just jump it.. I had the same problem.. I was working on my system the whole day/evening.. shoot.. it got dark out so I had to use my flood light that plugs into the cig lighter. After I was done.. I tried to start up my car.. and all I heard was clicking. ITs just the batt run down.. Just jump it and then drive around for a while.. dont worry bout it unless you gotta jump your car every time you wanna start it. then you gotta problem.. look for a power leak somewhere then. Maybe somethings not turning off when its supposed to.