12 Volt Battery

[John Cronin]

Received my Taycan 6 weeks ago. today had to call out Porsche assistance as I could not open my car the remote would not open the doors. The roadside assistance found that my 12 volt battery was flat as I had not used the car in 10/14 days. He got it going again and said that I need to use the car every 3 days or so to keep it charged. or buy a trickle charger to keep the battery positive. my question why haven't Porsche provided a convertor from the main car battery to provide a trickle charge to the 12 volt battery.

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[XLR82XS]

The 12V is charged via the HV battery when needed. Lots of threads here on this topic. This info is also in the owners manual.

 

[raharris]

What charge was your main battery at?

 

[KTC]

The 12V is charged via the HV battery when needed. Lots of threads here on this topic. This info is also in the owners manual.

And not when the car is off, correct?

 

[John Cronin]

What charge was your main battery at?

90%

 

[wemct]

When I first received my Taycan in April 2020, I was nervous about the 12V battery maintaining its charge when the car sat in the garage for 2 weeks periods. I used a trickle charger for lithium batteries. After the big software updates that are discussed at length in the forum, I stopped using the trickle charger without any problems. Currently the Taycan is the Northeast US, parked outdoors in freezing temperatures. I returned last night after being away for 2 weeks. The car started without any issue. I even preheated the car for an hour at 7am without any issues with the 12V battery. You absolutely do NOT need to start/use the car every 3 days.

 

[kort]

Received my Taycan 6 weeks ago. today had to call out Porsche assistance as I could not open my car the remote would not open the doors. The roadside assistance found that my 12 volt battery was flat as I had not used the car in 10/14 days. He got it going again and said that I need to use the car every 3 days or so to keep it charged. or buy a trickle charger to keep the battery positive. my question why haven't Porsche provided a convertor from the main car battery to provide a trickle charge to the 12 volt battery.

I call nonsense on the advice that you were given, I leave my car sitting for days/weeks at a time with no such issues.

 

[iamfrozt]

I call nonsense on the advice that you were given, I leave my car sitting for days/weeks at a time with no such issues.

I agree. My car just sat for a week because my kid was on christmas break and I have no reason to drive around otherwise when I'm not taking him to/from school. Car has been fine and started with zero issues today and had a charge.

My carplay didn't want to work all the sudden today when I took him back to school, but that's obviously unrelated and a minor complaint

 

[John Cronin]

A few points to make here:

1. It is not recommended to connect to a trickle charger by the manufacturer. Trickle charging a lithium battery is risky and could present a fire hazard.
2. What year is your Taycan? Perhaps your car should have received the 12v battery software fix.
3. If 2 above is not relevant, it could be a bad 12v battery. It has been known to happen.
4. Are you connecting any accessories that are on all the time?

I have left my Taycan for as long as three weeks with no battery issues.

Thanks for the feedback

My car is brand new November 2021 and classed as a 2022 version. I do not have any accessories connected to the car

 

[Vercingetorix]

The manual:

 

[Vercingetorix]

Part 2:

 

[Kinney]

Received my Taycan 6 weeks ago. today had to call out Porsche assistance as I could not open my car the remote would not open the doors. The roadside assistance found that my 12 volt battery was flat as I had not used the car in 10/14 days. He got it going again and said that I need to use the car every 3 days or so to keep it charged. or buy a trickle charger to keep the battery positive. my question why haven't Porsche provided a convertor from the main car battery to provide a trickle charge to the 12 volt battery.

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.

 

[Vercingetorix]

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.

So what charges the 12V battery? You realize most of the electrical system other than the traction battery and motors run off 12v right?

 

[Dee]

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

1. 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.
2. If you store your Taycan for more than two weeks, you should attach a battery tender to the 12-volt battery.

These "facts" are wrong.
I presume you misunderstood.

 

[Windpower]

I've had my Taycan for about three months. A month ago I 'lost' the 12v battery and needed to get the car jump started. This week I brought my car in for the WNA5 software update. When I picked up my car, I spoke with the service advisor and we discussed the problem I had with the 12v battery. He said that as part of the WNA5 update there was a software change which should prevent the car, in some cases, from continuing to use 12v power immediately after a charging session. It turns out that when I lost the 12v battery, it was three days after I had charged to 85% but then parked without using the car. So maybe my car was affected by this 'bug'.

Lets hope the WNA5 update has fixed the 12v problem permanently.

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