I've been having an on going issue with my cars battery draining while parked. I had the battery tested and they tell me it’s good. I had the alternator tested and they confirm its charging properly. Here's what happens:
I park my car, locking the door as usual with the remote fob. When I come back to leave for the day, my flashers markers are flashing. I unlock the door with the fob; try to start the car and it just clicks. Dash fully lit up, radio will turn on, and lights will come on, but not enough juice to turn over. With a 20 min trickle charge it starts right up. I also jumped it via a jump box a couple times with no problem. I have put a volt meter on battery when it won’t start and it shows 12volts. As the car runs it shows around 14 volts. What could be draining the battery? How can I diagnose this further? Any ideas would be much appreciated.
This has happened parked in my garage for the night as well...