Bill, thanks for the answer. When I've changed the battery, it was in a Volvo certified garage. They change it, so I presumed that it was properly done. I am not a car mecanic. How can I see in my garage if the steps have been follow like you described.

Regards

A few times now when I am driving my V50 2005, all electronic component shuts down. I have a brand new battery. This happens when I open the drivers window. Can somebody tell me the problem.