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Another 12V issue

MN_taycan

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Not to repeat others, but had a major 12V issue this morning. Taycan last driven 3 days ago. Overnight timer set for 85% max at 7am. no issues at all so far with mobile charger with 40A max. 385 total miles....should mention, very fun miles!

Go to car in morning All dark. Locked, so learned how to manually open door. Learned how to release charger connection manually on passenger side (who knew there was a string involved?). Porsche roadside contractor and I learned together how to jump the fuse panel in order to get enough juice for the frunk to open. Put the charger on the 12V terminals up front...and like magic, everything lites up inside. “Low 12V warning” on the display,, but otherwise fine.

Had them take the car to dealership to evaluate. My theory is some software sequence Is setting up an electrical drain on the 12V system. The modern day equivalent of leaving the lights on overnight in my 1972 240Z which would have the same net effect.

will post if I get any meaningful info from dealership.
 

wmras

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Not to repeat others, but had a major 12V issue this morning. Taycan last driven 3 days ago. Overnight timer set for 85% max at 7am. no issues at all so far with mobile charger with 40A max. 385 total miles....should mention, very fun miles!

Go to car in morning All dark. Locked, so learned how to manually open door. Learned how to release charger connection manually on passenger side (who knew there was a string involved?). Porsche roadside contractor and I learned together how to jump the fuse panel in order to get enough juice for the frunk to open. Put the charger on the 12V terminals up front...and like magic, everything lites up inside. “Low 12V warning” on the display,, but otherwise fine.

Had them take the car to dealership to evaluate. My theory is some software sequence Is setting up an electrical drain on the 12V system. The modern day equivalent of leaving the lights on overnight in my 1972 240Z which would have the same net effect.

will post if I get any meaningful info from dealership.
Nicely documented.
 

Tay Tay

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For you Ferrari owners this is a familiar story, which is why they're always on battery tenders (even beyond the ones that are sitting around collecting dust). I thought Porsche was better than this.

This seems like a common problem though with hybrids/EVs and I don't understand why. I assume the traction battery is able to charge the 12V so how hard can it be to keep the 12V charged while the traction battery has enough power?
 

Christian J

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For you Ferrari owners this is a familiar story, which is why they're always on battery tenders (even beyond the ones that are sitting around collecting dust). I thought Porsche was better than this.

No kidding. I have battery tenders throughout my garage but none of them will work correctly with the new 12v in the Taycan. It seems like we might want to have one handy?
 

Mouse House

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Not to repeat others, but had a major 12V issue this morning. Taycan last driven 3 days ago. Overnight timer set for 85% max at 7am. no issues at all so far with mobile charger with 40A max. 385 total miles....should mention, very fun miles!

Go to car in morning All dark. Locked, so learned how to manually open door. Learned how to release charger connection manually on passenger side (who knew there was a string involved?). Porsche roadside contractor and I learned together how to jump the fuse panel in order to get enough juice for the frunk to open. Put the charger on the 12V terminals up front...and like magic, everything lites up inside. “Low 12V warning” on the display,, but otherwise fine.

Had them take the car to dealership to evaluate. My theory is some software sequence Is setting up an electrical drain on the 12V system. The modern day equivalent of leaving the lights on overnight in my 1972 240Z which would have the same net effect.

will post if I get any meaningful info from dealership.
Thanks for a nice description. As you've said "another" 12V issue I'm guessing you're familiar with louv's thread. Do you know if your car has the software updates and new 12V battery?

I guess these are the problems with buying a completely new car design. Still a bit disappointing.
 

KensingtonPark

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This seems like a common problem though with hybrids/EVs and I don't understand why.
Every Plugin Hybrid/EV I have owned (Chevy Volt, Volvo T8, Tesla Model S) has had a dead battery like this. Eventually, some combination of software/hardware update and behavior made the problem go away. For all three cars, I started locking the car before charging, believing that locking the car when parked would prevent any weird logic in the car from believing that someone was inside. I have no idea if it really helped.

Strangely enough, it has NEVER happened to me with an ICE vehicle.
 
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MN_taycan

MN_taycan

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Thanks for the note on new 12V battery and software updates - will ask today at local dealership. Took delivery in late July from out-of-state dealer, so haven’t had any updates since. Perhaps interestingly I was scrambling around a bit when I last plugged it in - did I do something unusual sequence-wise inside or outside the car before I locked it with the fob that set it up for a 12V drain? Don’t know.

I will be buying a new robust 12V charger to keep around. When you can’t open the hood without power, you are really stuck. I wouldn’t trust jumping the fuse panel with another vehicle. Might be fine, but just seems like a bad idea.
 

