested power...taking a 15 minute estimate to 28 minutes, which was correctly calculated within a minute of the charge starting. This is not "over 2X wrong".

It was showing 15 minutes from 37 to 80%, which is the correct estimate if the 350kW station was operating normally.

...it didn't.


No need: https://evkx.net/models/porsche/macan/macan_4/chargingcurve/

thank you @seabird !

and because the clarifying information is overlooked here so often, once again the information provided by @seabird. this answers all questions and thats how the car calculates:

No need: https://evkx.net/models/porsche/macan/macan_4/chargingcurve/

 

[Yves]

thank you @seabird !

and because the clarifying information is overlooked here so often, once again the information provided by @seabird. this answers all questions and thats how the car calculates:

No need: https://evkx.net/models/porsche/macan/macan_4/chargingcurve/

Hmmm I tried to charge, battery was on temp … 53% and saw 120 kw and it slowed to around 100 at 60% quite disapointed … tried another station charger capable of 350 and was not shared, same … the curve went drastically down, no idea how that comes … according to the chart I should have been at 175 to 150 …
Anyone else seen charge power being reduced lately?

 

[TomekGnomek]

What I can add to this discussion is that I frequently travel between cities 300 km apart with a fast Ionity 800V 350KW charger in the middle of my route and almost always charging sessions take longer then the estimate. Battery is always preconditioned to optimal temp with outside temps 10-20C and very often no other cars charging. Charging usually starts well above 200KW (250KW, 270KW) so the station is capable of providing this much power but the car quickly throttles charging speed (I think much more than the suggested curve) and I'm not talking about anything above 80% (which is really slow and above 90% it drops below the capabilities of AC home charger to 5-7KW).

The release notes to the newest software update mention something about a fix to calculating SoC which should improve charging performance so I must mean in some conditions it is less than optimal. I'm set to to this update in two weeks, will let you know.

 

[seabird]

If only evkx.net provided a model that estimated charge time based on starting battery temperature too.

It really doesn't make a difference. Any battery temp between 5 and 30C is only going to deviate by less than a minute. DC fast charging generates a tremendous amount of heat very rapidly.

If you're in some sort of Scandinavian or arctic town, then the only change in the model is still just going to be however long it takes the battery to warm up to above freezing, and then the actual charging starts along the same curve.

Hmmm I tried to charge, battery was on temp … 53% and saw 120 kw and it slowed to around 100 at 60% quite disapointed … tried another station charger capable of 350 and was not shared, same … the curve went drastically down, no idea how that comes … according to the chart I should have been at 175 to 150 …

120-130kW is the derated speed of a 350kW charger, just like 50-60kW is the derated speed of a 150kW charger. These speeds are indicative of a cooling or supply problem with the charging station, not the car.

The release notes to the newest software update mention something about a fix to calculating SoC which should improve charging performance so I must mean in some conditions it is less than optimal.

SoC calculations have almost nothing to do with charging performance. The only place they intersect is whether the car is accurately measuring the starting SoC (if it calculates 11% when you're only at 8%, it will take slightly longer to charge). There is no chance that the estimate can change charging times by more than a minute or two.

The Macan is not throttling you 50+kW below its curve. There's nothing that this car (or any other EV) does that causes charging performance to deviate from the programmed curve by that much without an active fault in the onboard charger. All slow charging is a result of the external station's limitations.

 

[macanchan]

Electrify America slows down significantly for everyone after 80%. Don't be one of those idiots charging past 80%. I have no problem telling people to get out of there once they are past 80%. Different story if there isn't a line of people. Take all the time you have.

It's EA that sets these parameters. If they didn't throttle the charging speed, we wouldn't have this problem.

 

[Yves]

2 derated stations one with a slow charging Mercedes on another charger, so not shared, doubtful … if that is the case 800v is a hoax …
I tried 2 different sites … both same speed and site as mentioned was almost empty, one other car at another charger capable…

 

[ColdCase]

Its only been a couple months and maybe a dozen fast charge sessions but from what I've observed, the PCM estimate is close. The guess seems to be closer when the battery is at optimum temperature and the ambient temperature is 50+ F when you plug in.

I have observed the charging rate unexpectantly changing (I assme the charger) and after a few seconds the PCM revising its completion guess. So If you are not observing the rate real time, it could seem like the original completion guess was way off.. It was, but because something unexpected happened, probably the charger.

