Charging problem

If your charging system is putting out 13+ volts that shouldn't be the problem. Normal is about 13.5-14.2 volts. Even though Sears says it load tested good it sounds like a bad battery. I had one in my 93 Dakota do that. It would go for 2-3 days and start fine then all of a sudden it would be dead and I'd have to jump it. Then it might work good for a day or 2 again then it would be dead again. First one I ever saw do that. I changed the battery and never had any more problem. Do you have another battery you could put in it to try it? That would tell you if it is the battery or not.