GMC Repair: pontiac g-6 battery issue, wiggle test, loop mode

Question
hi there.  i have an 07 g6 with the standard v-6.  about a week ago it became difficult to cold start.  it didn't have and issue turning over, but rather not enough juice to get the starter starting.  after it started, it runs and drives fine.  now it finally won't start, all of the electrical accessories work fine, but it won't get cranking over, it just makes the ever famous clicking noise.  the maintence has been kept up on it just fine, i cant see any corrosion anywhere and all the connections seem tight,(i haven't checked  the starter 100% yet due to the fact i can't get under the car, and haven't had time to take off the air duct to check it out, i did do the wiggle test though and it seemed fine.)  does it sound like the battery needs to be replaced, or something else maybe?  everything on the car works fine, it just wont crank over.  I thought i'd ask the expert before bringing the battery down to a parts store and have them sell me a shady battery.  any help is greatly appreciated, thank you.  joshua plowman.

Answer
it could be a battery we have seen some with issues, i guess my only question is do you have onstar or xm radio?  we have seen some of theses cars get stuck in a loop mode where the modules do not power down and end up draining the battery. IF your local parts store has the capability to test the battery in question that would be a good idea, it would rule out a starter issue