The battery is specified with 13,000 mAh. My Samsung Galaxy battery with 2600 mAh. I can my phone when switched off only 2 charge times. I am well aware that is lost in transmission and voltage conversion energy ... but not so much! 2600mAh + 2600mAh = 5200mAh ie less than half of which is indicated on the battery. Moreover, not even the excuse is one of the battery several times before to be fully charged (in my case 12 hours). I have the battery fully charged multiple times. Can not recommend the battery already better noname China had Products