Don Breaks His Taycan - The Saga of the 12v Battery

[wmras]

I suspect that the voltage you were seeing was actually the “charging” voltage coming from the DC-DC Converter. If I recall my EE classes correctly, you can’t actually measure the battery’s voltage while it is being charged; what you actually get is the charging voltage. You have to stop charging to get the battery’s true voltage.

If you use a current-limited source (e.g. a charger), the battery voltage is the charge-state voltage (plus a small float voltage). If you charge from an "unlimited" current source (e.g. a much larger battery) the voltage will try to be the charge state but a massive current flow will create a lot of heat and a voltage drop. Most likely, the large current flow and heat is the reason Porsche limits a jump battery connection to five minutes.

Sponsored

 

[Singularity]

Yesterday I experienced the same issue that evanevery mentioned in this thread, that is the car just starting radio playback by itself and the screen shows a loading icon (indefinitely). Car itself was not on otherwise.

I have to put a disclaimer here that this could have been my dogs fault. My dog was in the front passenger seat when this happened, so if this can be triggered by pushing something, it could have been theoretically triggered by my dog.

But what I do know is that I was not in the car when this happened, nor was the key in the car. I had simply unlocked the car and was loading stuff in there, including the dog, which went in first.

This may not be a very useful report (yet) but it is the first time anything like this has happened. Will keep monitoring for any such events in the future.

 

[louv]

I once had my cat turn on my hazard lights while I was driving. (E39 M5)

 

[louv]

Yesterday I experienced the same issue that evanevery mentioned in this thread, that is the car just starting radio playback by itself and the screen shows a loading icon (indefinitely). Car itself was not on otherwise.

I have to put a disclaimer here that this could have been my dogs fault. My dog was in the front passenger seat when this happened, so if this can be triggered by pushing something, it could have been theoretically triggered by my dog.

But what I do know is that I was not in the car when this happened, nor was the key in the car. I had simply unlocked the car and was loading stuff in there, including the dog, which went in first.

This may not be a very useful report (yet) but it is the first time anything like this has happened. Will keep monitoring for any such events in the future.

I tried it today. Car on. Music playing (Barry White, if you care). Turn car off (with power button). Music keeps playing. Open driver’s side door. Music stops. Touch upper central display. Music comes back on (lower center display comes on. Dashboard display stays off). Woof. I’m a dog!

 

[louv]

My car now has ALL THE CAMPAIGNS!!!

WLE3 - 12v vehicle battery with updated firmware.
WLD0 - Replace hi-voltage line from HV distributor to E-box.
WLF2 - Check & Replace seat belt latches.
WLH5 - Drain plug adjustment (AC condensate drain).

Now I can re-test and see if I can cause the car to drain the 12v battery. Cross your fingers and wish me luck!

 

[LonePalmBJ]

My car now has ALL THE CAMPAIGNS!!!

WLE3 - 12v vehicle battery with updated firmware.
WLD0 - Replace hi-voltage line from HV distributor to E-box.
WLF2 - Check & Replace seat belt latches.
WLH5 - Drain plug adjustment (AC condensate drain).

Now I can re-test and see if I can cause the car to drain the 12v battery. Cross your fingers and wish me luck!

I can't wait to hear what you break next!


Jokes aside, thanks for being the vanguard that smooths the way for the rest of us

 

[jetbox]

How can you tell which campaigns are done and which are not? I never get any paperwork when my car has been in for software updates so no clue what has and has not been done?

its all working fine though, which is goooood

 

[evanevery]

I don’t know. My car was delivered June 24. But it is normal that the 12V battery is fully loaded instantaneously?

The battery doesn't have to be fully loaded instantaneously, all it has to have is the high-voltage charging circuit supplementing it so the car THINKS it has a full 12V. Its the charging circuit that's likely providing the "visible" 12V - not the battery.

 

[louv]

How can you tell which campaigns are done and which are not? I never get any paperwork when my car has been in for software updates so no clue what has and has not been done?

its all working fine though, which is goooood

I get paperwork when I leave. As should you. Or an email. Something telling you what was done. Or your Service Advisor is dropping the ball.

That said, my car was very early production, so nearly all of the fixes that have been issued need to be applied to my car. If you just received your car, maybe none of these apply to your car.

Your service advisor can enter your VIN into their system and instantly know what has or hasn’t been done.

 

[Genau]

I once had my cat turn on my hazard lights while I was driving. (E39 M5)

By any chance was your cat named Toonces?

 

[lasik]

You know your Taycan has a 12v battery, right? Do you know where it is? Do you what to do if it goes completely dead?

