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Audi A3: How to Replace Battery

Over time, your battery is going to wear down until one of the cells goes bad. At that point it's time for a new battery. This article will show you how to change it.

By Jared Hammond - March 23, 2016

This article applies to the Audi A3 (1996-2008).

So you get out to your Audi A3 one morning and you find that it won't start. The first thing you try is charging the battery. The car starts and you're on your merry way, except, when you go back to your car later, it still won't start. You probably have a bad battery and need to replace it. Don't worry about it. Changing a battery is a breeze.

Audi A3: How to Replace Battery

Materials Needed

  • Replacement battery
  • 10mm wrench
  • Ratchet with 30mm socket and extension

Make sure that the replacement battery you purchase will fit in your car's battery tray. Some batteries, such as the Optima brand batteries, are larger and harder to make fit.

Step 1 – Disconnect the battery cables

Pull the hood release lever by your driver's side kick panel. Pop open the hood and locate the battery box. On most Audi models, this is in the center of the cowling. Unclip the lid to the box and you should see the battery with two cables going to it. There should be labels for the positive and negative terminals. Use your wrench to loosen the battery cable clamps on the negative terminal. Slide the cable off the terminal and pull it away so it won't accidentally touch the terminal. Now repeat this for the positive cable on the positive terminal.

AUDI A3 A4 B7 B8 BATTERY REPLACEMENT REMOVE HOW TO CHANGE
Figure 1. Remember to always remove the positive cable first.

Step 2 – Remove the old battery

You'll find that your battery is clamped down to the battery tray by a bracket. There should be a bolt just outside the box that holds down this bracket. Remove the bolt. Now carefully pull the battery off the tray and set it aside somewhere safe.

AUDI A3 A4 B7 B8 BATTERY REPLACEMENT REMOVE HOW TO CHANGE
Figure 2. Loosen the bracket bolt.

Step 3 – Install new battery

Position your new battery on the tray in the same way the old battery was positioned. Make sure that the terminals are facing the correct battery cables. You absolutely do not want to get those mixed up. Return the bracket and tighten down the bolt to secure the new battery to the tray. If you're looking for extra corrosion protection, spray some terminal protector on the terminals of your new battery. Then attach the positive cable and negative cable just like how you removed them. Now try starting the car. Hopefully your new battery shows that it's charging on the voltmeter.

If you find that this doesn't solve your starting issues, you may want to either try returning the new battery, or checking the alternator. It is possible that the alternator is not charging the battery enough.

AUDI A3 A4 B7 B8 BATTERY REPLACEMENT REMOVE HOW TO CHANGE
Figure 3. Install new battery.

Pro Tip

Batteries contain hazardous materials, so make sure to turn in your old battery to a dealership or auto parts store to get a recycled.

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