2005 Chrysler Town and Country

Electrical problem
2005 Chrysler Town and Country 6 cyl Front Wheel Drive Automatic 42,500 miles

Purchased a used 2005 Chrysler T& C van 6 months ago. Right after buying it I noticed that if I listened to the radio in the auxiliary mode for more than 5 minutes, it wouldn't start. Replaced the battery and problem went away. Recently when I went out to drive it, the power doors and all worked but when I tried to start it, it wouldn't turn over. Had it jumped the first time and it worked okay. Second time after jumping it and letting it run, it wouldn't start after turning it off. I'd appreciate your thoughts on this. Thanks in advance for your help.
Marc Rospert
May 8, 2008.

Check battery connectors
clean and tighten
check battery

May 9, 2008.