Dear Porsche: Please let us set a DC fast charging limit in %

j.w.s

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Imagine your battery charge level at say 40%, and you want to top up to 75% for the next leg of your journey. So you plug in to a 150kw or 350kw DC fast charger and head off to grab some lunch or do a bit of shopping.

Returning a bit later, the battery is at 95% - far higher than you intended. As commonly happens, the car was ready to go before you were.

It would be very useful - and just a software change - to let us set a charge limit when DC fast charging, just like we do when AC charging at home. Mercedes does it, Tesla does it, as do others. Dear Porsche: Please add this feature!! And then have the app ping me when I get close to my desired charge level.

Here's the Tesla version, showing a 90% charge limit set on a Model Y and being used at a Supercharger station:
Porsche Taycan Dear Porsche: Please let us set a DC fast charging limit in % 1702899359195
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whitex

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If you only need 75%, please come move your car once you reach it and allow others to use the charger. Tesla implemented idle charges, $1-$2 per minute if your car is plugged in to the DC charger but not charging. Are you sure you'd prefer that? Using your example, the way it is, if your are juiced up higher than intended, you will take less time on your next DCFC stop on your journey, freeing it for others to use. If you get your desired 75% limit, you might pay $40 in idle fees, but you unnecessary occupied a plug someone else might be waiting for, and the next charger you will not have the extra charge to charger shorter.
 
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j.w.s

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If you only need 75%, please come move your car once you reach it and allow others to use the charger. Tesla implemented idle charges, $1-$2 per minute if your car is plugged in to the DC charger but not charging. Are you sure you'd prefer that? Using your example, the way it is, if your are juiced up higher than intended, you will take less time on your next DCFC stop on your journey, freeing it for others to use. If you get your desired 75% limit, you might pay $40 in idle fees, but you unnecessary occupied a plug someone else might be waiting for, and the next charger you will not have the extra charge to charger shorter.
My request is to Porsche, asking them to match what is a common feature of other EVs so that I can treat my battery as gently as possible, when possible. If the public charge vendors want to implement idle fees, I'm good with that. Tesla, for example, charges half a dollar/euro per minute, or double that if a given facility is more than half full. Seems entirely fair.
 

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Imagine your battery charge level at say 40%, and you want to top up to 75% for the next leg of your journey. So you plug in to a 150kw or 350kw DC fast charger and head off to grab some lunch or do a bit of shopping.
No wonder there are so many occupied chargers then. Quite irresponsible to want to charge from 40% to 75% at a 350 kW charger and then head for lunch. It would perhaps have taken you 10 minutes to wait in the car and then move on. Given the slowdown after 80% SoC it takes a lot of time to go to 95%.
 


whitex

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My request is to Porsche, asking them to match what is a common feature of other EVs so that I can treat my battery as gently as possible, when possible. If the public charge vendors want to implement idle fees, I'm good with that. Tesla, for example, charges half a dollar/euro per minute, or double that if a given facility is more than half full. Seems entirely fair.
You can treat your battery gently by enabling battery saver mode, which will limit max charge rate to what is considered gentle by Porsche. If you are on a trip, charging to 95% is not going to hurt your battery, not void your warranty. The problem with implementing idle fees for Taycans is the unreliability of the Taycan app. Tesla will reliably inform you when you are approaching the set limit. Porsche app is not that reliable and they don't want to take on the liability to pay your idle charges just because their app failed to notify you. I personally like the Tesla solution, I just don't think it's practical for CCS cars yet. So the only practical solution for CCS today is to charge people for the additional charge they don't want (to "baby" their batteries) or don't want to pay for - it's an idle fee substitute. It seems to work on you, as you now pay attention to when to go unplug your car.

PS> Running your battery at lower SoC (State of Charge) on trips is actually not treating it gently, it's the opposite. If you drove a long journey charging 50-95% at every stop, you'd wear your battery less than if you charged it 10%-55% (same increment, but starting lower), though running it lower will speed up your trip (at the cost of more battery wear). This is because at lower SoC your battery will accept a higher rate of charge, which has been shown to be a primary cause of battery wear (together with high rate of discharge) - way more than temporarily charging above 80%. 50-95% will take longer, but will save your battery. This is also why Porsche "Battery Saver" mode limits the maximum DC charge rate, not the maximum SoC.
 
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j.w.s

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Oh boy this got a bit off topic rather quickly. There are plenty of annoying people clogging up 350kw chargers with cars pulling 40kw, people charging oh so slowly to 100%, etc. That's not me. And yes I do have battery care mode enabled. And I have built lithium packs and programmed battery management systems, so I fully understand the details of batteries and battery care, so I know that deep discharges are not good, etc.
This is an entirely different topic. I want control over my battery like you get in most EVs, and like we get when slow charging - the ability to set a charge limit.
 

