i got an 87 p/u, i drove it yesterday with no trouble starting or anything, this morning i went out to warm it up and battery was super weak, i had to jump it, after that i went to my buddys house for like 4 hours, went to start it, it started but bat was def weak...could it be the alternater or just the severe coldness up here in CT?

 

how old is the battery?
also i dont know on the pickups but on my 4runner u have to push a button then turn the key to take it out or else the clock and things are still on, that killed my battery

 

couple months on battery, and key wasnt in it