Should I be worried? (12V battery question)

[Fedex77]

So I can’t remember if the battery meter was full when I took delivery but the meter is now at 75%…is this an indication that the battery isn’t charging enough?

(2021 Taycan 4S presumably with all the latest updates)

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[chrisk]

13.4V is normal. When the car is off for a while it drops to 12.x but once you start the car it goes back to 13.4V after a few seconds and that is the normal operating voltage.

 

[r553]

You are driving the car so the main battery will discharge and is what is shown on the display.

 

[tigerbalm]

So I can’t remember if the battery meter was full when I took delivery but the meter is now at 75%…is this an indication that the battery isn’t charging enough?

That is showing voltage, not state of charge of the 12V battery.

 

[JimBob]

If you refer to your screen shot.

There are two batteries.

The high voltage battery used to drive the electric motors. Its capacity is measure in kilo Watt hours (kWh) In this case the 100% says the high voltage battery is fully charged. When it read 75% you had used 25% of the charge in the battery. You set the charging parameters in the car display for this battery. Porsche has recommendations for the settings that will best preserve its life.

The 12 volt battery is used to power the 12 volt systems in the car such as the display. It will almost read around 13.4 volts. It is charged automatically by the high voltage capacity.

Based on your description there is nothing wrong with either the high voltage battery or the low voltage battery.

 

[Fedex77]

Thanks all! I was just worried because the blue bar on the 12V system wasn’t at “full”

 

[new2porsche]

Is there any reason to have the 12v battery’s status displayed all of the time?

 

[tchavei]

Is there any reason to have the 12v battery’s status displayed all of the time?

Not really unless you have a dashcam recording 24/7. Then the indication might help you diagnose early a potential issue (like the main battery not charging the 12v when needed, etc) but generally you don't "need" to see it all the time.

Same could be argued about "Do we really need 3 instances of the clock (dash, pcm and crono) displayed simultanely?"

 

[axpy]

The voltage you see is not the battery voltage but the voltage of the auxiliary system. When the car is not powered, this is basically the battery voltage (minus the voltage drop from current draw). While in operation, the voltage is regulated by the DC/DC converter pulling from the main battery (and recharging the 12V battery at the same time). The aux power is important because everything but the drivetrain so if anything behave abnormally in the car the first thing you want to know is if electrical components are appropriately powered.

And ladies and gentlemen is how we end up with fake gauge in modern cars.

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