Recall (9/1/23): Insufficient Sealant Causing High-Voltage Battery Leak on 2023 Taycans APB2 (4,777 Units Affected)

[rs38]

you can program some things depending on the ECU. E.g. retrofitting stuff

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[DougFrisk]

VCDS offers some:

isolation_resistance_battery_minus-Status	valid
isolation_resistance_battery_minus-insulation_resistance	2050	kOhm
isolation_resistance_battery_plus-Status	valid
isolation_resistance_battery_plus-insulation_resistance	10000	kOhm
isolation_resistance_system_minus-Status	valid
isolation_resistance_system_minus-insulation_resistance	2540	kOhm
isolation_resistance_system_plus-Status	valid
isolation_resistance_system_plus-insulation_resistance	2420	kOhm

As an occasional FRC robot inspector I can state that level of resistance between the frame and battery is within the rules and I'd pass that robot. Though given an 800 volt instead of a 12 volt system the leakage would be under .2 watts. That would take about fifty years to drain a charged PB+.

 

[neo402]

Well my VIN is in the range! Just took car a month back. I guess will wait for dealer to contact. The recall link posted does not yet say open recall for my car.

 

[Tooney]

What is insulation/isolation resistance? How does it potentially indicate a battery that allows water to leak into it?
Edit: couple of links which help:
https://www.batterydesign.net/isolation-resistance-of-a-pack/
https://static.nhtsa.gov/odi/tsbs/2013/SB-10052460-6095.pdf

 

[DougFrisk]

What is insulation/isolation resistance? How does it potentially indicate a battery that allows water to leak into it?

The entire high voltage systems should be isolated from the frame of the car. The measure of that isolation is the electrical resistance measured in Ohms between the high voltage wire and the frame of the car, or in this case likely the frame of the battery assembly. The battery assembly has a pair of high voltage wires that comes through the front of the battery and another pair that comes through the back. Those measurements would be measuring the electrical resistance from the copper wires to the frame of the battery assembly.

The lower the resistance the more power is lost leaking from the positive to negative terminals through the frame of the car. If the resistance were to get low enough that heat started to be generated problems would occur.

Water by itself is non-conductive, but if you add just a little bit of salt or other contaminants it can reduce electrical resistance significantly. Water could reduce the isolation, but no matter how the electrical isolation is compromised, if it's compromised that's a very bad thing.

WNT8 involved sending a VAL to Porsche then sending another to Porsche 50+ days later. It's quite possible they are looking for changes in the isolation resistance over time and using that as a proxy for moisture in the battery.

Somewhat off topic, but this is literally me about to measure the electrical isolation of an FRC robot last spring.

 

[Tooney]

WNT8 involved sending a VAL to Porsche then sending another to Porsche 50+ days later. It's quite possible they are looking for changes in the isolation resistance over time and using that as a proxy for moisture in the battery.

Makes a lot of sense. Thank you for the isolation/insulation resistance explanation.

 

[snstevens]

What is insulation/isolation resistance? How does it potentially indicate a battery that allows water to leak into it?
Edit: couple of links which help:
https://www.batterydesign.net/isolation-resistance-of-a-pack/
https://static.nhtsa.gov/odi/tsbs/2013/SB-10052460-6095.pdf

Nice to see hard data in these posts. Thanks!

Also, these articles make it clear that significant re-training of Porsche Techs is required so they understand the basics of battery-powered motor systems.

 

[whitex]

As an occasional FRC robot inspector I can state that level of resistance between the frame and battery is within the rules and I'd pass that robot. Though given an 800 volt instead of a 12 volt system the leakage would be under .2 watts. That would take about fifty years to drain a charged PB+.

Why do you think the odd 10K resistance? Is it because that is the top of the measurement range and battery is disconnected (so “plus” is interrupted by a contactor, leaving an open cirtcuit)?

 

[whitex]

WNT8 involved sending a VAL to Porsche then sending another to Porsche 50+ days later. It's quite possible they are looking for changes in the isolation resistance over time and using that as a proxy for moisture in the battery.

This so highlights the difference between Tesla and traditional car manufacturers. The values are already measured by the car’s electronics, why not collect them via OTA telemetry? At the very least you could deploy a piece of software to run periodically on the car (part of “ignition off” test for example) which could track the changes and trigger an in car warning to the driver to take the car in for service. Of course that would require OTA software deployment.

I get OTA is hard, but how does Porsche not see that it would save them a ton of money, therefore it is one of the more crucial pillars of modern automobiles? They should have developed proper OTA software update and telemetry by now. That said, having worked on automotive OTA, perhaps Tesla’s biggest advantage is Elon. Crazy or not, he is the dictator which makes decisions fast and keeps a unified vision. In my work I see such a mixture of different ideas being implemented, where each team or supplier has their own idea how to do things and will not budge, resulting in an patchwork of software which does not play well together.

 

[DougFrisk]

Why do you think the odd 10K resistance? Is it because that is the top of the measurement range and battery is disconnected (so “plus” is interrupted by a contactor, leaving an open cirtcuit)?

Probably. In theory, the Fluke meter I'm using in that photo can measure up to 50 megaohms. Compared to the other numbers the Taycan is showing 10 megaohms is a nice round number, so it's possible the hardware used in the Taycan caps out at something under that. Which makes sense because even the lowest 2 megaohm value is perfectly safe so there's no need for the hardware to be more sensitive.

 

[FencerGG]

My 2023 4s that i've had since last November just came up in the recall check officially (already thought it was in the range just have that extra validation now).

Honestly not sure what to do, really think if you do this recall it will likely take a really long time because even if the battery is unaffected I'm sure they still have to take apart a lot of stuff and reseal it all and even then I would be worried about how safe it is... the problem is I don't know what I would get if I got something else... love my taycan but there is nothing in the same price range that looks as sharp, drives as good, thoughts?

 

[DougFrisk]

My 2023 4s that i've had since last November just came up in the recall check officially (already thought it was in the range just have that extra validation now).

Honestly not sure what to do, really think if you do this recall it will likely take a really long time because even if the battery is unaffected I'm sure they still have to take apart a lot of stuff and reseal it all and even then I would be worried about how safe it is... the problem is I don't know what I would get if I got something else... love my taycan but there is nothing in the same price range that looks as sharp, drives as good, thoughts?

The car isn't unsafe to drive, if there is a fault with the sealant, you will get an electrical system failure warning long before there's a danger. That's assuming you don't spend a lot of time driving through axle deep water.

If I were in your position, I'd wait a few months and then schedule the inspection. It probably wont' take more than a day in the shop to do that testing. If it's one of the 3% that fails you are going to be at the mercy of new battery supply and may end up waiting months.

If not, the battery still has its full warranty and I wouldn't worry too much about the shop mechanics screwing up the battery seal.

 

[SergeyIndy]

My VIN was not in VIN range but in date range when it was earlier in the post but now I got notice from Carfax and these sites that I am under recall when entering my VIN. Not happy about it. I will study this more and this thread on what is next.

https://www.nhtsa.gov/recalls
https://recall.porsche.com/prod/pag/vinrecalllookup_V3.nsf/VIN?ReadForm&c=usa

 

[whitex]

My car just started showing the recall (when I logged into myPorsche). I already have a scheduled an appointment for next month for this and something else. At the time they told me a couple of hours for the battery test, but the tech also said they had not received the official procedure yet, so couple of hours was a guesstimate.

 

[pedroleumjelly]

Yup my car was not coming up in the vin checker last week but I got the notice on the Porsche app. Welp.

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