Replacing OEM battery S4 B8

[Strong Man]

Did someone connect external 12v charger during the replacement process ?! so the car won't lose 12 volts and don't go to the full system reset.

[Bshiau]

Did someone connect external 12v charger during the replacement process ?! so the car won't lose 12 volts and don't go to the full system reset.

I hooked up a battery tender to the positive and negative posts under the hood. Not sure if I really needed to, but others have suggested it, and I already have one for my bike.

[jsh139]

Did someone connect external 12v charger during the replacement process ?! so the car won't lose 12 volts and don't go to the full system reset.

The car won't go into a full reset if it loses power. The only thing you'll lose is the clock and the Trip Computer 2 values.

[HobbesA5]

Just bumping this helpful thread to add a data point.

I just replaced the battery in my 2009 A5 after getting 11 years from the original battery. I went with the linked battery in this thread from Advance Auto. However, the batteries there are now labeled as DieHard instead of AutoCraft, so I assume they bought the brand name from Sears.

I got the DieHard Gold H9 (non-AGM) and it was a perfect match for my original battery. It had the same AH rating and was even manufactured by the same OEM in Germany (Varta). It also had a BEM code sticker on it so that I could properly code it with my VAG-COM.

I keep my cars a long time, but after getting 11 years from the original battery, I assume this one will last until I replace the car.