Cheat sheet: How do I recover my Taycan if it dies because of the 12 volt problem…

[farazkhu2]

there is no reason to believe this is a “build/manufacturing” issue - or even a model-year issue - it’s a fault with the core software management of all Taycan’s - the only reason you may get away with this line of thinking is that there is a new software update being applied to all Taycan’s that Prosche claims fixes some known 12V issues - there is however no way to tell if it fixes _ALL_ 12V issues…

but to date it’s very very unlikely this issue has anything to do with “how early“ you are in the manufacturing process - it’s an operating system issue which is common to all vehicles.

I hope so, I know two 4S owners and neither have mentioned any issues so far, they have their vehicles for 8 months now. Anyways, lets see if the update really did fix it or not, we will find out in coming months.

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[farazkhu2]

Problem is, there is minimal experience with electric cars at Porsche so every issue seems to be a new one for them. I just brought my connect charger with a melted plug into the dealership and neither the service advisor or manager knew what to do about it. I was told a new one has to be ordered from Germany and they are not sure if it would be covered by warranty. In the meantime my car is useless because I have no way of charging it (and I'm somewhat concerned that it could burn my house down if the issue wasn't addressed with the latest update that was done on the charger). Pretty wild.

Are there any aftermarket products? that sounds ridiculous that they have to order a charger from Germany. It could take weeks, what about the charger at the dealership? they should let you use it until this issue is resolved.

 

[cgfrndpor]

Are there any aftermarket products? that sounds ridiculous that they have to order a charger from Germany. It could take weeks, what about the charger at the dealership? they should let you use it until this issue is resolved.

There are many chargers for wall mounting on the market that will work with the car.

 

[daveo4EV]

to be clear it’s unproven this will make a different - move 12V chargers are very low power- and the problem is the car is draining the 12V with high demand (demand unlikely to be offset by a normal 12V trickle charger) - and once the battery is offline it’s isolated behind a power relay - the only way to recover the vehicle once it’s in this state is to apply a high power 12V source to reboot the vehicle’s main computer - which then recovers the vehicle and will charge the 12V battery from the main 800V battery - also to date the problem only occurs while the vehicle is plugged into AC power to charge the vehicle - it’s happend on MY’20 & MY’21 vehicles and has happened across the range of model trims…

 

[daveo4EV]

I hope so, I know two 4S owners and neither have mentioned any issues so far, they have their vehicles for 8 months now. Anyways, lets see if the update really did fix it or not, we will find out in coming months.

it’s always been a low reproducibility issue and it strikes randomly - the fact that is has not occured doesn’t mean it won’t occur - I’ve owned my Taycan since July 2020 - and it’s happend 1 1/2 times to me - but only those ~2 times…

the new software update is promising in this space, but it will take some time to see if Porsche has eradicated the issue…time will tell.

 

[Drew Webb]

Just wanted to report a continuing 12V battery issue even after the latest software updates. My MY21 4S was not.in my home garage with 50% SOC an was not used for a week. It was not connected to the home charger and was locked. Suddenly dead one morning after never having had this problem since delivery in January 2021. I used the wake up protocol published on this forum to open the drunk and then used a NOCO GB40 to shock the 12v terminals with a boost. Car came right back as predicted. and interestingly showed 13.6v charge on the instrument cluster right disc that I have populated with both batteries SOC.
In future I plan to put the car on a trickle charger (Porsche model with Li-ion mode) if left unattended for more than a week as a precaution against this hassle. I’m also concerned about repeated use of the NOCO booster that according to the manufacturer manual should NOT be used with Li-ion batteries. Anyone else bothered by this?

 

[daveo4EV]

Just wanted to report a continuing 12V battery issue even after the latest software updates. My MY21 4S was not.in my home garage with 50% SOC an was not used for a week. It was not connected to the home charger and was locked. Suddenly dead one morning after never having had this problem since delivery in January 2021. I used the wake up protocol published on this forum to open the drunk and then used a NOCO GB40 to shock the 12v terminals with a boost. Car came right back as predicted. and interestingly showed 13.6v charge on the instrument cluster right disc that I have populated with both batteries SOC.
In future I plan to put the car on a trickle charger (Porsche model with Li-ion mode) if left unattended for more than a week as a precaution against this hassle. I’m also concerned about repeated use of the NOCO booster that according to the manufacturer manual should NOT be used with Li-ion batteries. Anyone else bothered by this?

