I have a 2001 Dakota 3.9L and I can't keep the battery charged. I had the altenator checked and it is good. I put a new bettery in it 1 month ago. Yesterday, I jumped the truck and went to my son's Tee ball game which is about 20 minutes of city driving.About an hour later when I left the game, I had to jump it again. When I got home, I killed it and started it 3 times, let it sit for an hour and started it again. This morning I went to start it and it was dead. I am thinking of driving the truck for a while tonight and disconnecting the battery and then trying again in the morning. Any ideas?