Tony, I am sure someone will not like this suggestion:
With the car idling, pull the positive battery connection. If the car still runs and you can read a 12 or more volts output from the electrical system, there is a good chance the system is working.
A normal GM system with a single "self excite" alternator will allow a battery to run it's life of 5 or more years. We have gotten up to 7 years on batteries here in the winter wonder land.
1 year doesn't sound right. Rick has a list there that may help you get to the bottom of your problem.
Hope this helps. Like I said, someone will most likely say something about pulling the positive connection to the battery, but it works.