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"WHITEX@
If you drove a long journey charging 50-95% at every stop, you'd wear your battery less than if you charged it 10%-55% (same increment, but starting lower), though running it lower will speed up your trip (at the cost of more battery wear). This is because at lower SoC your battery will accept a higher rate of charge, which has been shown to be a primary cause of battery wear (together with high rate of discharge)"

[/QUOTE]
It is not proven I mean not true. Charging from higher SOC generates significantly more heat, that is why charging speed is limited in the ratio of higher SOC.
Charging from lower SOC generates less heat so BMS allows higher charging speed.
Heat is the main issue of degradation, that is kept in balance by the BMS according to the above.
Charging 10-55% causes similar or less wear than 50-95% maybe little bit less as charging above 80-85% hurts the battery more if not pick up immediately.
Additionally the benefit of charging from lower SOC is less charging time.
It is in line with that, Porsche Charging Planner implements as low possible starting SOC as possible when planning the route.
 
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arijaycomet

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Totally agree with @j.w.s here--- better to provide the UX maximum granular control. It is always a better option for consumers. Though at the same time, people are sadly idiots and don't understand. But hey if DC defaults to 100% then so be it (same as now) but those of us who want to change it can.

Another great reason to have the ability to set DC charging top % is that you can quickly and easily see the time. I don't recall what the native nav does on Porsche, but in the AAOS/Google setup on the Volvo/Polestar, it would tell you "charge to 65% to make it to next stop" (as you arrived at a charger) -- so it'd be nice to set that slider so you can also visually see how many estimated minutes until you hit target --
 

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Imagine your battery charge level at say 40%, and you want to top up to 75% for the next leg of your journey. So you plug in to a 150kw or 350kw DC fast charger and head off to grab some lunch or do a bit of shopping.

Returning a bit later, the battery is at 95% - far higher than you intended. As commonly happens, the car was ready to go before you were.

It would be very useful - and just a software change - to let us set a charge limit when DC fast charging, just like we do when AC charging at home. Mercedes does it, Tesla does it, as do others. Dear Porsche: Please add this feature!!
Although I have no Mercedes, but have Tesla (M3P) and BMW (i4) next to the Taycan, but non of the mentioned cars allow to limit the DC charging power, only on AC.
 

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Although I have no Mercedes, but have Tesla (M3P) and BMW (i4) next to the Taycan, but non of the mentioned cars allow to limit the DC charging power, only on AC.
That is peculiar. My M3P can set the DC charge to whatever % I want and stop at that. The Tesla app will also notify me when the charge level is nearly achieved and warn about idle fees. In Tesla I just set one charge level and that is valid for both AC and DC charging.
 

Bognar67

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That is peculiar. My M3P can set the DC charge to whatever % I want and stop at that. The Tesla app will also notify me when the charge level is nearly achieved and warn about idle fees. In Tesla I just set one charge level and that is valid for both AC and DC charging.
Yes it is clear with me. I thought we are talking about to limit the charging power on DC I mean to set up max charging power 100kW or 80kw etc. similar as we are able to limit it on AC from 6A to 32A.
It was my misunderstanding, thanks to clarify. Using DC only on road trips when I let to work the Charging Planner, so did not recognized up to now it is not adjustable, I mean the max charging % on a scale.
Anyway Taycan also send a push message when the requested charging % is achieved (using Charging Planner) and can decide to stop the charging process from the app or let it charge further.
In this case Taycan needs a little bit more attention on DC without Charging Planner, opening the app time to time controlling the actual charging % and stop it manually when achieves the requested SOC%.

All together the nicest way is go away immediately from the charger when not charging. Suppliers applying idle fees to achieve this, but i4 allows a "trick".'Unlock the charging cable at the end of the charging process' feature results technically and visually plugged in charging cable that can be unattached at the end of the charging session. The result is showing the charger free, cable is usable but the car is still there so blocking the place without paying idle fee. Not 'gut' in my opinion although can be useful in some limited cases.
 
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The Audi e-tron (SUV, not GT)that I rented had the ability to set a dc charge limit. I set it to 85% and the car stopped charging at 85% when connected to a DC charger. I don’t wander away from my car for very long when DC charging so I don’t have a need for this feature but it worked fine on that Audi.
 
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Bognar67

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The Audi e-ton (SUV, not GT)that I rented had the ability to set a dc charge limit. I set it to 85% and the car stopped charging at 85% when connected to a DC charger. I don’t wander away from my car for very long when DC charging so I don’t have a need for this feature but it worked fine on that Audi.
Yes it is not essential but could be nice to have it on the Taycan as well.
 

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That is peculiar. My M3P can set the DC charge to whatever % I want and stop at that. The Tesla app will also notify me when the charge level is nearly achieved and warn about idle fees. In Tesla I just set one charge level and that is valid for both AC and DC charging.
there is a difference between euro L2 DC charging and L3 charging. I am willing to bet that you cannot set a time when using an L3 charger.
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