Total measured useable battery capacity of 93.7 kWh

[Vim Schrotnock]

I had a very unique charging experience and I think it would be very interesting to see if others have some data that we can compare. I ran the car down to 2% (driving around my home for the last few %), let the car sit the next day, then charged at home to 100% using the Porsche charger. The data is shown below in the MyPorsche app. If the 91.8kWh delivered is correct, and represents 98% of the total battery capacity, this would mean 100% capacity would be 93.7kWh. A pretty high number for a 2020 car with 36,000 miles (and yes, 2/33 modules replaced).

Anyone else have this kind of data?

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[daveo4EV]

fast charging or slow charging - this makes sense from a point of view of kWh's delivered to the vehicile - with AC/DC conversion losses and other overhead - 91.8 kwh delivered to the vehicle's charging port could easily be only 82'ish kWh delivered as battery capacity due to losses in the charging process…

82.3-84.3 kWh "usable" is the target capacity according to porsche tech talks and general knowledge - with 10% overhead therefore a 0-100% charge coudl easily demand 92 kwh's from the EVSE to "land" that many kWh's of capacity into the battery for a given charging session.

 

[Scandinavian]

I agree with @daveo4EV above that the losses from the EVSE and into batter is about 10-12%.
I did a similar charging on my return home after a long Norwegian trip. On the cvice of you I ran it down to close to 10% and charged to 100%. I then got 86 kWh on the PMCC.

 

[Vim Schrotnock]

fast charging or slow charging - this makes sense from a point of view of kWh's delivered to the vehicile - with AC/DC conversion losses and other overhead - 91.8 kwh delivered to the vehicle's charging port could easily be only 82'ish kWh delivered as battery capacity due to losses in the charging process…

82.3-84.3 kWh "usable" is the target capacity according to porsche tech talks and general knowledge - with 10% overhead therefore a 0-100% charge coudl easily demand 92 kwh's from the EVSE to "land" that many kWh's of capacity into the battery for a given charging session.

Very good point. I hadn't figured on the probably significant energy losses in the cable (lots of heat). Reviewing some of my other OBD readings, I'm seeing 79.35kWh at 99.72% SOC.

 

[Murph7355]

Which section of the app should you see this data in? I've clicked on account, but don't see anything in there.

Is it only with a particular type of charger?

 

[WasserGKuehlt]

fast charging or slow charging - this makes sense from a point of view of kWh's delivered to the vehicile - with AC/DC conversion losses and other overhead - 91.8 kwh delivered to the vehicle's charging port could easily be only 82'ish kWh delivered as battery capacity due to losses in the charging process…

82.3-84.3 kWh "usable" is the target capacity according to porsche tech talks and general knowledge - with 10% overhead therefore a 0-100% charge coudl easily demand 92 kwh's from the EVSE to "land" that many kWh's of capacity into the battery for a given charging session.

This^. It appears that the charging session data available in the app is measured at the charger/EVSE - not as received by the car. (We had sort of a debate on this on the recent app thread, won't repeat the arguments here.) And indeed losses are about 10% (8.7kW at the car from 9.6kW out of the EVSE in my case -> 90.6%).

I could not find data on individual charging sessions with CarScanner, but I suspect with the right measurements/sampling we could reconstruct a car-side charging log.

 

[WasserGKuehlt]

Which section of the app should you see this data in? I've clicked on account, but don't see anything in there.

Is it only with a particular type of charger?

Yes, it appears to be available only with PMCC or the wall charger; PMC+ may show this too, but that one supports only powerline networking, and it's been iffy for me.

 

[Scandinavian]

I could not find data on individual charging sessions with CarScanner, but I suspect with the right measurements/sampling we could reconstruct a car-side charging log.

But when you use CarScanner, the car will need to be switched on. Then all PCM and ECU’s will be powered up even if you switch off the fan annd ventilation etc.
And that probably draws about 500 watts.

 

[f1eng]

Very good point. I hadn't figured on the probably significant energy losses in the cable (lots of heat). Reviewing some of my other OBD readings, I'm seeing 79.35kWh at 99.72% SOC.

I can measure AC power supplied and read charge rate on the car's display and the first is always about 500W more than the second.
It surprised me it is this much but I suppose it is losses in the in car AC-DC conversion and pump circulating the coolant.

 

[AndiL]

On AC charging there is hardly any cooling or warming necessary. All the electronics to do the charging do consume power obviously (Battery Management, On-Board-Charger, etc.). This can be up to 700W.

 

[Gru]

But when you use CarScanner, the car will need to be switched on.

That's what I also thought but it works when switched off.
I was able to get the full data set even when the car was switched off and locked while charging in a recent trip. Only one constraint : you have to leave your phone in the car....

 

[Vim Schrotnock]

Which section of the app should you see this data in? I've clicked on account, but don't see anything in there.

Is it only with a particular type of charger?

Go to the 'My Porsche' app and if you have the Porsche charger, you'll see a house icon with a plug. Click on his icon, and you'll see a list of recent 'charging processes', with a box saying 'Show charging history'. Click on this box and you can bring up your last 12 months of charging.

 

[R Benny Waered]

Likely mostly losses in the AC to DC converter in the car. Disappointed its so high as its around 10% but many agree to that figure.

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