UPDATE July 30, 2020: tl;dr? Jump to Reply #297 for the Fixes to this problem.



I do. Now. I didn’t pay much attention to it until yesterday morning. I mean, I knew it was there... somewhere. Probably.

Go grab a cup of coffee... aw, hell, you are probably stuck at home, Sheltered in Place, so go grab a beer... and come along for a new (but hopefully NOT epic) adventure.

Two days ago I finally had a crew out to the house to install a new Charging Station in my driveway. I started that process last November, but by the time the electricians could schedule it, the ground had frozen (remember: Maine) and the couldn't trench my driveway. "We'll come do it after the spring thaw." Well, now I have a ChargePoint Flex, capable of charging at 50A (the Taycan can only handle 40A, or 9.6kW), I fired it up, connected it to my WiFi, name it, set it to know that it was connected to a 50A breaker, and therefore limit itself to 40A.

I connected up to the car, and set up my Profiles and Timers. My location-aware Profile creatively named "Home" was set to have a minimum charge of 50%, and preferred charging times of 10PM to 5AM. I set up a Timer, Target charge of 90%, 7 days a week, departure time of 3AM, no climate control. All went as expected. The car was at 40% when first plugged in at 4PM. It immediately charged it self to 50%, then stopped charging, as expected. Then at 10PM it started charging... slowed down a couple hours later, and then picked up again and finished charging at 3AM at the requested 90%. Odd that it charged and stopped and charged again... but whatever, the end result was As Requested.

That's the setup. Most of that is PROBABLY all coincidental to what comes next. I am not implying any connection, just setting the stage.

The next morning, yesterday, I wake up and check the iPhone app at about 7:30am: the car is nicely charged as requested.

At 9:51am, my phone rings from an unknown number. I answer, and it's the Porsche Connect Security Team. "There's a problem with your car." "What's the problem?" "First you need to answer your two security questions..." <redacted> "<laughter> Yup, that's right. OK, either your car was broken into or there a problem with the battery." "Uh... those are really different things. OK, I'm out at the car now. No problems. No windows broken, no damage." "OK, well, have a good day, Call us back if you have any questions."

At this point I notice the car hasn't automatically unlocked. Odd. I grab the remote from my pocket and press the unlock button. No joy. I think maybe it's the remote. I read in the "Good To Know" Manual, to place the key near the upper right corner of the rear window and press unlock. Nope. Nothing.

I look at the Porsche Connect App now... It looks like this:

OK, let's try the Emergency key.
1) Pull it out of the remote.
2) Lift the driver's door handle, look underneath
3) Insert key, and turn.
Door unlocks and opens.

Car is still dead. No dash lights. Nothing. Press Start button. Nothing.

OK. This is all I know how to do. Time to call Roadside Assistance. And get my car towed.

Before the car can be towed, I have to unplug from my Charging Station. Hmmm. The car is locked. The car won't let go of the charger plug. There *must* be an emergency release somewhere. Back to the "Good To Know" app, to read the manual.

To Remove the Charging Stations' plug from the car:
1) Open the front door, on the side where you are plugged in.
2) Look for a round button at the top of the front body panel.
3) Pull on that knob, which is connected to a cord, which will release the lock on the charging station plug.

Tow truck arrives 20 minutes later. But, since the car is completely powerless, it can't be put into neutral. And he says, "I don't have dollies in this truck, and there's no way I'm going to drag that beautiful car up onto the truck." So, he goes away.

I call my local dealership's service department. They send out their head technician to my house.

Since the Tech is coming from his house, where he'd been sheltering in place, he had to go to the shop, get some tools, and then drive to my house, I know I have some time. So I read further into "Good To Know".

I discover instructions for applying power to the 12v system, so that the Frunk can be opened (and then the 12v Battery can be accessed directly). I go in the house, grab a spare 12v battery, and some charger clips and go back outside.

To Apply 12v Power to the car, when the car's 12v Battery is dead:
1) Open the fuse panel (to the left of the driver's side footwell)
2) Find the Red 12v Positive Terminal, and pull it out about 1/2 inch.
3) From your spare 12v Battery, Attach 12v Positive to that terminal.
4) From your spare 12v battery, attach negative to the hinge of the car. (bare metal)

At this point, I hear relays switching on and off... kinda like it was trying to connect, something was failing, and then it would try again. After 10 seconds of that, I disconnected. Never mind. I don't know what's really wrong, so I'm just going to stop.

Soon after, the technician arrives.

