[TonyS]

I had the same problem with my etron gt 12 volt battery going dead. There is a recall to hopefully fix this problem. Apparently some vehicles that were manufactured within a specific period in 2022 had an issue with the 12 volt battery discharging completely due to a software issue in the 12 volt battery control module. This recall in Canada is under the service action-27k2-. Apparently the update will take about an hour in the shop.
Audi sent a tech to my home because the car couldn’t be extricated from my garage with a tow truck. The mechanic has devised a cleaver solution to open the frunk. He had a small 4x4 inch inflatable cushion, much like a blood pressure cuff, that he inserted between the space between the car frame and the frunk lid. When the cushion was inflated there was enough clearance to be able to remove the bolts from the latch of the lid and open the frunk lid. Done in five minutes. No towing necessary, no impact on the car. Brilliant!

 

[e-quattron]

Welcome to the forum.

Thanks for sharing the tip.

Have this store in the car where is accessible for emergencies. You won't be sorry to have it.

 

[e-quattron]

I hope the dealer will replace the dead 12V battery with the EFB+ battery.

 

[JNealCox]

Welcome to the forum.

Thanks for sharing the tip.

Have this store in the car where is accessible for emergencies. You won't be sorry to have it.
View attachment 8893

For the GT, the problem is getting the frunk open so that you can get to the battery.

 

[ace10]

Installing 12v battery cable

Documenting the install of a cable to access the 12 volt battery from outside the vehicle. There have been many posts about this project scattered around the forum. This will allow you to maintain the 12 volt battery and also give you an access point outside the frunk which WILL NOT OPEN if you...

www.e-tronforum.com

 

[TonyS]

Welcome to the forum. Thanks for sharing the tip. Have this store in the car where is accessible for emergencies. You won't be sorry to have it. View attachment 8893

Thanks for the suggestion but if I am in a situation where I need the charger I won’t be able to get into the frunk to use your boost idea because the release is electrically operated. I would be in the same situation as I was before. Hopefully the battery module software update will keep the 12 volt from going dead ever again.

 

[e-quattron]

You're welcome.

Do the trick that the Audi Tech. to your car, to open the hood.

It won't hurt to have a portable battery booster, and it's a cheap ins. to have.

 

[e-quattron]

Hopefully the battery module software update will keep the 12-volt from going dead ever again.

The problem is that VAG installed SLI -Starting Lighting Ignition - 12V battery in their BEV instead of the EFB - Enhanced Flooded Battery - a fancy name for the deep cycle by the inventor, Exide or AGM - Absorbent Glass Mat - battery. The SLI-type 12V battery is for ICEV and can't take charge and discharge cycles that a deep cycle battery can. That's why an SLI-equipped 12V battery BEV goes flat after being driven for a thousand or more km. But, the EFB or AGM battery can take charge and discharge cycles that a BEV demands.
Tesla also has problems with the 12V deep-cycle batteries and started upgrading its vehicles with 12V Li-Ion batteries.

 

[ace10]

The lead extends out from the frunk. It's an inexpensive insurance policy against being stuck in your situation.

But do as you wish.

 

[Internet Rando]

The problem is that VAG installed SLI -Starting Lighting Ignition - 12V battery

It's a $100k+ high-end performance vehicle. If they can't spring the extra $50 for a LFP based 12V battery, which is a lot lighter, has very slow self-discharge, and can take thousands of cycles, they're just being dumb.
Most LFPs even have a little button where you can make them temporarily turn on again after they auto-shut-off for protection.
I put one into the Leaf when the first battery died, and didn't look back. Lasts forever.

Of course, even with the button, you'd still have the problem of getting the frunk open if it shut off. That's just a catch-22 designed-in deadlock kind of problem.
I like the idea of looking for 12V in the fuse box, though -- I might give that a go, just to find out.

 

[e-quattron]

VAG, being an ICEV Mfr., has many SLI- lead acid batteries on the shelves. The reason why the SLI- lead acid batteries ended up in their BEVs, regardless of the vehicles' prices. The SLI lead acid batteries are being replaced with EFB+ batteries for the BEVs.

 

[Greg E]

Installing 12v battery cable

Documenting the install of a cable to access the 12 volt battery from outside the vehicle. There have been many posts about this project scattered around the forum. This will allow you to maintain the 12 volt battery and also give you an access point outside the frunk which WILL NOT OPEN if you...

www.e-tronforum.com

Thanks for your post on this. I have done exactly the same thing with the battery tender cable and adapter. My dealer actually installed the cable for me when I was there for a software update.
Just confirming, the NoCo charger needs to be set on 12v Lithium, correct?

 

[ace10]

Thanks for your post on this. I have done exactly the same thing with the battery tender cable and adapter. My dealer actually installed the cable for me when I was there for a software update.
Just confirming, the NoCo charger needs to be set on 12v Lithium, correct?

IIRC my 5 Amp NOCO auto selected Lithium when I tested it. I did not have to scroll.
Which is interesting because I often have to manually select AGM when I'm hooking to one of those.

 

[Greg E]

The owners manual said it is a Lithium battery so that is what I'm going with. Do you happen to know, if the 12v battery goes dead, if you can still get into the car (doors will unlock or trunk will open?) I was going to keep the charger in the car or trunk but then realized, if the 12v controls those too, I would be screwed! Crazy to have to worry about this stuff on a 100+K vehicle! Thanks for your thread though, the Battery Tender cable was a great suggestion. I have used that forever on my boat battery in the winter.