Issue with 12v battery

[snstevens]

The recommendation has been in place since 2020. Below is the official Porsche documentation.

As for a good trickle charger look for a CTEK Lithium Charger. As long as the trickle charger is designed for Lithium charger, as the charging parameters are different from normal lead acid batteries

The document you attached is numbered 2003.1, and the original 2003 version is different.

Since your version is later, I find this paragraph interesting --

Note that they don't recommend a "maintainer" for the battery, but rather recommend the car be connected to an EVSE on one of the charge ports. So the attachment doesn't specifically mention a trickle charger, but the user's guide does. Weird.

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[Tooney]

Man, I thought we had resolved this 3 years ago when Porsche said you should simply leave your Taycan plugged in to a charger when out of town for a while. My understanding was that the HV battery would periodically be used to keep the 12V Lithium-Ion batter at full charge.

When and why did the recommendation to use a trickle charger come about? Anyone know?

The Porsche guy who writes the manuals read the advice from owners on this forum and updated all the online Taycan manuals.

Too bad you and the rest of us existing owners aren't re-reading the online manual versions regularly to find out about the changes.

After all, doesn't it make sense that Taycans with 80+ kw HV batteries should need trickle chargers to keep the 12-volt battery from discharging in the winter, in addition to keeping the HV system plugged in to a Level 2 charger?

 

[Scandinavian]

I am not aware if there are any further updates to the ATI. If you look at the history it was issued and then withdrawn and the reissued. There was also a detailed description of the initial charging cycles in a manual for Audi, that highlighted the sequence of 8 cycles while the car stayed unused. I have no information about any new SW release if that 8 cycle limitation was revised later??

If you refer to this
Taycan vehicles cannot be charged using the Charge-o-mat Pro maintainer available from Porsche Tequipment.

that just emphasises the fact that the normal 12 volt battery maintainer for lead acid batteries will not work with the Taycan. It is designed for normal lead acid batteries! There are different charging parameters for Lithium batteries.

 

[Tooney]

RTFM, @Scandinavian, RTFM.

 

[Scandinavian]

RTFM, @Scandinavian, RTFM.

I think that old advice was for the older version of the Charge-o-mat unit. The new one has specific settings for both types of batteries, lead acid and Lithium. That unit was not available in 2020? The new one is a Charge-o-mat Pro!

 

[Tooney]

The last TSBs/ATIs that I can find at NHTSA about storing Taycans (dated March 2022) do not mention/advise using a trickle charger on the 12-volt battery. Dealers are advised to charge the 12-v battery every 8 weeks using a suitable Li charger. Nothing about "maintaining" with a trickle charger.

The current online owner manual version conflicts with TSB. Such is life.

 

[Mikegrr]

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.

 

[snstevens]

I think that old advice was for the older version of the Charge-o-mat unit. The new one has specific settings for both types of batteries, lead acid and Lithium. That unit was not available in 2020? The new one is a Charge-o-mat Pro!

Let's put aside for a second the disconnect between the Owner's Manual and the Porsche Technical Bulletin #2003.1, and just assume that a trickle charge is a good thing so just do it (might or might not really be true).

What I find interesting about the Charge-o-Mat Pro is that it appears to connect to the battery via a 12V socket on the inside of the car. Since it says in the Owner's Manual that the 12-Volt sockets (and USB -C ports) are always active even if the Vehicle is switched off, I get the impression that you simply plug the Charge-o-Mat Pro into the socket, and connect it to a wall plug (running an extension cord out the door or window of course.

Am I understanding this right? If so, seems a lot more convenient than opening the Frunk, removing the plastic, and connecting two alligator clips to the battery and post.

 

[tophamn]

Let's put aside for a second the disconnect between the Owner's Manual and the Porsche Technical Bulletin #2003.1 for a second, and just assume that a trickle charge is a good thing so just do it (might or might not really be true).

What I find interesting about the Charge-o-Mat Pro is that it appears to connect to the battery via a 12V socket on the inside of the car. Since it says in the Owner's Manual that the 12-Volt sockets (and USB -C ports) are always active even if the Vehicle is switched off, I get the impression that you simply plug the Charge-o-Mat Pro into the socket, and connect it to a wall plug (running an extension cord out the door or window of course.

Am I understanding this right? If so, seems a lot more convenient than opening the Frunk, removing the plastic, and connecting two alligator clips to the batter and post.

Reading the instruction manual for the charge-o-mat Pro (here: https://assets-prod.porsche.com/ven...517682857341eb23fd3f2219cf299c7c_document.pdf) it appears you're correct - though note this comment:

Vehicle socket has been deactivated (max 30 minutes). The vehicle's 12V sockets are deactivated if no charge is applied for 30 minutes to protect the vehicle battery. • Turn vehicle ignition on and off once before charging if the ignition has been turned off for more than 30 minutes. • Switch on the vehicle ignition once after the charger has been disconnected for more than 30 minutes, e.g. through a power cut.​

 

[Tooney]

RE: using Porsche charge o mat Pro for Taycan 12v battery.
TSB dated May, 2024 for 3 Porsche models:
https://static.nhtsa.gov/odi/tsbs/2024/MC-11001065-0001.pdf

 

[snstevens]

RE: using Porsche charge o mat Pro for Taycan 12v battery.
TSB dated May, 2024 for 3 Porsche models:
https://static.nhtsa.gov/odi/tsbs/2024/MC-11001065-0001.pdf

I think that last remark – “cannot be charged” - refers to the inability of the Charge-o-mat Pro to charge a dead battery as opposed to using it for trickle charge.

Do you agree?

 

[tophamn]

I think that last remark – “cannot be charged” - refers to the inability of the Charge-o-mat Pro to charge a dead battery as opposed to using it for trickle charge.

Do you agree?

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.

 

[M3Taycan]

I think that last remark – “cannot be charged” - refers to the inability of the Charge-o-mat Pro to charge a dead battery as opposed to using it for trickle charge.

Do you agree?

No. My interpretation is the "information is not relevant for the Taycan". It should have been reworded to say the following is my suggestion: The Charge-o-mat Pro can not be used to charge the Taycan PB/PB+ battery.

 

[snstevens]

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.

 

[anonymouse]

This avoids the need to manually reset the CTEK unit if there is a power glitch.

My Ctek doesn’t need any resetting - just plug in and go. No need for a UPS

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