Drained 12v battery

[Freakzilla9]

are you sure this one is the one to buy?

from their site
The GB40 is for jump starting 12-volt lead-acid batteries only

you scared me for a moment
I double checked

I can charge the hv battery , the problem is after I give the jump start I see the volt of the 12v battery goes up till 14.7v,once I start driving the car the volt goes down very fast till it reaches the safety cut off point and the electrical system error messages appear..
The first point you said to turn on the car so the dc dc charges the 12v battery,I did that but in small time like after one minute the car sleeps and disconnects everything after saying the 12v battery low press power button or connect charging plug..
Also after my first time giving it a jump start,I drove it about 300km from the port to my house but it didn’t charge the car from the hv battery..
I went to Bridgestone and they measured the 12v battery volt and the device said it’s dead battery,I think the 12v battery is deeply discharged so the safety relay is not opening..
Do you think if I put it on a specific lifepo4 battery charger will help to pass the Critical point and the relay opens and accepts charging? Or the 12v battery is damaged ?
Thanks

you can try another thing . Buy Porsche 12v charger which is called

 

[Freakzilla9]

I can charge the hv battery , the problem is after I give the jump start I see the volt of the 12v battery goes up till 14.7v,once I start driving the car the volt goes down very fast till it reaches the safety cut off point and the electrical system error messages appear..
The first point you said to turn on the car so the dc dc charges the 12v battery,I did that but in small time like after one minute the car sleeps and disconnects everything after saying the 12v battery low press power button or connect charging plug..
Also after my first time giving it a jump start,I drove it about 300km from the port to my house but it didn’t charge the car from the hv battery..
I went to Bridgestone and they measured the 12v battery volt and the device said it’s dead battery,I think the 12v battery is deeply discharged so the safety relay is not opening..
Do you think if I put it on a specific lifepo4 battery charger will help to pass the Critical point and the relay opens and accepts charging? Or the 12v battery is damaged ?
Thanks

You can do another thing which is buy a Porsche 12v charger From their official website

it’s called Porsche charge o mat pro
Connect it and leave it charging to a long period like 2-3 days

hopefully hopefully that will charge your 12v battery

 

[kort]

you scared me for a moment
I double checked

one of us is confused, the way I see it is that the noco unit IS A LITHIUM unit however according to their specs it is to be used only on lead acid batteries.
see page 5 of their user guide, note the caution part
https://no.co/media/nocodownloads/format/g/b/gb40_v3_userguide_01.11.2019_web_1.pdf

 

[daveo4EV]

sounds like your 12V battery is bad - you’ll need to work with porsche replace it or diagnose it - also porsche specifically states not to use their battery tender with the taycan

12V battery tenders will not do what you think they will do with an EV and may not even work.

you’re goign to need to work with Porsche to diagnose what’s wrong with your vehicle.

if you don’t have a porsche dealer might I suggest getting a 1st generation ev vehicle with out any factory support near by is goig to make thing difficult - there is inevitably going to be some problems with new products like this that only the dealer can diagnose.

 

[Freakzilla9]

one of us is confused, the way I see it is that the noco unit IS A LITHIUM unit however according to their specs it is to be used only on lead acid batteries.
see page 5 of their user guide, note the caution part
https://no.co/media/nocodownloads/format/g/b/gb40_v3_userguide_01.11.2019_web_1.pdf

Hmm I guess your right and I purchased a wrong item unfortunately . To make it double sure just in case I have emailed the support team at noco
Let’s see

thanks for this
Lucky not to have used it on the Taycan

 

[Iben]

I reckon you could use the Noco GB40, because first you use it to open the Frunk (spare key, open door and power to open Frunk).
Then you jump start the LiFePO4 battery, so the car comes to life and take over the charging.
The LiFePO4 battery isn't empty, just shut off (safety).

There can't be much difference using GB40 vs an ordinary car battery?

 

[kort]

I reckon you could use the Noco GB40, because first you use it to open the Frunk (spare key, open door and power to open Frunk).
Then you jump start the LiFePO4 battery, so the car comes to life and take over the charging.
The LiFePO4 battery isn't empty, just shut off (safety).

