Likely the battery lifespan is over.....i changed my MF battery at AS in Apr 2010 and dead in Jul 2011....prior to that was using AAS Amaron MF battery for 3.5yrs.....
for my car, the symptoms were weak cranking, a/c AUTO button cannot activate immediately when engine start....
changed back to AAS Amaron MF battery in Jul 2011 for $138 with gst with their roadside assistance....