Home charging software limitations

[Pozuelo]

I do, have a HEM, yet I do not use it for preferred time. My use case is special as I use it in daytime when if I have enough solar capacity or at night or weekends if I don’t. My important function is so that the the charger together with my domestic usage never exceed the 17,2 kw maximum draw from the supply with the electrical company. If I exceed it, there is a penalty which increases the price of the whole month’s invoice in an exponential manner ! By the way, yesterday was my record for solar production 194kwh from a total consumption of 283kwh. I did charge the Taycan from 40% to 85%, albeit at 11kw because I have 22kw available at home, but the 22kw option was removed by Porsche when they built mine.

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[daveo4EV]

Porsche's charging software user interface is:

1. dumb
2. overly complicated
3. lacks a simple "charge starting at this time to NN%"

you can kinda sorta of "fake" it by manipulating departure time but not really

the lack of a "start" charging "at this time" also has a problem:

with variable/split-load AMP rate chargers the charging time can vary - this will cause the Porsche software to "miscalculate" the "start" charging now time window because it can't predict the AMP rate variations during the charging session.​

I really wish porsche would add/modify at least two things to the charging software:

1. start charging @ time - alternative to pure departure time
   1. extra credit entering a "schedule" of peak/off-peak rate periods so it "knows" when it's cheap to charge
2. in car overide of AMPs so that I can dial down the amperage to accomodate various "flaky" chargers where pulling max amps can cause problems (both public and private chargers)

Porsche's charging software has a long ways to go to even match the simplicy and feature set of my $26k 2017 Chevy Bolt.

 

[W1NGE]

I do, have a HEM, yet I do not use it for preferred time. My use case is special as I use it in daytime when if I have enough solar capacity or at night or weekends if I don’t. My important function is so that the the charger together with my domestic usage never exceed the 17,2 kw maximum draw from the supply with the electrical company. If I exceed it, there is a penalty which increases the price of the whole month’s invoice in an exponential manner ! By the way, yesterday was my record for solar production 194kwh from a total consumption of 283kwh. I did charge the Taycan from 40% to 85%, albeit at 11kw because I have 22kw available at home, but the 22kw option was removed by Porsche when they built mine.

I see given the recent PCM announcement that 22kW retrofit is now back on the table as of yesterday.

 

[Pozuelo]

Available at the dealer for retrofit ? Or as an option on new cars ?

 

[W1NGE]

https://www.taycanforum.com/forum/t...fotainment-improvements-and-range-bump.11871/

The 22 kW onboard charger has now also recently become available for retrofitting1. Customers can combine this retrofit at their own expense with a workshop visit for the software update. With up to 22 kW of charging capacity, the more powerful variant charges the battery significantly faster. In Europe and North America, the retrofit also includes activation of the Plug & Charge function. This enables convenient charging and payment without a card or app. As soon as the charging cable is plugged in, the Taycan establishes encrypted communication with the Plug & Charge-compatible charging station. The charging and payment processes then start automatically.

 

[Pozuelo]

https://www.taycanforum.com/forum/t...fotainment-improvements-and-range-bump.11871/

The 22 kW onboard charger has now also recently become available for retrofitting1. Customers can combine this retrofit at their own expense with a workshop visit for the software update. With up to 22 kW of charging capacity, the more powerful variant charges the battery significantly faster. In Europe and North America, the retrofit also includes activation of the Plug & Charge function. This enables convenient charging and payment without a card or app. As soon as the charging cable is plugged in, the Taycan establishes encrypted communication with the Plug & Charge-compatible charging station. The charging and payment processes then start automatically.

Thanks. Just saw the announcement and called my dealer’s shop foreman to inquire. Will advise when I get a response.

 

[Shigura]

I posted this sometime back when I went through this same thing on my RWD. May help. Agree, its convoluted.
https://www.dropbox.com/s/u9p0hz429al54hg/Charge Timer and Profile Setup2.pdf?dl=0

 

[Shigura]

I have printed out your excellent work through of your settings. But before I try your solution can you confirm that charging ceases at the end of the cheaper window even if the target level of charge has not been reached.

