I kinda knew that my battery needs to be changed. But it never stood me up. I went for state inspection, and when I came back to pick up the car, it wont start, the lights in the guages were on, but it would just make a ticking sound and wont even turn. I am gonna replace the battery tomorrow but the guy said that the alternator might need to be changed as well. $300 for alternator. Is this right? My battery light never came on while driving or idling. How do you know if the alternator needs to be changed or not. I dont want him doing it unless it's required. What are the symptoms of a bad alternator and does the alternator actually is around 300?