I had the alternator and battery in my 1995 854T replaced by my Volvo dealer in October 2007. (They've been great -- maintained the car perfectly since new.) I left the car in my garage for 3 weeks while on vacation and returned ~ Jan 7 to a completely dead battery. Temperature in the garage was 44F. No lights, radio, etc were left on. The service dept at my Volvo dealer says this is not uncommon in cars equipped with anti-theft alarm and anti-theft radio protection, and advised me to disconnect the battery the next time I leave the car for more than 2 weeks.
Does this sound right, or do you suspect an electrical fault?
Java