2010 Chevrolet Cobalt battery light came back on

The battery light would come on occasionally. We had the battery changed. The light still comes on, what would be the problem?

My guess would be the alternator isn’t putting out enough voltage to charge the battery and keep the car running. Did you just replace the battery initially or did you have the charging system tested?

Had the battery tested and they said a third of the life was gone. Changed the battery and we noticed the light still comes on.

The battery light indicates a fault with the electrical system. I think you need to go to your local independent mechanic and have your electrical system tested.

Any auto parts store will check the charging system for free.

If that all checks OK, I would suspect either a loose wire or the tensioner for the serpentine belt is not holding tension.

Yosemite

Buy a $15 voltmeter to plug into your acc receptacle so you can see what the voltage is doing while you drive.

The voltage from the alternator is regulated by the ECU.

A factory scanner or equivalent is required to determine if the ECU is the problem.

Tester