He connects a bigger batter to the same places. And tries to turn on the car. No joy. We wait a few minutes. Still nothing.

Then he says he needs their Lithium Ion Battery Charger. So a quick, 10 minute run back to the shop, he grabs the big charger. Meanwhile, I run a 100 foot extension cord so he can plug in the charger.

When he returns, and attaches the big charger, the car wakes up enough that we can pop the hood. Now we have access to the actual 12v Lithium battery, so the charger can do a better (read: faster) jobber-charging the 12v Battery.

After charging for about 5 minutes, the valiant Technician attached their diagnostic computer to the ODB-II connector, and collects some diagnostic data from the car.

We let it charge, and download data for another 10 minutes or so, and now everything seems fine.

We remove the brick from under the front wheel. (in case we needed to put it in neutral... I didn't want the car rolling downhill into the street). And he drives the car back to the Dealership, leaving me with a nice silver Cayenne loaner.

Later that day they asked for more details on the charging sessions, to try and analyze what happened when. I was able to send charge session logs from ChargePoint, and via security camera footage, identify exactly when the battery went dead. (the charge port blinking light turned red, and the went out)

That's where this chapter ends.
Stay tuned for more adventures in "Don Breaks His Taycan" (again).

Second time for dead 12 V on my Turbo S for me. The dealer took it for 2 days the first time and "fixed" it with software update (my wife's Tesla updates software automatically in the comfort of our own garage). In the process they broke the charging cable release... Holiday weekend this time. Informed roadside assistance will not jump this car, only option is towing. So much for roadside assistance. Texted my salesperson, naturally no response. Not interested in having the car dragged from my garage to just sit at the dealer or tow lot for days so I am familiar with the frunk procedure from my 911 so will try this with your detailed instructions.... Thanks. Also, read that once restarted, battery should be OK? Have also read that there are electrical error messages and battery may need to be replaced altogether. Cannot imagine that dead battery 2X can help the longevity of this battery.

 

[louv]

Second time for dead 12 V on my Turbo S for me. The dealer took it for 2 days the first time and "fixed" it with software update (my wife's Tesla updates software automatically in the comfort of our own garage). In the process they broke the charging cable release... Holiday weekend this time. Informed roadside assistance will not jump this car, only option is towing. So much for roadside assistance. Texted my salesperson, naturally no response. Not interested in having the car dragged from my garage to just sit at the dealer or tow lot for days so I am familiar with the frunk procedure from my 911 so will try this with your detailed instructions.... Thanks. Also, read that once restarted, battery should be OK? Have also read that there are electrical error messages and battery may need to be replaced altogether. Cannot imagine that dead battery 2X can help the longevity of this battery.

Sorry to hear that.

Yes, once restarted, it should be ok. But take it out for a 15 minute drive to give the big battery a chance to recharge the 12v battery. (It will probably recharge the 12v battery just by being On and parked, but I never got clarification on the details when 12v charging starts & ends)

Do you know if your car has the “new” 12v battery?

What was your delivery date?

Ask your service advisor if your VIN requires the WLE3 Campaign (12v battery).

If your car puts up error messages about the 12v battery every time you turn the car on, then it has damaged the battery by drawing it down too far. If you only get one of those messages, and it doesn’t reoccur, then it should be fine.

 

[lasik]

Sorry to hear that.

Yes, once restarted, it should be ok. But take it out for a 15 minute drive to give the big battery a chance to recharge the 12v battery. (It will probably recharge the 12v battery just by being On and parked, but I never got clarification on the details when 12v charging starts & ends)

Do you know if your car has the “new” 12v battery?

What was your delivery date?

Ask your service advisor if your VIN requires the WLE3 Campaign (12v battery).

If your car puts up error messages about the 12v battery every time you turn the car on, then it has damaged the battery by drawing it down too far. If you only get one of those messages, and it doesn’t reoccur, then it should be fine.

Thanks! I was supposed to be the first for delivery since I had a deposit on the car for 2 1/2 years! Ended up being the last, just got about a month ago (and the 2021 are out soon?). I hope it has the "new" battery. Will check with dealer... Thanks

 

[Reg]

(my wife's Tesla updates software automatically in the comfort of our own garage).

Yes, we get it, Tesla can update from the comfort of your own garage - including updates that nerf the range of the S and updates that cause cars to have more frequent phantom braking.

 

[B777]

It’s odd that the 12volt battery doesn’t have cutoff at min cell voltage
To keep from killing the battery by going completely depleted ??
oops not sure you can do that with a LiFe

Sponsored