 

[timc3]

Porsche's charging software user interface is:

1. dumb
2. overly complicated
3. lacks a simple "charge starting at this time to NN%"

you can kinda sorta of "fake" it by manipulating departure time but not really

the lack of a "start" charging "at this time" also has a problem:

with variable/split-load AMP rate chargers the charging time can vary - this will cause the Porsche software to "miscalculate" the "start" charging now time window because it can't predict the AMP rate variations during the charging session.​

I really wish porsche would add/modify at least two things to the charging software:

1. start charging @ time - alternative to pure departure time
   1. extra credit entering a "schedule" of peak/off-peak rate periods so it "knows" when it's cheap to charge
2. in car overide of AMPs so that I can dial down the amperage to accomodate various "flaky" chargers where pulling max amps can cause problems (both public and private chargers)

Porsche's charging software has a long ways to go to even match the simplicy and feature set of my $26k 2017 Chevy Bolt.

I tried telling Porsche's support the same thing, it was obvious that who was ever on the phone didn't use an electric car.

 

[AndiL]

The Porsche HEMS will do the following:

- % SoC defined in the Profile: no change, will provide enough energy to reach this % as fast as possible, ignoring any costs
- Timer % SoC Goal: will use the provided tariff data (setup in the Porsche HEMS UI) and make a most cost effective plan to reach the % goal with the lowest cost

It will not disallow charging outside of the desired times, as the % SoC is always the main target. There is no way with the PMCC or the Porsche HEMS to automatically restrict charging to a specific time only and never to charge outside of that time window.

 

[dflohr]

I have printed out your excellent work through of your settings. But before I try your solution can you confirm that charging ceases at the end of the cheaper window even if the target level of charge has not been reached.

Shigura, With that setup, my car has never charged outside of the charging window. HOWEVER, with our level 2 charger and our driving/charging pattern, we never run the battery down enough so that our 80% target could not be reached during the charging window. May try that however I'll bet that it would stop with the charging window having higher priority than the 80% target charge.

 

[JAGMAN]

Agree with the comment that the software onboard the car could be more intuitive. Take for example the General profile, "Minimum charge" is the chosen label to describe "Maximum charge." I do understand the nuances of how to work timers and profiles together thanks to threads like this. In the end it would be hard to add a maximum charge setting to clear up some of the confusion.

 

[DerekS]

@JimBob @DerekS
Timers don’t completely ignore preferred times, but they are prioritized such that they allow charging outside of the preferred time if required.

For example: on Derek’s setup of a a timer at 85% at 6am with preferred times between 8pm and 3pm using a 9.6 kW EVSE, the timer can always charge within the preferred time.

However, if we change the preferred times to between 2am and 6am, it will start before the preferred times if plugged in below approximately 40%.

But preferred times aren’t completely ignored either. If we shift to 10pm to 2am, it will try to utilize that time.

And if we plug in with a higher SOC, it may reach the target within the preferred times, although note that it delays the start time as late as possible within the preferred time (added in orange)

This is a great explanation, thanks for taking the time to post it!
I now see what you mean, timers might cause "violation" of the time window, depending on when that window is and charging needs to be ready by the timer time.

 

[JimBob]

@Jhenson29
Referring to your Charging Calculator.

This is the interesting case that shows the Timer had at least some smarts as it stops and restarts.

Can you confirm if this is what happens in the real world along with how the calculator shows it?

 

[Jhenson29]

@Jhenson29
Referring to your Charging Calculator.

This is the interesting case that shows the Timer had at least some smarts as it stops and restarts.
Can you confirm if this is what happens in the real world along with how the calculator shows it?

Yes. I’ve done lots of testing on the operation numerous times to confirm consistency so I’m relatively confident in these calculations. Or at least the general logic behind them. Exact start times may deviate just slightly.

However, Porsche could also update it at anytime through a non-existent OTA. ?

And, of course, if anyone disagrees or has a correction, I’ll be happy to recheck if provided some settings and observed outcome.

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