Pt.2: Taycan lets you drive with shorted out battery modules [VIDEO]

[ct14garage]

This is a continuation of this thread:
"Taycan lets you drive with shorted out battery modules"


Many people were skeptical of the contents of that post. So today I was so impressed by the condition of the battery of a car which arrived driving to our shop that I decided to make a video about it!!
https://youtu.be/aJyrjH5otbQ



In the video we also showcase the power of tCAN-Pro a software tool developed in house by CT14 GARAGE which provides AI powered Taycan battery diagnosis. Free for everyone to use here!


[FREE] tCAN-Pro - TAYCAN BATTERY DIAGNOSIS FOR THE COMMUNITY

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[Tooney]

Thank you for the video.
1. Does 'short' mean the module is energizing the vehicle chassis or just the HV battery or module container?
2. What are the most likely cause(s) for a module shorting? What is actually going on to make the short?
3. In what ways can a "shorted" module cause harm to the car or people?

 

[Sly_North]

Hi, thanks for the video. 2 very minor improvements for your next video:

• "Download the battery" - I'd rather say "dismount the battery from the car", download is for internet software for me.
• And at the end when checking the battery resistance: start with a good module to show how a huge difference there is (though you did mention it; but a visual is always much stronger than a few words that one might miss).

 

[ct14garage]

Hi, thanks for the video. 2 very minor improvements for your next video:

• "Download the battery" - I'd rather say "dismount the battery from the car", download is for internet software for me.
• And at the end when checking the battery resistance: start with a good module to show how a huge difference there is (though you did mention it; but a visual is always much stronger than a few words that one might miss).

Yes the reason is that in Porsche’s workshop repair manual the chapter related to dropping the battery is literally called “Downloading of HV battery”. So I used Porsche’s term for it…

Regarding the good modules there’s not many good modules on that battery at all ???

 

[ct14garage]

Thank you for the video.
1. Does 'short' mean the module is energizing the vehicle chassis or just the HV battery or module container?
2. What are the most likely cause(s) for a module shorting? What is actually going on to make the short?
3. In what ways can a "shorted" module cause harm to the car or people?

1. A shorted module means it’s leaking current to ground. Something that should never happen under normal conditions.

2. Swollen pouch cells are a key cause of shorts. As the cells expand inside the rigid metal module housing, they eventually press against the casing. In severe cases, the swelling causes the cells to rupture internally, massively increasing current leakage.

3. A shorted module is a serious fire risk. It can easily trigger a thermal runaway event, especially during DC charging. Once this starts, the fire spreads rapidly within the battery pack and can engulf the entire car.

What’s worse, in this case, the battery frame itself becomes electrically live, carrying current due to the internal leakage. Since the frame is bolted directly to the car’s chassis, this creates a real risk of electric shock, particularly when entering or exiting the vehicle. This is exactly what our customer experienced.


That said, even in this degraded condition, a thermal event might not happen right away. The car may still accept quite a few DC charges before anything goes wrong… but you’re playing with fire, literally. The battery’s built-in safety system, the BMS, is supposed to detect isolation faults and shut the pack down. In this case, it clearly failed. So there are no protections in place anymore. Just pure luck and the fact that battery fires are extremely rare but not impossible!


I have no doubt Porsche is aware of this issue. I’d go as far as saying that every single Taycan that caught fire without an impact likely did so due to this failure mode, which Porsche has internally referred to as ARB6.

Let’s hope the latest software update improves the BMS and enforces a much earlier shutdown when isolation loss is detected

 

[Uknown]

Thanks for sharing

 

[tonycolin]

thanks for exposing this, hopefully this pushes porsche to do something sooner rather than later

 

[Dee]

thanks for exposing this, hopefully this pushes porsche to do something sooner rather than later

I do hope so but I think LG is at fault here.
Porsche should demand new, safer cells and a proper BMS for their customers cuz this is going wrong sooner or later.
I think Porsche's good name is at stake here although LG should get the blame.

 

[Rik_CT4s]

This is a continuation of this thread:
"Taycan lets you drive with shorted out battery modules"


Many people were skeptical of the contents of that post. So today I was so impressed by the condition of the battery of a car which arrived driving to our shop that I decided to make a video about it!!




