Warning about using range mode, in hot weather, after DC charging 150kW+

[Hirschaj]

I was reading the “charging” section of the manual and came across this interesting bit of information. It’s probably nothing major but I found it interesting and will try to remember this scenario and avoid it when possible. See screenshot for details.

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[Jhenson29]

I think I’ve read that before and it seems silly. Why would they leave that control up to the user? If the battery needs cooling….f*cking cool it. Who cares if the car is in range mode??‍

 

[Hirschaj]

I think I’ve read that before and it seems silly. Why would they leave that control up to the user? If the battery needs cooling….f*cking cool it. Who cares if the car is in range mode??‍

I agree, but yet it’s right there in the manual. Not sure what they are thinking. Maybe excessive CYA.

 

[whitex]

As @Jhenson29 said, this should have been handled by software. Either completely transparently, or via some message informing the user that Range mode is not available until the battery cools off.

It sounds like Porsche is using the manual as software release notes and rather than fix issues they find, they "rel-note" them. "Don't use range mode after DC charging when hot or the battery may overheat", "Don't charge over 6KW when using a single phase with 3 phase charger or your charge may damage itself", "Don't press buttons X, Y, then Z in sequence during is a full moon as it may active a self destruct sequence".

I think this is a very clear example of how traditional automakers are not prepared for complex, software defined cars. The process to fix issues in software is so involved and takes so long, it's quicker to amend the user manual. I think they are actually abusing the fact that the user manual is online, so they are patching the manual often, rather than software. I suspect one of two things will happen in the future, either:

1. they will get some stable software, then avoid changing it at all cost, therefore slowing innovation
2. they will finally figure out a model where they can quickly deliver important fixes and workarounds, while new features and other improvements can follow the standard slow release schedule.

I hope #2 will happen. Many OTA patch releases with only bug fixes and WAR's, and annual feature releases to give them time to properly validate. Tesla uses continuous integration model, many OTA releases of bug fixes, workarounds, AND new features. While this works great in a lab, or a test fleet, I'm not a big fan of that model for regular consumers. At least they introduced an option in the car where the customer can decide if they want the bleeding edge, or only releases somewhat tested (on other customers).

One last thing, the above from the OP also implies you should not use Range mode after tracking the car (or driving spiritedly) when it's hot outside.

 

[Jhenson29]

It sounds like Porsche is using the manual as software release notes and rather than fix issues they find,

It is a (frankly) bizarre issue. I can’t imagine a system function like this being under user control. I realize it’s not just fully under user control, but the fact that a user control can cause detriment is…less than correct.

It’s like making perspiration voluntary.

“Did you hear about Bob? Sad. He went for a run and turned sweating off to impress a girl. Real shame.”

No offense to anyone with anhidrosis.

 

[whitex]

It is a (frankly) bizarre issue. I can’t imagine a system function like this being under user control. I realize it’s not just fully under user control, but the fact that a user control can cause detriment is…less than correct.

It’s like making perspiration voluntary.

“Did you hear about Bob? Sad. He went for a run and turned sweating off to impress a girl. Real shame.”

No offense to anyone with anhidrosis.

Yep, hence evolution eliminated Bob's kind. Hopefully this won't happen to Porsche.

 

[Jhenson29]

I suspect one of two things will happen in the future, either:

1. they will get some stable software, then avoid changing it at all cost, therefore slowing innovation
2. they will finally figure out a model where they can quickly deliver important fixes and workarounds, while new features and other improvements can follow the standard slow release schedule.

Assuming this is the case, it may be best to get to #1 in the interim while they work on #2.

 

[nickmdp]

I interpret the initial statement of "The following measures can be taken to reduce battery ageing and wear" as effectively just telling people that taking those options might reduce wear by some margin, with obviously the battery warranty still applying. I mean seriously, avoiding parking in temps above 86 F? I'd be shocked if that were even possible in any of the markets where the Taycan is sold unless you somehow travel exclusively to climate controlled garages.

 

[whitex]

Assuming this is the case, it may be best to get to #1 in the interim while they work on #2.

I'm not so sure #1 is the best. The reason for that is that once a company gets to #1, they may not see much incentive to get to #2. Rapid bug fixes are needed more at the beginning of the new feature release, than later (though still needed if for nothing more than security patches).

I was once hired to help a company stuck in #1 type situation. Took us 2 years to reorg engineering, change processes, add continuous integration and automated testing/validation. After that 2 years, we had a new generation of the software product, increased revenue, we were at #2. Then the guy who hired me, who was brought in just before me to do this, moved on to a new opportunity. Old guard took over and reverted right back to #1 within one quarter. It took less than a month before they dismantled the automated testing/validation team completely - no need to write or run automates tests on a code which is not changing, right? I left shortly after that. It's been over a decade since. Last I checked, they've been acquired since but today are still selling the same product we made back then - making money from licensing and some NRE for customizations (essentially just milking the old tech without any innovation). *sigh*

 

[f1eng]

I mean seriously, avoiding parking in temps above 86 F? I'd be shocked if that were even possible in any of the markets where the Taycan is sold

I'd be surprised if it gets above 30C often in most of the coastal (within 75 miles) of northern Europe, which is a big part of the market.
Certainly not often here.

 

[rs38]

I assume it's an recommendation like the "do not charge more than 85% daily".

Of course the car will cool the battery even in range mode once some severe temps are exceeded, but there will be a temp-window, which is considered as not optimal and could cause some aging. And they write it down with obviously no legal effect but lacking experience how HV batteries will be in 8 years.

 

[whitex]

I assume it's an recommendation like the "do not charge more than 85% daily".

Of course the car will cool the battery even in range mode once some severe temps are exceeded, but there will be a temp-window, which is considered as not optimal and could cause some aging. And they write it down with obviously no legal effect but lacking experience how HV batteries will be in 8 years.

Range mode moves the max acceptable battery temp by 3-4C.
https://www.taycanforum.com/forum/t...-normal-sport-and-sport-plus.9881/post-142234
If what you're saying is correct, that means any time you drive in Range Mode you risk potential additional aging, since the battery temp could always get up there. So for example driving through mountains in Range mode just as bad (uphill large power draw, downhill recuperation - both heat up the battery).

 

[ciaranob]

I'd be surprised if it gets above 30C often in most of the coastal (within 75 miles) of northern Europe, which is a big part of the market.
Certainly not often here.

Well of the 41K odd Taycan's sold globally in 2021, roughy 9400 were sold in the US where such temps are more than common in over 2/3 of the country - so as it effects a minimum of ca. 1 in 5 Taycan's sold in the US (alone i.e. actual total should include all sold in middle eastern, Austral-asian S. American and other similarly intensely hot climate markets), then such high temps are most definitely relevant to a significant percentage of these cars. Reality is prob over 40% of all Taycan's sold will have to endure mid-80's and higher temps for sustained periods.

 

[f1eng]

so as it effects a minimum of ca. 1 in 5 Taycan's sold

So yes, stating it will be impossible to find in the majority of Porsche’s market is ignorant, as your data demonstrates.

 

[TXAG]

Thanks for the info - it matters for us here in Arizona USA. You'd think Porsche's software could make battery cooling in Range mode dependent on ambient temperature, but then it wouldn't be Range mode I guess.

EDIT: here's the weather forecast for where I live - at least it'll be a dry heat!

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