12 Volt Battery

[Windpower]

first question: in this situation should I attach a trickle charger (designed for a lithium battery) to my 12 volt battery?
second question: if I leave the main battery charged at say 85% will it survive the 6 months without draining itself?

I believe the Good to Know app says that, if you are not going to use the car for a long period of time, you should keep the 12v battery connected to a 'battery tender' and keep the car plugged into the EVSE.

The battery tender I have at home just for this purpose is a 'Noco Genius battery maintainer'. I haven't used it yet since I haven't made any multi week trips since Covid. But I plan to.

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[kort]

if you are going to use a trickle charger be certain that it is one that is compatible with the 12v in the taycan

 

[notfromtx]

I was just looking into this in prep for a one month period this summer, car will be in a warm garage.

The manual for my 22 says:

What do I want to do?
Lay up the vehicle if it is left unused for long periods.

What action do I need to take?

• If the vehicle is left for long periods in the garage or workshop, the doors, covers, and hood of the vehicle should be closed.
• Deactivate operational readiness.
• Connect the high-voltage battery to the power grid for trickle charging.

The battery will run down even if the vehicle is not in operation.

• To maintain its function, charge the battery approximately every 6 weeks or connect it to a trickle charger suitable for lithium batteries with a CC/CV or pure CV characteristic. Porsche recommends the charger and charge maintenance unit from Porsche Tequipment.

 

[Pozuelo]

I believe for those that are not going to be using their Taycan for an extended period, but have access to the car at least every month, I would leave the car unlocked (if it is safe to do so), around 50-60% battery charge and unplugged. Then at least every three weeks or 1 month, I would start the car, which charges the 12V battery and you can tell it has dropped its voltage, for 2-3 minutes. This will raise the voltage and then back to unlocked state. If the SOC drops below 40% ( which I doubt) I would plug in to raise to 60% and unplug. Repeat as necessary. 100% agree on over-inflating tires and limiting access thru the apps to the minimum.

 

[Dee]

I believe for those that are not going to be using their Taycan for an extended period, but have access to the car at least every month, I would leave the car unlocked (if it is safe to do so), around 50-60% battery charge and unplugged. Then at least every three weeks or 1 month, I would start the car, which charges the 12V battery and you can tell it has dropped its voltage, for 2-3 minutes. This will raise the voltage and then back to unlocked state. If the SOC drops below 40% ( which I doubt) I would plug in to raise to 60% and unplug. Repeat as necessary. 100% agree on over-inflating tires and limiting access thru the apps to the minimum.

And watch the 12V battery voltage.
If starting the car, look for this:
-If it's below 13,4V it's not charging and it'll soon die.
-If it's 13,4V you're ok.
-If it's over 13,4V it's charging and you're ok.

 

[Dee]

No 12V battery will drain just after a few weeks. I have a 10 year old Mini (4 year old 12V) and I can leave the car parked for 2 months with no issue lol.

A 12V battery on an EV is relatively small (cuz it doesn't have to crank a heavy starter motor).
Cuz of the remote nature of EVs it'll use more power when stationary.
So, it does drain the battery but if all is ok the HV battery should keep it on charge.
But then again, if you don't feel comfortable about it you can always use a trickle charger cuz when it dies on you you could end up with all kinds of unexpected problems...
Better safe than sorry if you are gonna store it for an extended period of time.

 

[kort]

I believe for those that are not going to be using their Taycan for an extended period, but have access to the car at least every month, I would leave the car unlocked (if it is safe to do so), around 50-60% battery charge and unplugged.

why unlocked? I have never heard of the door locking system having an sort of effect on the battery or SOC

 

[Pozuelo]

When the car is unlocked the alarm is inactive so you have less 12V battery consumption.

 

[Dave777]

These are the facts I have learned about the 12-volt battery:

1. The 12-volt battery is lithium-ion.
2. It does not interface with the larger battery that drives the car; in other words, the larger battery does not charge the 12-volt battery under any circumstances.
3. The 12-volt battery loses 1 1/2 percent of its charge each day the car is not driven.
4. If you store your Taycan for more than two weeks, you should attach a battery tender to the 12-volt battery.
5. The battery tender must be for a lithium-ion battery. Porsche and other brands sell battery tenders that service both regular and lithium-ion batteries. There is a switch on the tenders that you select for the type of battery you want to be charged.
6. The battery tender should be connected directly to your 12-volt battery, which is located in the front trunk. Do not connect the battery tender via the cigarette lighter; it will not work efficiently or at all.
7. The Porsche brand battery tender for lithium-ion batteries is expensive. You could purchase a tender for less money on Amazon: NOCO Genius 10 Battery Maintainer.

