Locked out - another 12v saga

[daveo4EV]

I wonder if putting the car into privacy mode could prevent these issues at all. I'm about to leave my car sit for 8 days and I'd rather not have to deal with anything like this.

I think this has merit - it will certainly rule out any 12V drain issue associated with remote access - but it's not clear that is the only thing causing these problems - I think it won't hurt, but since it's a random software fault this by no means assures you won't encounter this problem - really there is nothing you can do to prevent this from occuring - like _ANY_ vehicle if your 12V starter power system is offline for any reason - you'll need to "boost" the vehicle to wake it back up…as long as we have 12V batteries involved to start a car - we will have this potential problem - there is NO way around it given current industry standard designs for EV or non-EV vehicle…

also there are actual problems sometime with 12V batteries simply being "bad" and no longer working as a battery - solution there is to replace the actual failed 12V battery - but it will present as a 12V battery drain problem…

there is no way to avoid this problem - pure and simple - and at the moment there is no indication that Taycan has a systemic problem in this space, and statistically it appears Taycan is no worse in this space than any existing ICE or non-ICE vehicle in terms of actual reliability.

expectations that this can never happen to you is unreasonable for any vehicle - Taycan included.

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[02bluesuperroo]

I think this has merit - it will certainly rule out any 12V drain issue associated with remote access - but it's not clear that is the only thing causing these problems - I think it won't hurt, but since it's a random software fault this by no means assures you won't encounter this problem - really there is nothing you can do to prevent this from occuring - like _ANY_ vehicle if your 12V starter power system is offline for any reason - you'll need to "boost" the vehicle to wake it back up…as long as we have 12V batteries involved to start a car - we will have this potential problem - there is NO way around it given current industry standard designs for EV or non-EV vehicle…

also there are actual problems sometime with 12V batteries simply being "bad" and no longer working as a battery - solution there is to replace the actual failed 12V battery - but it will present as a 12V battery drain problem…

there is no way to avoid this problem - pure and simple - and at the moment there is no indication that Taycan has a systemic problem in this space, and statistically it appears Taycan is no worse in this space than any existing ICE or non-ICE vehicle in terms of actual reliability.

expectations that this can never happen to you is unreasonable for any vehicle - Taycan included.

I agree with you in premise but 2 weeks is not long enough for a normal condition 12v lead-acid battery to lose charge beyond was is needed to start a car, much less unlock it.

It's really not a very good idea at all to have a random tow truck driver applying a 12v power source to your car's fuse box either. If something bad happens, who is going to be responsible?

 

[daveo4EV]

it's interersting to NOTE the original problem was in my opinion deeply embarrassing

it is not news that a 12V battery can be drained

the ORIGINAL problem was that the Taycan's 12V battery could be drained and drop offline WHILE THE VEHICLE WAS CHARGING AND PLUGGED INTO AN EXTERNAL AC POWER SOURCE - the car would die while BEING CHARGED!!!

that is like dying of de-hydration while swimming in a crystal clear fresh water lake!!

Porsche has since fixed this problem by all evidence and what we are left with are infrequent run of the mill 12V drain issues that can occur on most any vehicle, but nothing that rises to the level of the original problem of the Taycan dying while being plugged into an EVSE providing ample external power.

again in my opinion

• the original problem no longer occurs with any meaningful frequency - porsche seems to have fixed it
• can 12V drain issues still occur? yes. it was never an expectation this type of problem can be 100% eliminated.
• are these problem's fequency statistically meaningful vs. other historical norms for the industry - I don't believe they are. I see no data that indicates Taycan is less reliable than say a Panamera or Cayenne or any other ICE vehicle in this regard to this issue (all of which behave similarly with a drained 12V)
• can you 100% avoid this from occuring? no.
• is there anything you as the vehicle user can do to avoid these problems? probably not - the problem is a software bug and has nothing to do with how you are using the vehicle.
• is a 12V trickle charger necessary? not in my opinion, but hey if it makes you happy have at it.
• will a 12V tickle charger avoid this problem? not in my opinion - because once the Taycan is experiencing a high drain software bug, the power demands are too great for the trickle charger
• is using a 12V booster a problem? maybe, but so far I think it's more CYA than actual problem if used quickly and smartly - but if you don't want to use a booster don't use one.

it's not perfect , it never will be, the level of occurrence is no more frequent than any vehicle you've ever owned.

