Makes a woo woo sound when idling after jumping it to start

What is your question?

The wipers stopped working properly, the alarm kept going off and then the battery is now dead. It will start after it's jumped but makes a woo woo sound when idling. Won't start again without a jump. What is making that sound?

What makes this problem better or worse?

Mothing

How long has your 2001 BMW X5 had this problem?

A few weeks