How can I troubleshoot battery drainage in my Audi A2?

I've noticed that my Audi A2's battery always drains quickly, even when it's not in use. What could be causing this and how can I fix it?

It's important to first check for any electrical components that may be left on, such as lights or chargers. If everything seems to be turned off, it could be an issue with the battery itself.

Another possible cause of battery drainage could be an old or faulty alternator. It's worth getting this checked by a professional to ensure it's charging your battery properly.