2015 Compass 2.4L Battery Issue
I'm looking for some advice/help/a starting point for the following issue that I've been having. First off, back in late August, my girlfriend's Compass wouldn't start one morning. The lights would come on when the door opened, radio came on etc, but just wouldn't start. Jumped in with a jump box and took it to Advance to have battery tested. Their 1st test said that everything was fine, battery had a charge, alternator and starter were both good as well. Next morning, same issue, lights on, wouldn't turn over, jumped it again and took it back to advance. Their test the 2nd time indicated that it was a bad/old battery.
We replaced the battery and have had no problems until yesterday morning. She went to go to work and it wouldn't start, same thing as in August(lights on, radio on). When I checked it about 5 hours later, it was completely dead, no lights no radio. I tried to jump it with the jump box, wouldn't turn over, tried jumping it with my vehicle, nothing. So I pulled the battery and took it back to Advance where we bought it.
They put their tester on it again, the battery was so dead that their machine would test the battery, but wouldn't print out the results( they ended up having to attach it to another battery so that it would print.) They said they would need to charge it for 3-4 hours so that they could test it again to determine if it was a bad battery in order for them to be able to exchange it for a new one. I went to pick it up earlier this afternoon and they tested it when I got there. The battery tested fine, correct amount of volts, cca's etc. I took the battery home, reinstalled it in the jeep and it started immediately with no issue.
Any and all advice is appreciated, again I'm just looking for some help in maybe figuring out what's causing the battery to be drained(lights aren't being left on overnight or anything like that) when the alternator is supposedly fine. Thanks in advance!