Apparently too old?

The delivery was super fast, unfortunately the battery, however, did not know what I promised. According to various descriptions of the battery after the first charge while the unit and without the use of mobile phones could keep 10 to 14 days until the next charging must. But he has only 4 days, so only a little more than the old battery levels. Too Bad.
Villeicht the battery has lain too long in the camp? ... No Ahnung- So wars unfortunately a bad buy