 

[daveo4EV]

It's really not a very good idea at all to have a random tow truck driver applying a 12v power source to your car's fuse box either. If something bad happens, who is going to be responsible?

while I agree with you in theory - this is the documented factory Porsche recovery process for a dead 12V/drained 12V battery on all of their vehicles - and 12V DC power is 12V DC power - there is no magic here.

once the car's 12V power system is offline (dead or tripped relay) the _ONLY_ mechanism to recover the vehicle is to provide a 12V external power source - end of story. And in the case of the Taycan lacking a manual fruck release - the ONLY way to access the approved power-supply access posts is to apply 12V power to a particular jumper-point in the fuse panel of the driver's foot well

THIS IS PORSCHE'S DOCUMENTED PROCESS TO RECOVERY THE VEHICLE - I see no alternatives.

so what are you suggesting is a better method?

1. dead 12V system - vehicle un responsive
2. manually open the vehicle's driver's door using the physical key
3. find the correct "fuse" connection in the driver's footwell for "power"
4. provide 12V power to this fuse connection point
5. use the vehicle FOB to open the frunk
6. dis-connect the 12V power source from driver's foot well
7. find the 12V "jumping" posts in the frunk
8. provide sufficient 12V power to these posts to "power" the vehicle systems
9. Taycan will "wakeup" and then recovery itself
10. disconnect external 12V power source.

the steps outlined above _ARE_ porsche's procedures
there is no alternative
it is highly unlikely your 12V power source can cause any problems if used correctly and briefly
this isn't rocket science
any latent problems after this procedure would be impossible to prove/deny/claim were caused by following porsche's proceedures or someone used an "incorrect" external 12V DC power source, for what ever that could mean…

it's really quite simple folks -you'd lap top's battery has died, you need to plug it into a power supply to wake it up…

in this Case the Taycan is a glorified lap top with a dead battery - plug it into the wall and it will wake up.

 

[daveo4EV]

this problem was more common prior to the latest updates (circa 2021) - I never expect Porsche to eliminate these problems that's impossible - just make them less frequent. My personal experience post update is that the 12V problems are far fewer and far between but still possible (as this post indicates). The recovery procedures are the same regardless of why your 12V battery is "offline", you simply need to provide power to the vehicle via the 12V jumping post in the frunk and the vehicle will cover itself…

the reason as to why the 12V drains itself are elusive and most likely software related to systems being allowed to run that should be "asleep" - this will get better over time as Porsche fixes more software bugs but the core problem can never be 100% fixed, there will always be corner cases where the software system can mistakenly keep the vehicle's systems "awake" and therefore place demands on the 12V system - causing a drain to low voltage which when reached will cut-off the 12V battery…

I am highly dubious of any 12V trickle charger mattering here for the following reasons:

• if there are no Taycan software faults the 12V tickle charger is un-necessary
• if there is a software fault keeping Taycan systems awake and draining power the power drain of Taycan systems will greatly exceed the 12V trickle charger's abilities and therefore still drain the 12V battery until it trips "offline"
  • once the 12V battery has dropped "offline" the trickle charger can not bypass the relay that has tripped and the 12V battery is effectively disconnected - therefore no power will ever reach the 12V once it's in this condition.
    • you must provide sufficient 12V power to the jumper posts to wake up/power the main computer in the Taycan for it to be alive and and reset the 12V relay
  • the fact that a 12V trickle charger is insufficient is trivally demonstarted by the fact that once the Taycan is in this state a 12V trickle charger like the CTEK doesn't provide enough power to "wake up" the Taycan's main computer
  • 12V trickle charger is nearly pointless for EV given my reasons above
• any 12V "booster" is sufficent to wake up the Taycan - and the only method other than an actual 12V battery for recovering the vehicle
  • there is _NO_ issue with lead-acid vs. liOn booster and what not - 12V power is 12V power is 12V power - and properly used the booster is only involved for 90 seconds or less…once the main computer has woken up the Taycan will recover itself - and you disconnect the 12V booster as once the vehicle is "alive" it is no longer necessary.
• The issue as to 12V boosters and the risk of using them is _NOT_ to the Taycan's systems, it is to the booster - as when the Taycan wakes and begins charging the vehicle's 12V battery that power will also flow "into" the 12V booster - potentially overwhelming the booster - in extreme circumstances that could cause problems for the booster's battery being overloaded and outcomes are "unpredictable" and potentially dangerous
  • if you're not comfortable using a booster don't use one.
• I for one have no issues using the booster and only leave it connected long enough to wake up the vehicle - I've no no issues to date.

