Car Will Not Start problems of the 2008 Ford Expedition

Drove to work all appeared to be fine. After a 12 hours shift returned and vehicle would start; dead battery. Replaced battery, as it was original, and all was fine. I remembered that during the week prior to this the driver's seat would not automatically adjust when the key was inserted into the ignition. This was around April 2014. All was fine until again I went to work, 12 hour shift, returned and there was no response upon inserting the key into the ignition. Battery gauge needle did not respond and when the key was turned there was no response. A jump pack was connected to the battery and the vehicle was started without any problems. The vehicle was driven, started and stopped five times with no problems. As before, for the past week or two leading up to Aug 5th, I noticed that the driver's seat would not automatically adjust when the key was inserted into the ignition or removed. The seat adjustment controls do work. On the morning of Aug 6th the vehicle again would not start and it appears that there in not sufficient charge on the battery. (battery gauge had shown that it was being charged) I did hear a constant clicking sound which I found to be coming from the power distribution box under the hood. It appeared to be coming from the fuse or relay that is in the spot marked 55, it is grey in color and marked 5c3t-14b192-aa over p6std. I noticed that when I tried the driver's seat adjustment controls the sound would go away and when release the sound returned. Upon connected a charger to the battery the sound also went away. After charging the battery vehicle was able to be started.