In the video we also showcase the power of tCAN-Pro a software tool developed in house by CT14 GARAGE which provides AI powered Taycan battery diagnosis. Free for everyone to use here!


[FREE] tCAN-Pro - TAYCAN BATTERY DIAGNOSIS FOR THE COMMUNITY

Many thanks Christian. Great job you are doing!

What I find hard to understand, except for the financial impact for Porsche / LG, is that supposedly as stated by Porsche only a limited number of batteries have these kinds of serious errors.

This while the batteries are assembled in the same way and delivered by the same suppliers in the same composition to my knowledge.

The software that will come from Porsche may detect some deviations, but the basic problem is still just a faulty battery, regardless of whether the software indicates something or not.

My point is: sooner or later every Taycan will have problems with that battery, to a greater or lesser extent. The problems that I see in this video are very serious.

Wondering how you view this especially in light of the high number of faulty Taycans that are being repaired in your garage.

 

[Murph7355]

Really interesting video - thank you for posting.

Have ordered an ENET cable and will see what my car reads.

As Rik notes, the new BMS software, should it ever arrive, will be useful, but it isn't fixing the underlying problem/risk.

It also makes you wonder why Porsche cannot get the BMS software out. An independent garage can create a great app like this... But Porsche can't in the 9mths (?) or so that they've known about this problem. It's a joke.

They should get on the phone to you and pay you for the source code. As soon as a module shows red, shut the pack down.

The cynic in me suspects that as soon as they do this, they know they need a fix for the underlying issue. And the bean counters don't want to be on the hook for replacing battery packs en masse.

They are going to be in deep shit if this issue causes much bigger losses than just a car going up in flames.

(What did your customer experience in terms of electric shock? I'd ha e expected the battery pack to be fully isolated from passengers).

 

[Murph7355]

I do hope so but I think LG is at fault here.
Porsche should demand new, safer cells and a proper BMS for their customers cuz this is going wrong sooner or later.
I think Porsche's good name is at stake here although LG should get the blame.

Porsche's name is already sullied by this.

They should be doing the right thing by their customers first, and worry about their come back on LG second. Our "contracts" are not with LG.

The Taycan's an amazing car. But it's clear that the engineering is lacking in some key areas. That's what Porsche's reputation is built on. If they lose that, they have nothing.

 

[ct14garage]

My point is: sooner or later every Taycan will have problems with that battery, to a greater or lesser extent. The problems that I see in this video are very serious.

In my experience with around 300 Taycans repaired at my garage and around 500 Taycan VINs that I’ve printed PCSS reports for forum members… Out of every 10 VINs 8 are flagged for ARB6.

So yes all those cars flagged by ARB6 sooner or later will end up like this. Matter of time only. Not short term of course but we’re talking years!

 

[ct14garage]

What did your customer experience in terms of electric shock? I'd ha e expected the battery pack to be fully isolated from passengers).

Well customer reported that every time he got into the car or out of it he would get electric shock in the lower legs from the door sill area.

I could never reproduce this and myself didnt experience the shock.

BUT, given that the battery frame was LIVE at over 700 Volts I have no reason to doubt him.


Also it’s not the first customer who comes to us with such a big problem and reports the same shocking in the lower legs when entering the car or exiting.

 

[ct14garage]

Also to add, Porsche’s software update to the BMS while it obviously wont fix the underlying issue.

It will prevent a disgrace as long as it shuts down the battery pack as soon as it detects a fully shorted module or right before.

There can’t be no short circuit and thus no possible thermal event as long as the contactor is open (battery shut down). It also can’t shock anyone as long as the contactor is open, that’s for sure. So safety first ??‍

 

[chun]

So yes all those cars flagged by ARB6 sooner or later will end up like this. Matter of time only. Not short term of course but we’re talking years!

In my opinion, Porsche is planning to close the recalls with the solution: "we released a new BMS software that will address all problems", and then within the 8 years of warranty replace modules when indicated by the new BMS software, and after the 8 years warranty put owners on the hook for the expenses of repairing the battery - even though the battery has hardware issues since day 1.

I guess we will find out soon, if they close the recall with the release of the software or not.

I am almost sure that Porsche is not planning to offer any battery repairs beyond those 8 years of warranty on their dime, even though the battery has been faulty hardware wise since day 1. A software solution should not be accepted to a hardware problem

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