this is little new information in this thread - other than proof the Taycan's software systems are not yet perfect at managing 12V power drain - this is unsurprising…and never a reasonable expectation for it to be otherwise. I do believe at this time Taycan is no worse (and actually better) with regards to 12V dead-battery scenarios than any ICE vehicle I've ever owned. And given the actual frequency of 12V problems it's not an issue in terms of overall quality.

nothing by the way can be done for an actual "bad" 12V battery - and they do go bad and need replacing - again this is no different that any ICE vehicle's 12V battery - they are not lifetime items, they are subject to wear/tear/age and will eventually fail and need to be replaced.

a 12V trickle charger for nearly any EV is an excellent elephant defence mechanism - i.e. the system you deploy in your home to protect you from elephant attack - I have one of these and my home as never been attacked by elephant…so it must be working. But then again no elephants have ever tried to attack my home - so we really don't know now do we? Same thing with the Taycan - the 12V battery drain is software fault that drains the 12V in a matter of hours (sometimes less than an hour) - once the Taycan's software systems are in this state _NO_ 12V trickle charger can keep up with the power demands and the 12V battery will be drained and trip offline…at which point you require a 12V booster (or actual 12V battery) to power the vehicle's systems to wake it back up…at which point the car will reset itself and Taycan will use the big battery to charge the little battery.

keep in mind the Taycan has a 94 kwh big battery that can step in and charge the 12V battery when it is low - the Taycan has full authority to use the "big battery" to charge the 12V battery when necessary - when the software is working correctly NO external power supply is required - because there is ample power in the "big battery" to top off the 12V battery for years…maybe decades…

the 12V battery has been allowed to die - then that by defination is one of two things:

• bad 12V battery that needs replacing - can happen to any vehicle
• software bug that prevented the Taycan from using the big battery to maintain the small battery…

the 1st problem won't be avoided by a trickle charger - bad battery is a bad battery nothing you can do.
the 2nd problem - why is the Taycan NOT saving itself by using the "big battery"?? This is a software bug folks and is not supposed to happen. so two bugs are happening

1. Taycan is running amok keeping something alive that is causing 12V battery usage
2. Taycan is in a state where it's not engaging the big battery to keep the 12V battery topped off (which it's supposed to do) - this is another software bug…

Again once you are in this state your 12V is probably going to trip offline - and the external 12V tickles chargers won't keep up with the demand - I'll further argue you're in a state where the Taycan's computer needs to be rebooted to get out of this state and the only way that happens is to let the 12V drop offline…it's a software bug and the computer needs to be rebooted…just like you occassionally have to just restart your phone/tablet/laptop/desktop computer and suddenly everything works better…

same things folks - software bugs sometimes requires a full reboot - the 12V battery dropping offline is a full reboot, and the problem probably won't occur again.