There can't be much difference using GB40 vs an ordinary car battery?

other than the fact that the manufacturer specifically states that the unit should not be used on a lithium ion battery?
I would advise purchasing the porsche charge o mat pro
https://shop.porscheusa.com/porsche...ies/porsche_charge_o_mat_pro_95804490071.html

 

[NC_Taycan]

I can charge the hv battery , the problem is after I give the jump start I see the volt of the 12v battery goes up till 14.7v,once I start driving the car the volt goes down very fast till it reaches the safety cut off point and the electrical system error messages appear..
The first point you said to turn on the car so the dc dc charges the 12v battery,I did that but in small time like after one minute the car sleeps and disconnects everything after saying the 12v battery low press power button or connect charging plug..
Also after my first time giving it a jump start,I drove it about 300km from the port to my house but it didn’t charge the car from the hv battery..
I went to Bridgestone and they measured the 12v battery volt and the device said it’s dead battery,I think the 12v battery is deeply discharged so the safety relay is not opening..
Do you think if I put it on a specific lifepo4 battery charger will help to pass the Critical point and the relay opens and accepts charging? Or the 12v battery is damaged ?
Thanks

This first sentence is very concerning and could indicate a problem with the DC-DC converter that charges the 12V battery from the HV battery. If indeed this DC-DC converter is bad, you won't be able to do much of anything - charge, or drive - since the 12V system is needed for the rest of the car to work. You may or may not also have a bad 12V battery, however I am more inclined to guess bad DC-DC converter since the DC-DC converter generates 12V system power while the HV battery is engaged - and you aren't seeing that happen (your first sentence). Conversely, you were able to drive it 300km and that would not be possible with a failed DC-DC converter. Maybe it's failed since that drive. Unfortunately I fear this is a problem that you won't be able to solve on your own, and this is especially troublesome for you because I believe you said you have no dealer...

 

[Saadaboelwafa]

This first sentence is very concerning and could indicate a problem with the DC-DC converter that charges the 12V battery from the HV battery. If indeed this DC-DC converter is bad, you won't be able to do much of anything - charge, or drive - since the 12V system is needed for the rest of the car to work. You may or may not also have a bad 12V battery, however I am more inclined to guess bad DC-DC converter since the DC-DC converter generates 12V system power while the HV battery is engaged - and you aren't seeing that happen (your first sentence). Conversely, you were able to drive it 300km and that would not be possible with a failed DC-DC converter. Maybe it's failed since that drive. Unfortunately I fear this is a problem that you won't be able to solve on your own, and this is especially troublesome for you because I believe you said you have no dealer...

I guess the dc dc converter is working because every time I give a jump start with an external battery I can drive the car without any problem except that red message saying electrical system fault due to the weak 12v battery..
Do you think that if the 12v battery is totally drained needs special charger to wake up again and accept charging?

 

[Saadaboelwafa]

This first sentence is very concerning and could indicate a problem with the DC-DC converter that charges the 12V battery from the HV battery. If indeed this DC-DC converter is bad, you won't be able to do much of anything - charge, or drive - since the 12V system is needed for the rest of the car to work. You may or may not also have a bad 12V battery, however I am more inclined to guess bad DC-DC converter since the DC-DC converter generates 12V system power while the HV battery is engaged - and you aren't seeing that happen (your first sentence). Conversely, you were able to drive it 300km and that would not be possible with a failed DC-DC converter. Maybe it's failed since that drive. Unfortunately I fear this is a problem that you won't be able to solve on your own, and this is especially troublesome for you because I believe you said you have no dealer...

I never used the correct charger,i was using normal chargers and I’m going to try a lithium lifepo4 battery charger once delivered after two days

 

[Deleted member 1697]

the "truck" version

 

[NC_Taycan]

I guess the dc dc converter is working because every time I give a jump start with an external battery I can drive the car without any problem except that red message saying electrical system fault due to the weak 12v battery..
Do you think that if the 12v battery is totally drained needs special charger to wake up again and accept charging?

I think the 12V message is a warning that your battery had a problem. If you jump the car, drive it, shut it off and lock it for 15 minutes then come back, that message should be gone. If you do that but your battery is now dead after 15 minutes then you could have a bad 12V battery. In either case though, this is a better situation than having a bad DC-DC converter when you don't have a dealer close by. I don't know how to tell you to diagnose a bad 12V battery though in this car.

 

[chrisk]

Looking at the info in the rightmost column of the instrument clust I see that the small battery voltage is about 12.9v when I turn on the car. Then within a few seconds after turning the car on it gets to 13.4V.
12.9v is an indication that the battery is not bad, and the increase to 13.4 is an indication that it is properly charged by the big battery when I drive.

What are these values in your case? If the voltage does not increase after you turn on the car, then I guess there is a problem with the converter. If the voltage increases but the initial value is low, then I assume the battery is bad and it does not hold any charge.

I hope that might help you diagnose a bit.

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