J1.2 - "12 Volt battery low" message

[ct4s]

Damn - got home tonight and saw the dreaded "12 Volt battery low" message.
J1.2 4s ST.
Main battery was on 75% charge.
Most driving is 6 mile commutes with the odd 30 miler each week or two.

Called Porsche Assist but it's out of hours so there was no specialist to take the call and the Porsche dealership is closed.
Assist is sending someone to look at it tonight, but suspect they'll not be able to do anything. Hope I'm wrong.

Bad timing - I have a 300+ mile journey over the next 2 days with an early start tomorrow.
Would a long drive help fix it? Would you risk it? Or, am I doomed?

I have a CTEK CS ONE which can charge lithium batteries. I'll see if Assist think it's worth trying.

Noticed a few minor niggles in the past several days and it was due to go to Porsche in a few weeks to have the software checked.
Heated seats kept turning off unless i was driving, windows wouldn't demist unless I was driving, tonight the welcome home lights didn't work when I unlocked / locked the doors and comfort access didn't work. Likely they all use the 12v electrics.

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[trycan]

Unable to say if you'll be safe for the upcoming roadtrip, but I would put your charger on the 12V and get it up to full. Would be strange if your J1.2 little battery was toast already.

 

[W1NGE]

Damn - got home tonight and saw the dreaded "12 Volt battery low" message.
J1.2 4s ST.
Main battery was on 75% charge.
Most driving is 6 mile commutes with the odd 30 miler each week or two.

Called Porsche Assist but it's out of hours so there was no specialist to take the call and the Porsche dealership is closed.
Assist is sending someone to look at it tonight, but suspect they'll not be able to do anything. Hope I'm wrong.

Bad timing - I have a 300+ mile journey over the next 2 days with an early start tomorrow.
Would a long drive help fix it? Would you risk it? Or, am I doomed?

I have a CTEK CS ONE which can charge lithium batteries. I'll see if Assist think it's worth trying.

Noticed a few minor niggles in the past several days and it was due to go to Porsche in a few weeks to have the software checked.
Heated seats kept turning off unless i was driving, windows wouldn't demist unless I was driving, tonight the welcome home lights didn't work when I unlocked / locked the doors and comfort access didn't work. Likely they all use the 12v electrics.

Most are 12v but the heater is HV and so uses the main HV battery.

Use your CTEK charger to trickle charge the 12v.

HV should also provide charge when needed.

Could be symptomatic of a failing 12v unfortunately.

 

[ct4s]

Yep - i think it's toast too.
I just need it to not be toasted until Sat.
Dropping a new battery in should be easy for Porsche to do under warranty

 

[whitex]

Yep - i think it's toast too.
I just need it to not be toasted until Sat.
Dropping a new battery in should be easy for Porsche to do under warranty

Perhaps lookup how to enter the car with failed 12V, and carry with you a charged 12V bootster (one of those Lithium Ion packs which can jumpstart a car) - just in case you run into an issue in the field before you have the dealer fix it.

 

[ct4s]

Assist now delayed a few hours.
HV battery is charging and I'll add the cteck to the LV battery.

Depending on what Assist tell me, I'll give it a try tomorrow unless the warning is still present before I drive off.

Hope it's just a LV issue. But doubt that would fail by itself.
My best guess so far is it could be more serious, such as the DC-DC converter.

 

[ct4s]

Perhaps lookup how to enter the car with failed 12V, and carry with you a charged 12V bootster (one of those Lithium Ion packs which can jumpstart a car) - just in case you run into an issue in the field before you have the dealer fix it.

Good idea, but I don't have one.

 

[whitex]

Good idea, but I don't have one.

They is a myriad of them available starting at ~$50 in the US. Also useful if you want to help jump start someone else's car (being rechargeable and therefore wireless).

 

[prj]

Booster would be my bet also, if you're getting that message during normal use something's toast in the car. It's not like it's been sat for a long time.
Trickle charger not going to help you there - if the main charger with a-lot-of-amps can't keep it operational, then the trickle charger will be a waste of time.

Try to get one of those lithium boosters, I've used these in the past:
https://no.co/boost/boost
Also familiarize yourself with the procedure to pop the frunk/hood when there's no battery! Should be in the owners manual. With the booster you at least shouldn't get stranded, unless it's the DC-DC going bad, in which case nothing other than replacement of it will help.

 

[Tooney]

Does your car have a dashcam or any other add-on device that consumes power?

 

[prj]

Does your car have a dashcam or any other add-on device that consumes power?

It turns on the DC-DC whenever the 12V battery capacity drops below 8 Ah and tops it up.
You can't drain the 12V battery on a Taycan with accessories unless the HV battery is empty.

 

[whitex]

It turns on the DC-DC whenever the 12V battery capacity drops below 8 Ah and tops it up.
You can't drain the 12V battery on a Taycan with accessories unless the HV battery is empty.

I can confirm, have been running a 2 channel dashcam 24/7, left car at the airport for up to 2 weeks, never had any 12V issues.

 

[Tooney]

I can confirm, have been running a 2 channel dashcam 24/7, left car at the airport for up to 2 weeks, never had any 12V issues.

Yeah your car only has heating issues maybe they need to check that dashcam.

 

[Tooney]

It turns on the DC-DC whenever the 12V battery capacity drops below 8 Ah and tops it up.
You can't drain the 12V battery on a Taycan with accessories unless the HV battery is empty.

That's a good point. But, if his Taycan is giving a 12v battery low message, isn't that a sign that something (perhaps the auto 'tops it up' feature) may not be working properly?

 

[W1NGE]

Assist now delayed a few hours.
HV battery is charging and I'll add the cteck to the LV battery.

Depending on what Assist tell me, I'll give it a try tomorrow unless the warning is still present before I drive off.

Hope it's just a LV issue. But doubt that would fail by itself.
My best guess so far is it could be more serious, such as the DC-DC converter.

Hmm not sure that's the reason.

Historically there have been issues with 12v Li-ion Taycan batteries (J1.1) from the OEM (software related I think). At.that time getting a replacement wasn't straightforward hopefully those supply issues no longer exist.

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