I had a problem in Jan/Feb this year like you have and it turned out to be my original battery terminals (they had become conical shaped over the years) I suppose from removing to reboot or clear a cell. They apparently were only making good contact with the battery terminal near the top and "coned" away from the terminal going down the battery post. I put new terminals on (regular style ones from advance/autozone??) and haven't had a problem since.