Yeah, that would be my first guess too. Hold old is your current battery?
At least you weren't stranded somewhere and not able to start the car.
I used to used Diehard batteries until I learned that they really lived up to their name. They died HARD, rarely giving you any warning until they just fell over dead. At least in my experience.
Lately been using batteries from Advance Auto. They seem to be as good as anything else I have tried.