 

[satchurator]

this problem was more common prior to the latest updates (circa 2021) - I never expect Porsche to eliminate these problems that's impossible - just make them less frequent. My personal experience post update is that the 12V problems are far fewer and far between but still possible (as this post indicates). The recovery procedures are the same regardless of why your 12V battery is "offline", you simply need to provide power to the vehicle via the 12V jumping post in the frunk and the vehicle will cover itself…

the reason as to why the 12V drains itself are elusive and most likely software related to systems being allowed to run that should be "asleep" - this will get better over time as Porsche fixes more software bugs but the core problem can never be 100% fixed, there will always be corner cases where the software system can mistakenly keep the vehicle's systems "awake" and therefore place demands on the 12V system - causing a drain to low voltage which when reached will cut-off the 12V battery…

I am highly dubious of any 12V trickle charger mattering here for the following reasons:

• if there are no Taycan software faults the 12V tickle charger is un-necessary
• if there is a software fault keeping Taycan systems awake and draining power the power drain of Taycan systems will greatly exceed the 12V trickle charger's abilities and therefore still drain the 12V battery until it trips "offline"
  • once the 12V battery has dropped "offline" the trickle charger can not bypass the relay that has tripped and the 12V battery is effectively disconnected - therefore no power will ever reach the 12V once it's in this condition.
    • you must provide sufficient 12V power to the jumper posts to wake up/power the main computer in the Taycan for it to be alive and and reset the 12V relay
  • the fact that a 12V trickle charger is insufficient is trivally demonstarted by the fact that once the Taycan is in this state a 12V trickle charger like the CTEK doesn't provide enough power to "wake up" the Taycan's main computer
  • 12V trickle charger is nearly pointless for EV given my reasons above
• any 12V "booster" is sufficent to wake up the Taycan - and the only method other than an actual 12V battery for recovering the vehicle
  • there is _NO_ issue with lead-acid vs. liOn booster and what not - 12V power is 12V power is 12V power - and properly used the booster is only involved for 90 seconds or less…once the main computer has woken up the Taycan will recover itself - and you disconnect the 12V booster as once the vehicle is "alive" it is no longer necessary.
• The issue as to 12V boosters and the risk of using them is _NOT_ to the Taycan's systems, it is to the booster - as when the Taycan wakes and begins charging the vehicle's 12V battery that power will also flow "into" the 12V booster - potentially overwhelming the booster - in extreme circumstances that could cause problems for the booster's battery being overloaded and outcomes are "unpredictable" and potentially dangerous
  • if you're not comfortable using a booster don't use one.
• I for one have no issues using the booster and only leave it connected long enough to wake up the vehicle - I've no no issues to date.

this is little new information in this thread - other than proof the Taycan's software systems are not yet perfect at managing 12V power drain - this is unsurprising…and never a reasonable expectation for it to be otherwise. I do believe at this time Taycan is no worse (and actually better) with regards to 12V dead-battery scenarios than any ICE vehicle I've ever owned. And given the actual frequency of 12V problems it's not an issue in terms of overall quality.

nothing by the way can be done for an actual "bad" 12V battery - and they do go bad and need replacing - again this is no different that any ICE vehicle's 12V battery - they are not lifetime items, they are subject to wear/tear/age and will eventually fail and need to be replaced.

a 12V trickle charger for nearly any EV is an excellent elephant defence mechanism - i.e. the system you deploy in your home to protect you from elephant attack - I have one of these and my home as never been attacked by elephant…so it must be working. But then again no elephants have ever tried to attack my home - so we really don't know now do we? Same thing with the Taycan - the 12V battery drain is software fault that drains the 12V in a matter of hours (sometimes less than an hour) - once the Taycan's software systems are in this state _NO_ 12V trickle charger can keep up with the power demands and the 12V battery will be drained and trip offline…at which point you require a 12V booster (or actual 12V battery) to power the vehicle's systems to wake it back up…at which point the car will reset itself and Taycan will use the big battery to charge the little battery.

@daveo4EV Always appreciate your detailed and wisdom-laden advice on all things charging. Something I would really like to understand is: why the manual / GTN details both boost and trickle charge scenarios for the 12V battery. I would like to think that a Porsche-recommended battery tender like the CTEK li-ion products would be adequate in deterring both elephants and legitimate 12V drainings below a shutdown threshold.

Of course, they could be plain wrong, or just reconstituting ICE advice that is essentially placebo for EVs, but if that advice sustains through 3 Taycan model years, perhaps trickle charging the 12V battery is viable, with the right equipment?

