PMCC lost charging kW

LovinTaycan

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I keep my car at 85% but ever so often I drain it down to 20% and back up to 100%.

Today, eveything was going along just fine until the last hour my PMCC lost all ability to charge at the proper kW.

Has this happened to anyone, or do I need a new PMCC.

You can see the loss of kW at the end of the charging cycle. It never did recover.

Porsche Taycan PMCC lost charging kW Screen Shot 2021-04-26 at 3.24.41 AM
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W1NGE

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Not seen that before but to be honest I don’t have a lot of faith in the data and how it is displayed in the chart.

I notice you have missing data points (Start, End etc) which I suffer from too. My biggest bug bear is the time display on the axis - it never corresponds to UK time. Also the charging duration is misleading as the clock starts once you connect the charger - not when the charging starts.

There could be a genuine reason for the kW tail off or it is more buggy software.
 

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You can see the loss of kW at the end of the charging cycle. It never did recover.
You seem to have used about 82 kW from the Grid? You did not state what charge level you had in the car at the end?

Perhaps you are at 100% and the charger tops up the battery in that manner to reach 100%? During the rest of the time it looks fine. So is there really a problem?
 

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I keep my car at 85% but ever so often I drain it down to 20% and back up to 100%.

Today, eveything was going along just fine until the last hour my PMCC lost all ability to charge at the proper kW.

Has this happened to anyone, or do I need a new PMCC.

You can see the loss of kW at the end of the charging cycle. It never did recover.

Screen Shot 2021-04-26 at 3.24.41 AM.png
I think that after reaching 100% charge a little after 2AM, the rest of the charging process has only added 1-2 kWh in the last hour. My old Tesla ModelS 85kW behaves similarly at a 100% charge. After reaching 100%, the individual cells in the battery are balanced.
 

andrewket

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Don’t have my Taycan yet but if it’s anything like Tesla this is 100% normal for Li-ion batteries. At very high SOC the charge rate is reduced. Tesla will get down to <1kW at 99.5%.
 


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LovinTaycan

LovinTaycan

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I think that after reaching 100% charge a little after 2AM, the rest of the charging process has only added 1-2 kWh in the last hour. My old Tesla ModelS 85kW behaves similarly at a 100% charge. After reaching 100%, the individual cells in the battery are balanced.
The problem is that it did not reach 100% and kept going at the reduced load for several hours until it got to 100%. That can't be right.

Porsche Taycan PMCC lost charging kW Screen Shot 2021-04-26 at 7.01.59 AM
 

andrewket

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The problem is that it did not reach 100% and kept going at the reduced load for several hours until it got to 100%. That can't be right.

Screen Shot 2021-04-26 at 7.01.59 AM.png
It can. Again, apologies for the constant comparison to Tesla, but that’s the majority of my experience. Tesla balances the cells and finds the max voltage with a 100% charge. It can take hours with less than a 1A draw to complete.

It’s a common misconception that balancing only occurs at 100%. This is not true; balancing occurs all the time via bleed resistors.
 

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The problem is that it did not reach 100% and kept going at the reduced load for several hours until it got to 100%. That can't be right.

Screen Shot 2021-04-26 at 7.01.59 AM.png
I have a hard time understanding the connection between the first data sheet from the "Porsche Charging Service" and the latest image you have attached.
To receive data on charging in "My Porsche", you must have a completed charging process. Ie. that the charging socket must be disconnected from the car in order to send data to "My Porsche".

According to data from the first image, a charge has been made from 6.11 PM-3.15 AM. during charging, the PMCC has sent 82.4 kWt to the car.
With a charge loss of 5-10%, this means that the battery in the car has received 74-78 kWt. With a net battery capacity of approx. 86 kWt this corresponds to a charge from approx. 10% to 100%.
When reading the curve for the current, you can see that from 6.11 PM to approx. 2.15 AM, the current has been 10 kW. There are thus up to approx. 2.15 AM been added approx. 80 kWt for the battery. The battery is thus fully charged unless the SOC has been below 10% when connected.
I therefore believe that the charging curve for the charging process is correct.

The latest image shows a charge from 3.18 AM to 7.01 AM. The picture also shows a waiting exhaust time. (Blue battery) The picture shows that 3.27 kWt has been added to the car during this period. If the temperature is low in connection with an outlet timer, power can be supplied to heat the battery.

