2003 Kia Sedona Battery Problems

2003 Kia Sedon - I have had several problems with having to have my battery jumped especially if I had left my lights on for a very short period of time or radio etc. w/o car running. I have had the battery and the alternator checked and both seem to be in ok condition. One mechanic told me he just tightened the terminals and everything appeared to be OK. I also had my cousing checkout with his meter and told me the same. I am not sure rather to just get a new battery altogether or should I take it in to the Kia dealer to have it checked out. Any suggestions?

I suggest you find the right forum.