 

[rb33gl]

while I agree with you in theory - this is the documented factory Porsche recovery process for a dead 12V/drained 12V battery on all of their vehicles - and 12V DC power is 12V DC power - there is no magic here.

once the car's 12V power system is offline (dead or tripped relay) the _ONLY_ mechanism to recover the vehicle is to provide a 12V external power source - end of story. And in the case of the Taycan lacking a manual fruck release - the ONLY way to access the approved power-supply access posts is to apply 12V power to a particular jumper-point in the fuse panel of the driver's foot well

THIS IS PORSCHE'S DOCUMENTED PROCESS TO RECOVERY THE VEHICLE - I see no alternatives.

so what are you suggesting is a better method?

1. dead 12V system - vehicle un responsive
2. manually open the vehicle's driver's door using the physical key
3. find the correct "fuse" connection in the driver's footwell for "power"
4. provide 12V power to this fuse connection point
5. use the vehicle FOB to open the frunk
6. dis-connect the 12V power source from driver's foot well
7. find the 12V "jumping" posts in the frunk
8. provide sufficient 12V power to these posts to "power" the vehicle systems
9. Taycan will "wakeup" and then recovery itself
10. disconnect external 12V power source.

the steps outlined above _ARE_ porsche's procedures
there is no alternative
it is highly unlikely your 12V power source can cause any problems if used correctly and briefly
this isn't rocket science
any latent problems after this procedure would be impossible to prove/deny/claim were caused by following porsche's proceedures or someone used an "incorrect" external 12V DC power source, for what ever that could mean…

it's really quite simple folks -you'd lap top's battery has died, you need to plug it into a power supply to wake it up…

in this Case the Taycan is a glorified lap top with a dead battery - plug it into the wall and it will wake up.

Now I’ve been through this experience you are correct in describing this as the procedure. The problem I had was the procedure (including using the emergency key) was not readily available. It is not described in the Good to know App - all it says is “Insert the emergency key into the driver's key until latched”. It’s a lot more involved than that!

 

[daveo4EV]

@daveo4EV Always appreciate your detailed and wisdom-laden advice on all things charging. Something I would really like to understand is: why the manual / GTN details both boost and trickle charge scenarios for the 12V battery. I would like to think that a Porsche-recommended battery tender like the CTEK li-ion products would be adequate in deterring both elephants and legitimate 12V drainings below a shutdown threshold.

Of course, they could be plain wrong, or just reconstituting ICE advice that is essentially placebo for EVs, but if that advice sustains through 3 Taycan model years, perhaps trickle charging the 12V battery is viable, with the right equipment?

my guess is recycled ICE advice combined with it won’t make things worse means you leave it in the manual

the real question is can it and does it actually prevent anything ? the answer is unknowable with out daily reviews of vehicle logs that we don’t have access to nor does porsche probably enable in production customer vehicles

a 12v trickle charger won’t make things worse - i’ll leave it at that

 

[Tooney]

Roadside assistance contractor Agero has Taycan-related recovery tip sheets and videos at this link: https://info.agero.com/blueprint/porsche

 

[rb33gl]

Roadside assistance contractor Agero has Taycan-related recovery tip sheets and videos at this link: https://info.agero.com/blueprint#porsche-tip-sheets

Great find, thanks
I think my Porsche Assist guy had something similar on his iPad

 

[Vercingetorix]

Once again, you're not jump starting the EV. Unlike an ICE car, there is no starter motor or alternator which you need to power. Instead with an EV. you're providing 12v power to the electronics so that the car will wake up. Once the car is back up, the car will take care of properly charging the 12v Li battery.

If the use of this device makes you uncomfortable, don't use it. Instead get a 12v lead acid battery to kick start your EV in the case of a problem. That's what the AAA trucks use.

https://www.amazon.com/Tecmate-Opti...cphy=1024543&hvtargid=pla-1090238818523&psc=1

I use one of these. 6ah Milwaukee battery to open the front trunk, and switch to this for potential dead battery. Also have an m12 compressor for flats.

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