I had the battery tested and its fine (Its not even 3 years old) but something keeps draining the battery if I don't drive it for 3 or 4 days. I've checked and nothing is left on inside so I don't know what it could be. I heard this is common with Jeep Grand Cherokees but I don't know if its true.
@ Mike S - I had the cells checked and they were all fine. The battery indicator on the dash is always around 14 or a little higher.
@ Sammy the - I always buy Interstate batteries because that's the kind my brother sells at his service station. The one that's in the Jeep now is an Interstate Master Series.