Today, for example, the battery was pre-conditioned before plugging into a 350kW EA station with 40% charge. The PCM Indicated it was getting 175kW and would take 20 minutes to get to 85%. When the battery temperature exceeded the high level of the optimum range, the charging rate slowly dropped off to 140kW indicated but with the same estimated end time (1210). Then there was a sudden drop to 70kW. After maybe 5 seconds, the PCM recalculated the end time to 1220. A minute or two later, charging resumed at 140 kW and again the PCM revised its guess to 1211. The charging rate continued to slowly drop to 70 at around 80% , as one would expect. It reached 85% at 1211.

I think there are so many variables that the PCMs best guess can be way off when unanticipated things happen.

Does anyone notice that the car seems livelier (more responsive to small throttle changes) when the battery is at optimum temperature or higher?

 

[PrudentOcean]

Electrify America slows down significantly for everyone after 80%. Don't be one of those idiots charging past 80%. I have no problem telling people to get out of there once they are past 80%. Different story if there isn't a line of people. Take all the time you have.

It's EA that sets these parameters. If they didn't throttle the charging speed, we wouldn't have this problem.

It doesn’t make sense for EA to slow down the charging past 80%, it is in their best interest to get people in and out as quickly as possible and free up the charger. The cars slow down significantly at that point, but the EVSE doesn’t. That’s why EA has a 85% charging limit at some of their locations.

 

[ColdCase]

It doesn’t make sense for EA to slow down the charging past 80%,

Perhaps Porsche or EV slow down the chargers in general so we exceed the 30 minutes free time and squeeze some money out of us....

 

[seabird]

2 derated stations one with a slow charging Mercedes on another charger, so not shared, doubtful … if that is the case 800v is a hoax …
I tried 2 different sites … both same speed and site as mentioned was almost empty, one other car at another charger capable…

If you are at a 350kW station and you're getting ~120kW, that is the restricted output "safe" mode for the box, caused by any number of factors, such as:

• Cable cooling failure
• Temperature probe failure
• Transformer overheating
• Tripped supply breaker
• Transformer fault limiting output to 400V
• Station only supports 400V charging (max 135kW on the Macan)
• Individual unit is on a shared circuit with another car
• Too many cars charging at station
• Station power supply limitation due to inoperative equipment
• Power utility rate cap

Some of these conditions affect a single charging pedestal; power supply and transformer issues affect the entire facility. But if you see DCFC rates of 34kW, 50-60kW, or 120-130kW, those are due to equipment restrictions (or, specifically for ~130, the Macan doing the split-cell charging thing on 400V chargers).

 

[Yves]

If you are at a 350kW station and you're getting ~120kW, that is the restricted output "safe" mode for the box, caused by any number of factors, such as:

• Cable cooling failure
• Temperature probe failure
• Transformer overheating
• Tripped supply breaker
• Transformer fault limiting output to 400V
• Station only supports 400V charging (max 135kW on the Macan)
• Individual unit is on a shared circuit with another car
• Too many cars charging at station
• Station power supply limitation due to inoperative equipment
• Power utility rate cap

Some of these conditions affect a single charging pedestal; power supply and transformer issues affect the entire facility. But if you see DCFC rates of 34kW, 50-60kW, or 120-130kW, those are due to equipment restrictions (or, specifically for ~130, the Macan doing the split-cell charging thing on 400V chargers).

On the same station I could easily get 270kw 6 month’s ago, there was only one Mercedes so not that fast charging it was not hot and that station is very lightly occupied … both different stations are 800v so no bank charging.
I hope I’ll be able to test this week again as I need to take a long trip, was planning to charge to 100% to make round trip in one go, but now I will plan for a stop.

 

[TomekGnomek]

SoC calculations have almost nothing to do with charging performance. The only place they intersect is whether the car is accurately measuring the starting SoC (if it calculates 11% when you're only at 8%, it will take slightly longer to charge). There is no chance that the estimate can change charging times by more than a minute or two.

Overview of changes due to this software update:
(...)
High-voltage battery control unit (J1120) Robustness measure: Optimized battery capacity calculation to improve range, charging power and SoC display

 

[seabird]

Overview of changes due to this software update:
(...)
High-voltage battery control unit (J1120) Robustness measure: Optimized battery capacity calculation to improve range, charging power and SoC display

Exactly. SoC is a calculated value.

The error bars are not more than a single digit percentage. They're not changing the power curve by 50kW or adding 50 miles of range here.

 

[Hawk_Tuah]

I recently charged from 10% to 80% in 26 minutes at a 150 kW station

We’ll that’s interesting. That should be physically impossible since the macan has a 100kw/h battery and the maximum kWh you can charge at a 150kw charger in 26 is 64,95. kWh.

Does it mean that the Porsche only uses 92.8% of its battery?

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