How do I check if my Audi A2's battery is properly connected?

I recently purchased a used Audi A2 and I suspect that the battery may not be connected correctly. How can I check and make sure it is properly connected?

First, check the battery terminals for any corrosion or loose connections. If everything looks good, use a voltmeter to check the voltage of the battery.

You can also try starting the car and paying attention to how the engine runs. If it seems sluggish or has trouble starting, it could be a sign of a loose battery connection.