Big problems of battery for the Galaxy S4?

Galaxy S4, in addition to displaying sales figures deca those desired by Samsung, is plagued by serious concerns battery.
Some users of the Samsung Galaxy S4 complain effect of battery problems . Sometimes these will display a paltry autonomy. In other cases , more serious this time , some batteries have "inflated" substantially, clearly pointing to a degree of danger.
Fortunately , Samsung has already noted this problem, and said in a press release :

    "We are aware of this problem, which affected a limited number of users. [ ... ] We urge all those affected by this desire to visit their nearest Samsung center , where they can receive a free replacement battery . We remain committed to deliver the best user experience for our customers . "
Obviously , almost 30 % of users Galaxy S4 would potentially affected by this concern . This, it must be said , has nothing to do with an isolated problem.
Users Galaxy S4 , have you faced this quack ?