I'm unconcerned about using the Booster - since you are _NOT_ jumping the vehicle's 12V LiON battery via this method - you are providing 12-15V of power directly to the main computer on the vehicle's main power bus - which wakes up the vehicle's main computer which then initiates vehicle "start up" - unless you leave the NOCO device attached for a long time after that occurs you are not actually powering the LiON 12V battery - so it's just raw electricity on the bus which should not damage anything.

this is vs jump starting an ICE vehicle via jumping the battery directly where power flow "through" the 12V battery to the ICE starter - power in this case does not flow "through" the Taycan's 12V battery - it's just directly powering the main 12V energy-bus to provide power to the main computer.

 

[farazkhu2]

I'm unconcerned about using the Booster - since you are _NOT_ jumping the vehicle's 12V LiON battery via this method - you are providing 12-15V of power directly to the main computer on the vehicle's main power bus - which wakes up the vehicle's main computer which then initiates vehicle "start up" - unless you leave the NOCO device attached for a long time after that occurs you are not actually powering the LiON 12V battery - so it's just raw electricity on the bus which should not damage anything.

this is vs jump starting an ICE vehicle via jumping the battery directly where power flow "through" the 12V battery to the ICE starter - power in this case does not flow "through" the Taycan's 12V battery - it's just directly powering the main 12V energy-bus to provide power to the main computer.

That is interesting, i left mine for 10 days and it turned on without any issue..Now, I am concern to leave it at the airport. Wonder if there is anything we can do diffrently...this is so random.

 

[chrisk]

FYI Porsche published a TSB last month advising against the usage of boosters like NOCO to jump the 12v battery because they might catch fire.

https://static.nhtsa.gov/odi/tsbs/2021/MC-10202969-0001.pdf

 

[Drew Webb]

OK now I’m even more spooked given the TSB @chrisk alerted us to from Porsche! What do we do now? Carry a 10lb lead acid battery that can leak around in the back seat? I guess I’ll opt for the trickle charger to keep my $150k fun-mobile road-ready until Porsche gets it’s act together on this frustrating issue.

 

[Vercingetorix]

Hook one of these up to your lithium jump pack? It’s a 2 amp 12v to 12v charger. May have to wait a few minutes for the battery to charge. Will have to use manual override on the GB40.
https://optimate1.com/wp-content/uploads//2021/03/TM500_V3-IN1-191028.pdf

 

[daveo4EV]

if the battery is “dead/low” it will NOT charge because it’s behind a tripped “relay” - hooking up the taycan’s jumping post will _NOT_ charge the battery unless you provide enough power to boot/power the main vehicle computer - only then will the 12V battery’s relay be reset and it can begin recieving “power” - however by then it will be charged by the “big” 800V battery via onboard DC/DC voltage converters…

not sure how low amp 12V trickle chargers do us any good.

 

[Vercingetorix]

if the battery is “dead/low” it will NOT charge because it’s behind a tripped “relay” - hooking up the taycan’s jumping post will _NOT_ charge the battery unless you provide enough power to boot/power the main vehicle computer - only then will the 12V battery’s relay be reset and it can begin recieving “power” - however by then it will be charged by the “big” 800V battery via onboard DC/DC voltage converters…

not sure how low amp 12V trickle chargers do us any good.

Read the webpage. It has a pulse for BMS disconnects.

 

[Drew Webb]

Reading Optimate webpage it seems that some of their models have what appears to be a BMS boost button. Would these models substitute for the GB40 and obviate the need to connect the units in series?

 

[Snorlax]

Hi all, been following this issue for some time. This seems to be the most updated thread. So Porsche has not yet identified the problem/come out with a solution?

I do not own a Taycan but just received my e-tron GT. Some owners on the e-tron forums have been experiencing similar 12v drain issues rendering the car a brick. In our case, it is even worse, as there does not seem to be any way to manually open the frunk to allow access to the 12v charging posts (the frunk release lever requires power!)

At least on the Taycan you can get to those charge posts with the 12v being dead.

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