Sponsored

Issue with 12v battery

snstevens

Well-Known Member
First Name
Sam
Joined
Jul 10, 2020
Threads
31
Messages
1,334
Reaction score
1,739
Location
Kirkland, WA United States
Vehicles
Taycan 4S
Country flag
No use on a Taycan. You can’t charge via the plug as it is cut off when the car sleeps. You need a direct (preferably fused) connection to the battery.
Actually, the owners manual says that the power stays on as long as there is something connected that uses it.
 

anonymouse

Well-Known Member
Joined
May 12, 2023
Threads
44
Messages
756
Reaction score
899
Location
Oxfordshire UK
Vehicles
Taycan Turbo Sport Turismo J1.2
Country flag
The reset has to happen if your power goes out while you’re using it. The CTEK does not restart on its own after a power outage.
Both of mine seem to do so. I regularly unplug them when I need the socket for something else.
 


snstevens

Well-Known Member
First Name
Sam
Joined
Jul 10, 2020
Threads
31
Messages
1,334
Reaction score
1,739
Location
Kirkland, WA United States
Vehicles
Taycan 4S
Country flag
Well good luck and let us know if the many posts about this on the forum are wrong.
Man, don’t get me wrong - I hope you’re correct!

Who knows for sure if the manual I was reading on line was current or not. I plan to test it and see what is what…
 

f1eng

Well-Known Member
First Name
Frank
Joined
Aug 19, 2021
Threads
48
Messages
4,765
Reaction score
8,335
Location
Oxfordshire, UK
Vehicles
Taycan CT4S, Ferrari 355, Merc 500E, Prius PHV
Country flag
The reset has to happen if your power goes out while you’re using it. The CTEK does not restart on its own after a power outage.
That is odd. I haven't needed the reset button on mine ever. I just connect it to the battery using the croc clips and plug it in.
If I understand the manual correctly the reset button on the CTEK needs to be used if the 12V battery is so flat it has gone into self protect mode. Pressed for > 10 seconds resets the self protect in the battery itself.
 

snstevens

Well-Known Member
First Name
Sam
Joined
Jul 10, 2020
Threads
31
Messages
1,334
Reaction score
1,739
Location
Kirkland, WA United States
Vehicles
Taycan 4S
Country flag
That is odd. I haven't needed the reset button on mine ever. I just connect it to the battery using the croc clips and plug it in.
If I understand the manual correctly the reset button on the CTEK needs to be used if the 12V battery is so flat it has gone into self protect mode. Pressed for > 10 seconds resets the self protect in the battery itself.
I believe you are right. Here is what I was able to gather online.


Yes, the CTEK 56-926 Lithium US charger will work after a power outage. This model is designed to automatically reset and resume charging when power is restored.

The charger features a fully automatic 8-step charging cycle, which includes a reset function. In case the charger doesn't automatically restart, it has a manual reset button that can be used to restart the charging process.

It's worth noting that some older CTEK models did not automatically reset after power failures, but the newer units, including the 56-926 Lithium US, do have this capability. This feature ensures that your LiFePO4 battery continues to receive proper care even after unexpected power interruptions.
To maximize the effectiveness of the charger after a power outage:

  1. Check the charger's status indicators when power is restored.
  2. If needed, press the reset button to manually restart the charging process.
  3. Verify that the battery is properly connected and within the charger's supported capacity range (5Ah to 60Ah for charging, up to 120Ah for maintenance)
By following these steps, you can ensure that your CTEK 56-926 Lithium US charger continues to provide optimal care for your LiFePO4 battery, even after unexpected power interruptions.
 


f1eng

Well-Known Member
First Name
Frank
Joined
Aug 19, 2021
Threads
48
Messages
4,765
Reaction score
8,335
Location
Oxfordshire, UK
Vehicles
Taycan CT4S, Ferrari 355, Merc 500E, Prius PHV
Country flag
you can ensure that your CTEK 56-926 Lithium US
Mine is a CTEK Lithium XS UK since I am in England. It may be the same but the instruction book doesn't have that text.

It does say it may give an error if charging is interrupted during accept or analyse phases and need a reset. Given the accept phase is 30 secs maximum and analyse up to 3 minutes it would be unlucky given the whole procedure can be up to 42 hours for a reset to be needed if the charge is interrupted ;)
 

Scandinavian

Well-Known Member
First Name
Peter
Joined
Nov 3, 2019
Threads
52
Messages
3,904
Reaction score
3,549
Location
France
Vehicles
Taycan T, Aston Martin DB9, Porsche 996 C4 Cab, i4
Country flag
I have used the same CTEK Lithium XS charger since 2020 and been very happy with it. My unit will start automatically when plugged in and I have never had a problem with any power outage. It has come back automatically. We had some severe thunderstorms and the power supply suffered sevaerl times one year, but still no problem for the unit.

For me the RESET button has been used once when the 12 volt batter was depleted and the safety relay had kicked in. As per instruction all came back and the relay reset by pressing the RESET for 10 seconds or so.
Porsche Taycan Issue with 12v battery IMG_2451


I have been very happy with this unit for 5 years and used it on the Taycan and a few other marine batteries.
 

