12V Battery Failure

[Will's Taycan]

I just purchased my2020 Taycan Turbo from a dealer in California two weeks ago, and after the second charge this weekend, the app showed 100% battery. I had left it charged for about 24 hours. So I went out to the garage to take the car out for some errands today. Unfortunately, the car had no power despite showing 100% power to the main battery. The charger plug would not unlock because the 12V battery is completely dead. Ironic that the 800V battery underneath is full but the 12 V is completely empty. I don't understand why this happened. The doors were fully closed and the lights were off. This may be a manufacturing defect. It seems easy enough to transfer energy from the main battery to the little one, but Porsche may not have addressed this with a software update. I found the manual pull cord in the driver door jamb to manually unlock the charger. It is at the top of the inside door jamb close to the charging port. It takes a good tug on the tab to get it started. Once it was disconnected, I tried to see if I could move it into neutral to push it out of the garage for towing, but it is impossible without power. It is stuck in the garage. It will require a tech to make a house call with a battery charger.

I know there is a fuse box in the driver footwell to enable recharging. However, when I tried something similar with my Ferrari 458, it caused extensive damage to sensitive electronics. I don't want to risk it with my new Taycan. I lobbed a call into the dealership this morning but I could not get a tech on the line. From reading Don's blog, I know that it requires a larger ion battery charging unit to initiate a charge in the footwell. Once it gets a little life back, the frunk can be opened to access the 12V battery directly. (Thank you Don!)

Does anyone know if there is a software update to prevent t his from happening again? I have found a number of Taycan owners that have had this same issue.

Will

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[Dee]

There is a major update available: WMA5 (and WMA7 for the Porsche charger).
Till then, look at the Good To Know app:

It's ok to put power on the terminal.
Not necessarily a charger, any 12V battery will do.

Cheers.

 

[JimBob]

If in doubt call Porsche Roadside assistance and let them fix it on their tab, provided you are not in too much of a rush. Also there are a bunch of instructions from Agero in the stickies as to how to handle this and some other issues.

 

[Will's Taycan]

Thanks for your assitance! I spoke with the GM at the dealer and he is sending a tech to charge the car and bring it back to the shop for the software update.

 

[daveo4EV]

https://www.taycanforum.com/forum/t...ttery-issue-and-electrical-system-error.3782/
https://www.taycanforum.com/forum/threads/12v-issue-strikes-another-one.4226/#post-58605
https://www.taycanforum.com/forum/threads/drained-12v-battery.3941/#post-54007
https://www.taycanforum.com/forum/threads/car-died-over-night….2525/
https://www.taycanforum.com/forum/threads/taycan-12v-drain-issues-caught-in-the-act.3729/
https://www.taycanforum.com/forum/threads/don-breaks-his-taycan-the-saga-of-the-12v-battery.1274/
https://www.taycanforum.com/forum/t...eath-and-the-chargers-theyre-hooked-too.2578/
https://www.taycanforum.com/forum/threads/12-volt-battery-issue-now.3559/
https://www.taycanforum.com/forum/threads/12v-battery-dead.3131/
https://www.taycanforum.com/forum/threads/12-volt-dead-battery-poll.2688/
https://www.taycanforum.com/forum/t...lectrical-system-error.3782/page-4#post-53664
https://www.taycanforum.com/forum/t...it-dies-because-of-the-12-volt-problem….2529/

https://www.taycanforum.com/forum/t...it-dies-because-of-the-12-volt-problem….2529/

 

[Doc B]

Just been noticing charging behaviour on my 2020 Taycan after the recent WMA5 up-date. If the car is trickle charging on solar power, when the Sun goes behind a cloud, and so the EV charger (Zappi) stops charging the car, the car charging port initially starts flashing white. After about a minute or two, it then turns red (charging error), and finally, after another minute or two, goes to sleep (light switches off). If the Sun comes back out while the car is in the white light flashing stage, or after the car has gone to sleep, the car will start charging again. However, if it happens while the car is in the red light phase, the EV charger can not start charging the car, and the car blocks the charger from charging the car at all, until I have pressed the car port button again. Annoying, since I solar charge a lot - never had a charging error pre October 2020 up-date, then started having them occasionally, and not after the April 2021 up-date have them all the time. However, I wonder whether this protocol has been introduced/revised to protect against 12V battery issues - i.e. the car instigates a red charging error / block of the EV charger if power from the charger goes dead for a while, then puts the car to sleep. I am speculating that in the past, the car would stay awake, draining the 12V battery even though the EV charger has finished charging the car. Just a thought. Totally unsubstantiated by any evidence or real knowledge of what's going on (perhaps I should have said that at the start so you did not waste your time reading this).

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