On the other hand, it makes no sense to immediately after adding 82.4 kWt to the battery that it then shows an almost empty battery in the blue battery symbol. Could the latest image be from another date?
 


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LovinTaycan

LovinTaycan

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It can. Again, apologies for the constant comparison to Tesla, but that’s the majority of my experience. Tesla balances the cells and finds the max voltage with a 100% charge. It can take hours with less than a 1A draw to complete.

It’s a common misconception that balancing only occurs at 100%. This is not true; balancing occurs all the time via bleed resistors.
I guess the problem I’m having with this, is that I’ve had 2 Model S Teslas, both with 19.8 kW charging, and I never had this occur.

Also, I had the 2020 Taycan, and it never occurred, so I am at a quandary as to why it’s occurring now.
 
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LovinTaycan

LovinTaycan

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I have a hard time understanding the connection between the first data sheet from the "Porsche Charging Service" and the latest image you have attached.
To receive data on charging in "My Porsche", you must have a completed charging process. Ie. that the charging socket must be disconnected from the car in order to send data to "My Porsche".

According to data from the first image, a charge has been made from 6.11 PM-3.15 AM. during charging, the PMCC has sent 82.4 kWt to the car.
With a charge loss of 5-10%, this means that the battery in the car has received 74-78 kWt. With a net battery capacity of approx. 86 kWt this corresponds to a charge from approx. 10% to 100%.
When reading the curve for the current, you can see that from 6.11 PM to approx. 2.15 AM, the current has been 10 kW. There are thus up to approx. 2.15 AM been added approx. 80 kWt for the battery. The battery is thus fully charged unless the SOC has been below 10% when connected.
I therefore believe that the charging curve for the charging process is correct.

The latest image shows a charge from 3.18 AM to 7.01 AM. The picture also shows a waiting exhaust time. (Blue battery) The picture shows that 3.27 kWt has been added to the car during this period. If the temperature is low in connection with an outlet timer, power can be supplied to heat the battery.

On the other hand, it makes no sense to immediately after adding 82.4 kWt to the battery that it then shows an almost empty battery in the blue battery symbol. Could the latest image be from another date?
Thanks for your thoughts.

When I looked at the car at 3:15 AM the charge was not 100%, but 98%. When I started the charge, the battery was very low in the teens.

I saw that it was not giving the full 9.7 kW so I disconnected the charger because I thought if I started over, maybe it would come back to the 9.7 kW charging. As you can see, it never really came back to the 9.7 and when I disconnected it some three hours later, it had finally made it to 100%.

I have spoken to the dealer who has spoken to Atlanta. They say the last 10% can vary, but the times periods I experienced were too excessive and didn't appear to be within the norm. They asked me to try again, but I need to wait to get the battery down into the teens again.

Hope this helps.
 
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LovinTaycan

LovinTaycan

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My internal CPU temperature is getting as high as 183 degrees and the PMCC is very hot to the touch. Is this normal? What is a safe CPU temperature range and is there a internal shutdown mechanism if it gets too hot?

Porsche Taycan PMCC lost charging kW Screen Shot 2021-04-28 at 10.33.42 PM
 
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jimithing

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My internal CPU temperature is getting as high as 183 degrees and the PMCC is very hot to the touch. Is this normal? What is a safe CPU temperature range and is there a internal shutdown mechanism if it gets too hot?

Screen Shot 2021-04-28 at 10.33.42 PM.png
That CPU temp isn't all that high (84 degrees Celsius) but I'm wondering what's going on that has the persistent space up to 92% full. Like anything that plugs into a wall, unplug it for a while & try again. Could be a transient condition. If it happens twice, thrill be more motivated to look into it.
 
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LovinTaycan

LovinTaycan

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That CPU temp isn't all that high (84 degrees Celsius) but I'm wondering what's going on that has the persistent space up to 92% full. Like anything that plugs into a wall, unplug it for a while & try again. Could be a transient condition. If it happens twice, thrill be more motivated to look into it.
You have it backwards, the persistent space is 92% free.

Also, it all went downhill from my last post.

Porsche Taycan PMCC lost charging kW Error Messa
Porsche Taycan PMCC lost charging kW Some 3 hours later
 

W1NGE

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Oh dear not good. Could be your AC charger port has an issue. Mine failed 2 months back and was replaced. Have you tried the other port?

My cpu is around 40C and sleeps most of the time. Not sure what it reaches when charging.
 
 




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