Spyerx

Well-Known Member
Joined
Jan 8, 2022
Threads
4
Messages
121
Reaction score
95
Location
SoCal
Vehicles
CT4
Country flag
I think it probably means it won't charge the high-voltage drive battery, though I agree it's vague.

That said looking at the Tequipment website the Charge-o-mat Pro is not listed as compatible with any Taycan model.

I think this is what is meant. Its vague.


Decided to order the CTEK 56-926 LITHIUM US | Fully Automatic Lithium Ion Phosphate LiFePO4 Battery Charger | 5.0Ah - 60Ah | Maintenance Charging up to 120Ah from Amazon. This is essentially the same unit as the Porsche Charge-o-mat Pro, but cheaper (the Porsche branded unit is $204 on Amazon).

Also ordering the 8 ft CTEK (56-304) Comfort Connect Extension Cable, and the CTEK Comfort Connect Cig Plug. Total $164 for the bundle including WA sales tax.

As it happens, I have a small UPS on the wall in front of the Taycan which keeps my Optical Network Terminal (FiOS Gateway) and my main Internet router running during a power outage, and the backup generator kicks on in 10 seconds. My intention is to plug the CTEK into that UPS and mount it to the wall nearby. This avoids the need to manually reset the CTEK unit if there is a power glitch.
As stated, it's not needed, the CTEK lithium will remember the charge state and just start the cycle over. Ive had one of these for another car with LI for several years and the unit works great.

I have 6 different CTEK and they all remember the charge state / setting.

Also, the newest porsche charger is a rebranded CTEK, but, you can't buy this model of CTEK last I saw, that allows both Lead Acid AND Lithium charging from a single unit. This is a nice feature of the Porsche branded CTEK.

Actually, the owners manual says that the power stays on as long as there is something connected that uses it.
Yeah that is supposedly how it works, but I've struggled with newer porsches and use a direct to battery connection (pigtail although the clamps work too).

What you are supposed to do is: turn car off, plug in the cigarette lighter plug, ensure charger has started, then lock the car. If the car senses it is charging it doesn't deactivate the 12v plug when it sleeps. However, I saw this functioned inconsistently on my other Porsches. Could be user error who knows.
 
OP
OP

Bossie

Member
First Name
Luc
Joined
May 7, 2024
Threads
1
Messages
6
Reaction score
2
Location
Belgium
Vehicles
Taycan GTS ST 2023, Carrera 4 GTS Cabrio 2017,
Country flag
Apparently the problem is not solved with a trickle charger. It is driven regularly. The car is with the OPC since 3 weeks and they completely rely on the Porsche engineers' help in Zuffenhausen. It seems to be a complex software issue that results in unnecessary draining of the 12V battery. No idea yet when the car will be ready again. Cross fingers.... .
 

bob66hall

Active Member
First Name
Bob H
Joined
Jan 2, 2023
Threads
0
Messages
30
Reaction score
27
Location
Reno/Tahoe, Nevada
Vehicles
Taycan 4S 2021; 911S Cab 2012; Cayenne Turbo 2014; BMW iX 2023
Country flag
Yes, have read the threads, and the read the manual. Just picked up my 2021 4S from the dealership (Reno), after a multiple-recall service. Asked the service manager to clarify best way to maintain both batteries during one to three month winter storage, inside my home garage. Their answer: Store with wall charger attached, plus trickle charger attached directly to the 12v battery (using gator clips, NOT cigar lighter port). Suggest you all just take this as "one more" view, yet from [what should be] a decent source (Porsche dealer service manager). Ignore the 110v question, and the "Tesla" note, as those were unrelated questions. And do pay attention to charging level pre-sets, use of timers, and so forth....all well covered in earlier thread comments.

In conclusion, having been at this for three years of 4S ownership, and three winters of home garage storage, this is my plan:
1) Attach wall charger.
2) Set timer to charge every Monday, to a 60% charge level.
3) Attach trickle charger, using gator clips, directly to the 12v battery located in the frunk.
4) Follow other owner's manual instructions for tire over-inflation, etc.
5) Continue paying attention to the great community we have here on Taycan Forum, and doing my best to contribute!

Porsche Taycan Issue with 12v battery 1741988080358-nl
 
OP
OP

Bossie

Member
First Name
Luc
Joined
May 7, 2024
Threads
1
Messages
6
Reaction score
2
Location
Belgium
Vehicles
Taycan GTS ST 2023, Carrera 4 GTS Cabrio 2017,
Country flag
Hereby an update on this thread that I started about a month ago. The car is finally repaired. Several modules were replaced and some of the software re-installed. Porsche Germany was directly involved.
Apparently, there was a current loss on the 12v battery of 2.95 amps. That is much too high. The german porsche engineer now says that the loss is "much less". It would now be 0.95 amps which is 'normal'. Can anyone confirm that this is ok? Or do I still have to worry that the battery can drain. I drive this car almost daily.
 

gareth lloyd

Member
First Name
Gareth
Joined
Nov 25, 2022
Threads
1
Messages
7
Reaction score
0
Location
UK
Vehicles
Mini Cooper SE, Porsche Taycan ST 4S
Country flag
If you turn on the car , does it charge the battery? My car is in storage, if I have someone start the car. How long would it have to run.
Hi, I just wondered wether you got a reply to this question...I too am interested in whether switching car on actually triggers 12v charging
Sponsored

 
 








Top