[kenac]

Yeah, you pop the hood and it's on the left side towards the passenger compartment. There's a little black compartment that you can open and it'll contain the positive (+) terminal. The negative (-) terminal is just outside and down to the right of that compartment. They're silver colored and hard to miss with the big +/- symbols stamped into the top of each.

I don't have my car right now, otherwise, I'd post a picture. I'll do so when I get it back.

Yeah, you pop the hood and it's on the left side towards the passenger compartment. There's a little black compartment that you can open and it'll contain the positive (+) terminal. The negative (-) terminal is just outside and down to the right of that compartment. They're silver colored and hard to miss with the big +/- symbols stamped into the top of each.

I don't have my car right now, otherwise, I'd post a picture. I'll do so when I get it back.

Ok, thanks, I'll look

 

[JNealCox]

Yeah, this happened to me yesterday. Woke up, car was dead. 80% charge in the main battery, but the 12V battery was only pushing 5V, so the main computer couldn't even wake up to unlock the car. Had to "jump" it with an external 12V power source. Funny thing was that this is the first time it has happened to me and it was in front of this guy's house: Car died over night…. Apparently Taycans have the exact same crappy problem. Yay software. Apparently Teslas also suffer from this sometimes as well. The e-tron is apparently the easiest to recover because popping the hood is mechanical. I now have one of these in my frunk: https://www.amazon.com/NOCO-GB70-Ul...l+12v+car+battery+pack&qid=1616514189&sr=8-19. It seems that you only need to supply external 12V power long enough to boot the main computer and turn on the car, which immediately discovers that its own 12V battery is depleted and starts charging it from the main battery. I really do NOT want to get good at fixing this problem.

What causes this kind of drain on the 12V battery?

 

[kenac]

Ok, thanks, I'll look

Well, I got the eTron to "start". I hooked up my Charger to the 12v terminals overnight and this morning it "started". I will still take it to the dealer tomorrow. Thanks nbrosnahan.
It could be an architectural design problem or a battery control problem???

Warning: this is an extremely high current area so beware -- at your own risk.

 

[nbrosnahan]

Warning! This is a "die here by touching the wrong thing" area. Please be careful.
Here's a picture:

 

[nbrosnahan]

I got my car back from the Audi dealership. They did some software updates, but I am not convinced they have fixed the problem yet. Time will tell. The battery draw seems to happen when the car is plugged in for charge, is on a delay timer for future charging, and you do something that "upsets" the software on the main computer (possibly change the target SoC or something). My buddy Dave's theory (he's a Taycan owner with virtually the same problem), is that there's some software spin loop that is triggered (intermittently) and when it's in that state, the 12V battery is being drawn down by the main computer, which wakes up and goes to sleep continuously until the 12V battery is dead. Until Audi can isolate the problem, it's likely to happen "sometimes" and there's nothing the dealership can really do other than pull logs and send them to Audi/Porsche for their firmware engineers to ponder over.

 

[kenac]

Well, I got the eTron to "start". I hooked up my Charger to the 12v terminals overnight and this morning it "started". I will still take it to the dealer tomorrow. Thanks nbrosnahan.
It could be an architectural design problem or a battery control problem???
View attachment 1473
Warning: this is an extremely high current area so beware -- at your own risk.

The dealer found a faulty battery under load and replaced it. For the past few days it's been working well again. Hopefully it will stay that way until a fix becomes available.

 

[nbrosnahan]

It happened again. Back in the shop again. I have a workaround, but for a car that cost $80K, I am not happy.

 

[Jonibegood]

It happened again. Back in the shop again. I have a workaround, but for a car that cost $80K, I am not happy.

Not sure how things work in US but over here in UK most complaints are treated with suspicion by the dealer so unless they can recreate it, it didn't happen!! Since I've had this issue my charger (PodPoint) have released an update so the timing is now done by the charger. So, effectively I am plugging a dead charger into the car and it activates at 1230am when my lower tariff starts. I've been doing this a few weeks and the discharge issue hasn't happened.

 

[nbrosnahan]

Not sure how things work in US but over here in UK most complaints are treated with suspicion by the dealer so unless they can recreate it, it didn't happen!! Since I've had this issue my charger (PodPoint) have released an update so the timing is now done by the charger. So, effectively I am plugging a dead charger into the car and it activates at 1230am when my lower tariff starts. I've been doing this a few weeks and the discharge issue hasn't happened.

So, effectively, you have the car charging immediately, but move the scheduling to the external charging station? That aligns with other reports, which is that the car gets confused when starting a charging session because of some bug and then just loops forever draining the 12V.

