Installing an Optima Red Top R34 Battery into a 1998 A4 2.8 Quattro.
Installing a Optima Red Top battery into a A4 has been done by many folks but this method allows use of the existing parts without having to use a tie down strap as shown in this photo I borrowed from other tech articles.
Before you get started – locate your security code for your radio – If you do not have the code – get one of those 9 volt battery back-ups that plug into the cigarette lighter that will maintain power to the radio. Here is a picture of one.
Remove the old battery – Using a 11mm open or boxed end wrench loosen the clamps on the battery terminal. Loosen the ground terminal clamp first and slip it off the terminal – this reduces the chance of shorting the wrench on the positive terminal. Next using a 13mm socket wrench with a extension – remove the battery hold down bolt. Then remove the battery.
Using a 13 mm socket – remove the bolt on bottom of the battery support bracket. Next using a box end wrench remove the two 13mm nuts at the top of the bracket and then remove the bracket. You can see the battery hold down bolt placed back into the first hole on the battery support bracket in the photo below.
Using vice grips – bend the positive side of the battery bracket flat as shown here.
Use a vice to flatten the bracket more. Then put the battery on the bracket and slide the battery over till you can put the battery clamp bolt in the second hole (OEM battery bolt normally goes in the first hole.)
Next mark where the battery is located on the flattened section on the bracket. Take the bracket to a vice and bend it at that location.
Test the battery fit on the bracket with the support bolt/clamp – and then paint the bracket with Rust-Oleum paint.
Install the bracket back into the car. Install the battery and then put the support bolt/clamp on using antisieze compound. You can see here that the Optima is smaller than the OEM battery and is using the second hole of the support bracket.
Install the Positive clamp to the battery and tighten – then repeat with the negative terminal. The final results should look like this.
Enter the security code into your car radio to activate it. Remember that your mileage information will be gone from the central display – except for the actual car odometer.