I am no mechanic but maybe someone can give some advice. I am on my second battery this year on my 2013 650 GT., The first one I replaced because I thought it had died the second has reacted like the first, after several days of non riding it will not crank and gives every indication of very low battery but it shows 13.8 on my volt meter. When I jump it it starts and runs fine and restarts the next day But leave it for several days and it won't start and acts like a dead battery, Its a mystery to me and never happened prior to this ridding year. Any ideas?