 

[nrosoff]

This may answer some of the question regarding this issue. It also raises a few.

 

[JNealCox]

Interesting. So leaving the car connected to mobile charger will not let the car fully shutdown? I was also told by my dealer that, even if NOT plugged in, the car will not fully shut down unless the doors are locked.

 

[nrosoff]

Interesting. So leaving the car connected to mobile charger will not let the car fully shutdown? I was also told by my dealer that, even if NOT plugged in, the car will not fully shut down unless the doors are locked.

Not only the mobile charger. I asked the tech would the same thing happen if I used a charger that shut off the current after a specified period of time. He was not sure but suspects because either the charge door is open or the latch dectects the cord is pluged in, it would do the same thing.

 

[Lucken]

Interesting. So leaving the car connected to mobile charger will not let the car fully shutdown? I was also told by my dealer that, even if NOT plugged in, the car will not fully shut down unless the doors are locked.

That's interesting. Since I park in my own garage, I don't typically lock the doors. So if this is true (and it should have been in the owner's manual), it may be good practice to lock the doors.

 

[JNealCox]

That's interesting. Since I park in my own garage, I don't typically lock the doors. So if this is true (and it should have been in the owner's manual), it may be good practice to lock the doors.

Especially if you are not going to be driving the car for a few days.

 

[azlkk]

Curious, I left the car plugged into the Chargepoint charger for 6 weeks in the garage unlocked and had no problems when I returned. Main battery had lost 1% charge in a month before the car apparently shutdown communicating with the app.

 

[Jonibegood]

In my experience the car’s 12v battery only discharges whilst it is connected to the charger but charging is being delayed by the car’s schedule/timer function. So, my off peak tariff starts at 12.30am and that is the schedule I‘ve set up in the car. If I plug the car in at 4pm, in the time it’s waiting (8.5 hrs) it can flatten the car’s 12v battery. So, I used to plug it in before going to bed at say 10.30pm and it was fine. Now, I’ve turned the car’s schedule off as the home charger has a timer function. I can now connect the car to the charger earlier in the day and the issue hasn’t returned. I think this is just Audi being very slow to fix what is probably quite a simple software issue.

 

[nrosoff]

Curious, I left the car plugged into the Chargepoint charger for 6 weeks in the garage unlocked and had no problems when I returned. Main battery had lost 1% charge in a month before the car apparently shutdown communicating with the app.

Now this is interesting. Did you set the Charge Point to charge during certain times of the day? When "I asked the tech would the same thing happen if I used a charger that shut off the current after a specified period of time. He was not sure but suspects because either the charge door is open or the latch dectects the cord is pluged in, it would do the same thing." was his speculation. What we are calling chargers are nothing more than high current contactors with some fancy electronics to control it (ie WIFI, Time of day charging, etc.). If the contactor is open (no current) would I have had the same problem. I speculate there is communication between the Audi interface that cause the electronics to wake up and drain the battery.

 

[Lucken]

In my experience the car’s 12v battery only discharges whilst it is connected to the charger but charging is being delayed by the car’s schedule/timer function. So, my off peak tariff starts at 12.30am and that is the schedule I‘ve set up in the car. If I plug the car in at 4pm, in the time it’s waiting (8.5 hrs) it can flatten the car’s 12v battery. So, I used to plug it in before going to bed at say 10.30pm and it was fine. Now, I’ve turned the car’s schedule off as the home charger has a timer function. I can now connect the car to the charger earlier in the day and the issue hasn’t returned. I think this is just Audi being very slow to fix what is probably quite a simple software issue.

Yes, that's exactly how I have mine setup via my ChargePoint Home Flex charger. It seems using these chargers and their timer functions obviates many of the issues that are encountered using the car's onboard setup.

 

[JNealCox]

Yes, that's exactly how I have mine setup via my ChargePoint Home Flex charger. It seems using these chargers and their timer functions obviates many of the issues that are encountered using the car's onboard setup.

I could see where using the onboard timer/etc would require the car to stay awake to some extent. However, I use the timer pretty often: plug it in about 5pm timer set to complete by 830AM, but I have not had any issues. Still, I have not actually checked the 12V battery.

 

[nickwild]

This happened to me last night - thanks all for documenting this. I had not set delayed timing (either in car or on my podpoint), but I had left my charging cable in for 2 days. The alarm went off and then the rear lights flashed and on the display there was a battery service warning before it went completely dead.

This bug and the generally really poor software (my MMI keeps crashing and has to be reset, issues with the door locks and seats not retaining their memory) has made this a very poor experience of Audi ownership. The software feels barely out of beta never mind released for production.