12v battery dead....again ('23 CT)

[Jagu]

Link:
https://www.amazon.com/CTEK-56-926-LITHIUM-Automatic-Phosphate/dp/B00EUF6UM8/?th=1

Thanks very much.

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[ThaJamez]

I assume every Ctek supporting Lithium batteries can be used?

 

[ItsNot AboutTheMoney]

Similar 12V issues have been reported, this posting might be useful:

https://www.taycanforum.com/forum/t...charger-or-charging-station.23806/post-365733

 

[M3Taycan]

Spoke to the guy at the dealership earlier. He seems to think it's something to do with a software update which landed in December - apparently it kept 'waking the car up', which causes the 12v to drain. I dont know why they didn't update the s/w when my car was with them over Xmas. What I dont understand, however, is why the battery wouldn't charge when plugged in or when the car was being driven. The HV battery on my car has consistently been above 70%.

I'll keep this thread updated with what Porsche find, but similar to others, I feel like I have a CTEK in my future.

Your key fob will communicate with the Taycan periodically (0 to ~75 ft line of sight - no obstacles). I suggest storing your keyfob in a Faraday bag. A Faraday bag can be purchased on Amazon. The cheapest alternative is to completely cover your keyfob in aluminum foil (when not in use) since it will block the wireless communication signals between the keyfob and Taycan.

 

[anonymouse]

completely cover your keyfob in aluminum foil (when not in use) .

no need for a tinhat, nor a faraday cage. If you have to store your key within range of the car then hold down the top two buttons for a moment until the lights flash; the key is then disabled until you press a button.

But in any case I thought modern keys go to sleep if not moved for a while, to stop relay attacks?

 

[Dee]

You can check your battery health and DC/DC charger in the car.
Select the 12V battery in the right tube of your dash.
<13,5V your battery is dying, it doesn't charge.
13,6V your battery is charged.
>13,7V your battery is charging (@~14V)

 

[anonymouse]

I am pressing my OPC for some information from Porsche on these battery failures.


Nothing so far other than
- if the battery has been jump started then "there should be no further issues" (disproven by some on here)
- "due to a period of not driving for a long period" - again this is not correct because we are seeing failures after just 9 days.


Have encouraged them to keep pushing Porsche on this. Hope others are doing the same -do come back and tell us if you get anything concrete.

 

[f1eng]

I assume every Ctek supporting Lithium batteries can be used?

When I looked there was only one CTEK supporting Li batteries.
I seem to remember there was a Porsche branded charger suitable for both offered at one time but I couldn't find it listed any more when I looked earlier this week so I bought the CTEK which arrived today and works fine - including a way to reset a battery in protection mode.

 

[kurand]

Just got my Tacan back from PRG Reading where it has been recovered via Porsche Assistance on Moday because of a repeatedly empty 12V battery. Alongside testing the 12V battery and car idle current drain (78mA) for several days, they also applied workshop campaign WRW1 supposedly designed to sort out the this kind of problem. My service assistant mentioned that they have had a lot of 12V battery problems over the last 6 weeks or so. He said that it is due to a failed OTA update that causes repeated attempts to do the update that flattens the battery. WRW1 supposedly reprograms the external communication control unit (OTA-FC) which mitigates the problem. Not sure exactly how. Perhaps it limits attempts?

I'm somewhat sceptical that this will address the problem, but I'll wait for it to fail one more time before splashing out on a lithium battery maintainer.

 

[anonymouse]

workshop campaign WRW1 supposedly designed to sort out the this kind of problem.

Thank you for this intel - at last we might be getting somewhere. Let's see how your experiment goes now. My OPC is going to follow up with their Porsche rep on Monday and see if they confirm anything.

 

[anonymouse]

In another forum an owner reports being pushed an OTA update “external communication CU (WRW1)”. So maybe some cars could be getting a fix? (might only be new model.)

 

[rhizome]

Is there any way to disable OTA updates.? This is extremely frustrating. Took a 90 minute drive 2 days ago, plugged in and charged up to 85%. Today it took me a few attempts to get into the car and get it turned on. due to low 12V.

 

[eddieterry]

Just got my Tacan back from PRG Reading where it has been recovered via Porsche Assistance on Moday because of a repeatedly empty 12V battery. Alongside testing the 12V battery and car idle current drain (78mA) for several days, they also applied workshop campaign WRW1 supposedly designed to sort out the this kind of problem. My service assistant mentioned that they have had a lot of 12V battery problems over the last 6 weeks or so. He said that it is due to a failed OTA update that causes repeated attempts to do the update that flattens the battery. WRW1 supposedly reprograms the external communication control unit (OTA-FC) which mitigates the problem. Not sure exactly how. Perhaps it limits attempts?

I'm somewhat sceptical that this will address the problem, but I'll wait for it to fail one more time before splashing out on a lithium battery maintainer.

Thanks for updating us - lets hope this is the cure for the 12 Volt recent problems as although using a CTEC maintainer is no big deal it should not be necessar..

 

[M3Taycan]

no need for a tinhat, nor a faraday cage. If you have to store your key within range of the car then hold down the top two buttons for a moment until the lights flash; the key is then disabled until you press a button.

But in any case I thought modern keys go to sleep if not moved for a while, to stop relay attacks?

Delayed sleep features on key fobs don’t provide uniform protection, as manufacturers set different sleep times. Forgetting to activate manual fob sleep can leave you vulnerable to relay attacks. To safeguard my car, I store my key fob in a Faraday bag after locking the doors. Before getting in, I take the key fob out of the bag. Be aware that an experienced thief can relay the signal from your key fob with just one transmission. Currently, there’s no foolproof method to prevent relay attacks. As a precaution, consider using a physical key to lock and unlock your car, then retrieve the key from the Faraday bag when in the locked car.

Here is a link to an article on the topic: https://www.whatcar.com/news/more-car-models-get-sleeping-key-fobs-to-combat-keyless-theft/n20439

 

[f1eng]

So I took my dog out into the countryside for a walk.

10 miles there and back and when I got back and switched off I got a warning box saying PCM can't be used because battery is low.

I got out my new CTEK charger which showed the battery was >95% yesterday and it started charging and took around 40 minutes to get back to where it was yesterday, so on such a short journey it seems it is overall discharging, ie whatever the charge current from the HV battery DC-DC converter is is less than the battery is needing to supply running the car.

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