Since the original battery of my XPS 15 already after a few months use showed very strong wear and has hardly held for one hour after full charge, I was looking for a replacement battery and here found it. The battery fits perfectly with the XPS 15 (L501X) and holds over the original very long through. The only drawback: The laptop is equipped with this battery a little heavier and will only fit kanpp in the NB-pocket.
I do not know how is the battery life, but I hope that he does not wear as fast as the battery purchased from Dell.
For price offered the battery is a genuine alternative to expensive original Battery from Dell and is a clear Kaufmfehlung for those who are looking for a cheap replacement or second battery for your XPS 15.