The problem is the battery, if you use your controller while it charges, it slowly messes the battery up, after a while it will not hold a charge and it will die as soon as you turn it on after hours of charging. Your best bet is to buy a new controller as replacement batteries can't be bought from Sony, only third party sellers. You should buy 2 controllers and use one while the other is charging. PLEASE DO NOT USE YOUR CONTROLLER WHILE IT IS CHARGING!!!!