Mouse House

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I will be buying a new robust 12V charger to keep around. When you can’t open the hood without power, you are really stuck. I wouldn’t trust jumping the fuse panel with another vehicle. Might be fine, but just seems like a bad idea.
Would be great if you can tell the thread when you find out if you have the updates.

Regarding the 12V charger, the battery is a lithium one so make sure the charger you get is suitable. Sorry if this is obvious!
 
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MN_taycan

MN_taycan

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No, not obvious- good note on lithium compatible chargers. Particularly the auto detect ones for linear lead-acid discharge would likely be a problem. Going to snoop around the Porsche service center to see what they use.

Looks like from other thread there is a WLE3 service bulletin for potential battery replacement. We’ll see if that’s where I end up- seems likely.
 
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MN_taycan

MN_taycan

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OK - here is the report from local dealer service. My VIN is not part of the WLE3 service notice (to replace 12V battery). 12V battery *appears* to be functioning normally. Something (TBD, by me, I suppose) caused the battery to drain - even though I would have thought by locking doors it would shut down all ancillary draws. I have an old 2004 BMW 325xiT that used to have a parasitic electrical draw - was the most annoying issue but could at least be solved easily with jumper cables and a trunk-accessible battery. BMW finally figured it out and fixed it several years later - was a radio issue (even with radio off). The challenge with the Taycan is the need for a multi-step process if the 12V system is totally dead. It's a little intimidating to be staring at the outside of this beautiful new car and think you might screw it up with occasional DIY electrical "re-boots." But I suppose I'll get used to it.

Will be buying both a beefy 12V stand-alone jump-start unit (for the potential fuse-jump/terminal jump process with a totally dead car - I need a new one anyway for all cars) and a 12V LI battery trickle unit.

Get the Taycan back this afternoon. Should be a fun, fast weekend.
 

Mouse House

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Hmm, interesting. Did the Porsche guys say whether you have had the software updates?

I will probably get a charger and a jump starter just in case, as they are not that expensive.

More research needed but these look pretty good (and crucially can be bought here in Switzerland!)
https://no.co/genius5
https://no.co/gb40
 

louv

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OK - here is the report from local dealer service. My VIN is not part of the WLE3 service notice (to replace 12V battery). 12V battery *appears* to be functioning normally. Something (TBD, by me, I suppose) caused the battery to drain - even though I would have thought by locking doors it would shut down all ancillary draws. I have an old 2004 BMW 325xiT that used to have a parasitic electrical draw - was the most annoying issue but could at least be solved easily with jumper cables and a trunk-accessible battery. BMW finally figured it out and fixed it several years later - was a radio issue (even with radio off). The challenge with the Taycan is the need for a multi-step process if the 12V system is totally dead. It's a little intimidating to be staring at the outside of this beautiful new car and think you might screw it up with occasional DIY electrical "re-boots." But I suppose I'll get used to it.

Will be buying both a beefy 12V stand-alone jump-start unit (for the potential fuse-jump/terminal jump process with a totally dead car - I need a new one anyway for all cars) and a 12V LI battery trickle unit.

Get the Taycan back this afternoon. Should be a fun, fast weekend.
Sorry to hear you are having 12v battery problems.

You don’t really need a beefy charger. (For recovery) All you need to do is get a little bit of charge back into the 12v to the point that the car wakes up. At that point the 800v battery will take over charging the 12v battery.

Not sure if you found what the Service department uses: it’s an 80A charger. Way overkill for home needs. Probably cost a pretty penny as well.

If your car had the latest software, and had the new 12v battery, then it seems like there’s still a bug hiding in there.

<grabs popcorn>
 
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MN_taycan

MN_taycan

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You don’t really need a beefy charger. (For recovery) All you need to do is get a little bit of charge back into the 12v to the point that the car wakes up. At that point the 800v battery will take over charging the 12v battery.

Not sure if you found what the Service department uses: it’s an 80A charger. Way overkill for home needs. Probably cost a pretty penny as well.
Thanks. you are right, that was my experience - it was a very short time with not much oomph to get enough juice for everything to power back on.

One important additional thing I figured out...when I was waiting for the tow truck, I thought the most important next step was ejecting the plugged in charger. So I "pulled the cord" (literally) on the inside of the passenger side door jamb and released the locked charger plug manually.

I was pretty proud of myself, until I realized that I should have just waited to power up the car and eject the plug the normal way...because that emergency cord-pull mechanism is a "use once" thing. Porsche has to order a replacement part. Not too big a deal, but I now have a cord hanging in the space along the inside of door jamb for the time being.
 
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MN_taycan

MN_taycan

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This is what I now recommend NOT doing, unless you absolutely have to - "Visit a Workshop" is apparently code for "you'll now need a new part." BTW, you need to have mouse hands to get your fingers on this pull cord anyway.
IMG_3668.jpg
 
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