I purchase this power bank to charge my phone but at bill box it's written it will charge 4000 mah battery 3 time but at one time the charging of power bank get low and when I call customer servers they are not picking my call and Im in loss by takin this power bank if you all are looking for power bank don't buy this buy different but not this one because I'm totally in loss situation.its just a name billion but in real it just charge one phone .