alternator or voltage regulator on 2005 Saturn Relay

my battery went dead ,changed my info center says charging system failure but it comes on and off. also battery volts goes up and down 11.2 -15.0.what could be the problem?

Asked by for the 2005 Saturn Relay
You need to inspect the data stream of your charging system. The Voltage regulator is now part of the Engine Computer, so first check your Alternator. It could be a bad rectifier, brushes, connections etc.
Unchanging this same issue I've changed my battery with a new one and replaced the alternator what could be the problem
1 more answer
I had the same problem, charger system failure. Check the fusible link wire between the starter and the alternator.