What Kinney posted is exactly what the Chief Tech at my Service Dept told me. He was very specific regarding the 2 week period. Also, important to monitor the voltage..it should never get down to 12v, should normally be 13.4v or better ..and should charge at 14.4v with a suitable Battery Maintainer. In addition to that, here is the latest ATI Bulletin 2003.1. Its the 3rd Revision to the first one that came out back in Oct 2020.
https://static.nhtsa.gov/odi/tsbs/2022/MC-10209809-0001.pdf

 

[Vercingetorix]

What Kinney posted is exactly what the Chief Tech at my Service Dept told me. He was very specific regarding the 2 week period. Also, important to monitor the voltage..it should never get down to 12v, should normally be 13.4v or better ..and should charge at 14.4v with a suitable Battery Maintainer. In addition to that, here is the latest ATI Bulletin 2003.1. Its the 3rd Revision to the first one that came out back in Oct 2020.
https://static.nhtsa.gov/odi/tsbs/2022/MC-10209809-0001.pdf

#2 is completely wrong. Per your link:
The Porsche Taycan is equipped with a 12-volt Lithium-Ion battery which is automatically charged and maintained by the High-Voltage (HV) traction battery and battery electronics.

 

[Dave777]

#2 is completely wrong. Per your link:
The Porsche Taycan is equipped with a 12-volt Lithium-Ion battery which is automatically charged and maintained by the High-Voltage (HV) traction battery and battery electronics.

Yes, when the car is being driven apparently.

 

[SDSoccerdad]

Yes, when the car is being driven apparently.

I was gone for 30 days. Received a call from Porsche Connect Support Services that my car was “sabotaged” - which could mean it lost its electrical charge. Car was at 50% SOC when we left. Came home today and the car was dead - nothing. Won’t even accept a charge from my PMCC - could the 12 volt lose its entire charge and nothing would turn on. When I mean nothing turns on - I mean nothing.

 

[Dave777]

What I’m interpreting….(and I most likely am wrong, because there seems to be so much confusion about this) is that when the car is being driven, the 12V battery is being “maintained “ by the main battery...thru programming and battery electronics.
-If the car is parked and powered off, only the 12v battery provides power for the door locks/alarms, MyPorsche logons etc. To me, this would explain the 12v battery voltage degradation while not being driven for 2 weeks or more. I notice the original Bulletin issued in 2020, was withdrawn in July2021, then reactivated in March2022.
So the earlier 12v battery issue still exists?
-..The confusing part in this bulletin is that it says to keep your main battery plugged in and kept to 50%, keep your key at least 30ft away and avoid prolonged use of the MyPorsche app. So that says to me, the main battery is NOT maintaining the 12v battery when the car is parked, whether plugged into an AC level2 charger or not...and to charge/maintain the 12v battery separately while parked/stored.
What’s hard to understand is why your main battery at 50% soc would lose power easily.
Apologies for any confusion..certainly an important topic to get a grip on .

 

[BigBob]

• Deactivate operational readiness.

What's that?

 

[whitex]

I am having an incredibly hard time wrapping my head around the fact that Porsche engineering, world famous, proud, rigorous German engineers, would design a car which cannot be parked at the airport for a couple of weeks without becoming an overpriced paperweight. Sure, first Tesla Roadsters has similar problems, but by the time Porsche decided to even think about the Taycan, they had Model S to play with and plenty of information on them on the internet. I've parked my Tesla Model S for a week or two at a time at the airport, including parking outdoors in winter temperatures (hard on battery, requires battery heater to work to keep the battery from freezing). Yea, the SoC went down as much as 1% a day (a bit more first couple of days, then less) when it was really cold, but the car (or its 12V battery) didn't die. Sure, I had to wait a minute or two for the car to bootup when I first got into it (after couple of days parking the car enters deep sleep mode to preserve the charge of the battery), and my power and regen was limited for the first few miles when the battery was cold, but I don't see it as a huge problem (still think it's better than arriving to a dead car).

Are German engineers too proud to learn from other companies' mistakes? Or are they suffering from "not invented here" syndrome and will not maintain the 12V battery on purpose purely because Tesla did it first? Something doesn't add up here. What happened here?

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