1guitar

I have an A8L, 2016. My year A8 and I assume most of the other model years of this same car (and maybe most Audis) have one very annoying feature, when you shut down the car all the 12 volt outlets also go down. Does anyone know a simple way of taking the 12 volt outlet behind the front seat arm rest in the center rear cigarette lighter so that it will stay live and not shut down when you turn your car off. The reason I ask is that I read a post about a man that changed out his car battery and lost all of the settings etc. for lack of the ability for one of his 12 volt outlets not having the ability to stay on, which made his $150 car battery turn into a trip to the dealer and pay another $125 to have his car "read" his new battery. One thing I can tell you from personal experience, if you need a question answered regarding your Audi that you paid for with hard earned dollars, Audi has a library of BS that they will tell you so that they avoid educating their owners so that you have to go to an Audi dealer's service dept. to have the repair done, heaven forbid that their customers might know how to do anything on their own and save a few bucks. They make very good cars but in the end the Audi Co. of America, LLC is worse than any car company I have ever dealt with. I called an Audi dealer here in the NYC area to ask a very rudimentary question if you are an Audi mechanic, but I am not, in any event, this ding-a-ling gets on the phone and I quote, "It's company policy that we don't give out that information", you spend one to two years worth of salary for an answer like that.
Which pretty well explains why Audi sells a little less than 5,400 units (model: A8L) a year in the USA, a very poor showing for a pretty great car.
PS - For those of us lucky enough to buy a new Audi, the Owners Manual says that you should re-torque your wheels after the first 100 to 150 miles, further for those that care, the correct torque is: 90 Ft. Pounds torqued in a standard 5 star pattern for the wheels on the A8L.
Enjoy the ride.

MP4.2+6.0

I'm looking for the question in here...??

If it is about changing batteries, since at least my D3 about all you lose even on a full battery disconnect is the date. Time typically sticks. On a D4 those come in w/ GPS anyway. Radio settings, saved whatever should all stick. Thus no need for "back up" power. You are supposed to code the battery to the car so the power management system knows what the battery is and resets to the "new" capacity level instead of what it learned over preceding years. In practice using the older D3 generation metric--especially in recent years with a lot of third or fourth owner DIY'ers--many just install battery and drive. At a technical level, unless battery learns only one direction which is sort of illogical (worse over time, not better), then it should eventually figure out the battery is in better shape anyway.

If it is about retained power of something plugged in, search on that. Would probably need to mod it.

Garycw

My 2011 was disconnected around 30 min and didn't loose anything.
All that coding, errors etc when changing bulbs, batteries is my main gripe about bmw's etc.