How can remotely force my Taycan 4S 2020 to charge the 12V battery?

[prj]

I also left the frunk open on mine just in case when I left it for 7 weeks, but had zero issues, it just fired up.

Sponsored

 

[69Mach390]

These 12V li-ion batteries last very long cuz they're not stressed like a 12V battery of an ICE (high amps due to starter motor).

Sometimes. But there are plenty of threads here telling us how much it costs to replace one, so they still can die.

Either way, he didn’t answer the question as to if it needed to be replaced or just charged.

 

[Scandinavian]

I edited the post a little bit with latest info, I did locate the relevant portion in the J1.2 manual.
I think the way it is worded is also somewhat confusing. The TSB is not much clearer.

https://static.nhtsa.gov/odi/tsbs/2022/MC-10209809-0001.pdf

They even say themselves:

What I gather from it, is that if it is parked for longer than 8 weeks, and not connected to the AC charger, then you might need to charge the 12V battery separately.

I didn't quite hit the 8 weeks on mine, was 7 or so.
But most issues here seem to be not from leaving it for a long time, rather people have 12V malfunctions after less than a week, which indicates a different cause.

Either way - the way the TSB is worded indicates that you should not have any issues with the 12V battery for a minimum of 8 weeks even if you don't connect anything at all. So those with 12V battery issues should first ask the question:
Has the car been unused for 8 weeks or more?

If the answer is "no", then something is faulty.

I volunteer as a test case now!
I had only planned to leave the car for just 3 weeks at home. But a change of plans has now resulted in the car being left for 9 weeks until we return to our home in January. Since the weather forecast when we left, warned for some severe thunderstorms a few days later, I did not plug in the AC in the car, nor connect any12 volt trickle charger. And a mother of thunderstorms occurred and knocked out all electricity for a few hours as predicted.

I know for sure that the car still was online for 2 weeks and a bit, but I had cancelled my Porsche Connect and after that I have had no contact with the car.

So hopefully the updated software in the car will ensure that the 12 volt battery will stay charged. Else I need to follow the procedure with reserve key and booster etc.
Will let you know mid January!

Happy New Year!

 

[prj]

So hopefully the updated software in the car will ensure that the 12 volt battery will stay charged. Else I need to follow the procedure with reserve key and booster etc.
Will let you know mid January!

Happy New Year!

I hope so too - at least I did not have any issues on my J1.1 after leaving it for 7 weeks last summer.

 

[f1eng]

Mine died when I left the car 5 months. People tell me that’s not possible, but it happened. The car was charging when the 12 volt died. It supposed to charge the 12 volt but it didn’t. 2021 model.

Mine died when I left it for 8 days...

 

[f1eng]

Now that the car is 5 years old, are you sure the 12v didn’t just go bad?

Or was it fine when you charged it again?

Lead acid 12V batteries last about 5 to 6 years but Lithium could be good for 20.

 

[prj]

Mine died when I left it for 8 days...

100% something faulty, as I left mine for over 40 days without issues.

Lead acid 12V batteries last about 5 to 6 years but Lithium could be good for 20.

As long as they're not made by LG CHEM

 

[f1eng]

100% something faulty, as I left mine for over 40 days without issues.


As long as they're not made by LG CHEM

As it turned out the first time I needed to use it after Christmas last year was to take it in for its first service, which had to be delayed a few hours while I got the car going.
It was reported to the dealer (obviously) but diagnostics showed no faults, though it could be the diagnostics memory was empty, they weren't clear on that.
I must say I have always been suspicious I may have battery problems since mine was one of the cars which waited in storage for months after being build due to a shortage of 12V batteries.
I was most concerned the main traction battery had just been sitting there but also that the first batch of 12V batteries to arrive may be hurriedly QC'd.

 

[kurand]

12V battery in my MY2023 Taycan RWD behaves badly at this time of year each year I‘ve owned the car. It seems that some other folks also have similarly misbehaving 12V batteries as the number of reports on the forum always increases at this time of year.

First year, it died while I was away on holiday for a week, so had to call out Porsche Assistance/AA to get the car going again in the Heathrow carpark after a 12 hour flight.

Second year, It died in my garage after getting back from a longish trip. Called Porsche Assistance/AA again and they got it going and the booked it into the OPC for investigation - no problem found with muttering of failed OTA update …

This year, it started reporting low 12V battery just before I left for a longish trip late December from UK to Charente-Maritime department of France.

These days, If I see the low battery message, I put the 12V battery on a charger and start leaving the frunk unlatched for easy access. Also have an external 12V power pack (usually used for may sprint car) ready to kick the LiFePo battery back to life if it shuts down.

I really didn’t expect this kind of behaviour from a modern Porsche.

 

[prj]

I really didn’t expect this kind of behaviour from a modern Porsche.

And you shouldn't - there is clearly something defective on your car and Porsche should fix it. Whether it is the battery itself or some other issue.

 

[eddieterry]

I have had the same problem each winter with Porsche finding no faults in either software or 12 Volt. However I have had Porsche Tonbridge phone me last week to ask me to arrange for car to go back in as Porsche have an update for the 12 Volt software for my year (2023). It goes in on 23 January so will update if this new update solves the problem.

 

[prj]

Btw unlike your warm island climate the temperature goes here down as far as -20C in the winter and I had exactly zero issues with the 12V last winter...

Sounds to me more and more that just like on a huge amount of Cayennes, there is a massive bad batch of bad batteries on the Taycans as well, just on the ICE it shows much quicker, as it has no facility to top the battery up with the engine off.

Essentially the way you are describing it points to the fact that the battery capacity has significantly degraded to the point it's almost non-existent, same like a really old lead-acid battery.

 

[eddieterry]

You are probably correct but each time Porsche has completed an in depth check on the 12 Volt they have found it to be fine. Obviously it is either a software or hardware problem. Lets hope this latest update to the 12 Volt switch software / firmware sorts it - they say it is specific to my year and comes from Porsche Germany.

 

[kurand]

Mine too - they never find anything wrong with the battery. It will be interesting to see if PRG Reading contact me for this 12V software update. Either way, come March at the latest, I am out of this particular car so I am not sure I can be bothered with yet another service appointment.

 

[69Mach390]

Lead acid 12V batteries last about 5 to 6 years but Lithium could be good for 20.

Could be. But they also can die within a year.

But I’ll buy a beer for the first guy who gets their 12v battery to last 20 years in Florida. Your 12v doesn’t get the same type of temperature and charge treatment as your high voltage battery.

Sponsored