suggestion from me, buy pineng powerbank. even 11200mah pineng powerbank is more efficient than yoobao 13000mah.. if got extra money, buy 16800mah, the price 169-190. i saw on garage sale, have RM180. can charge more than 6 times. compare to 13000mah yoobao, only 4 times. price also almost the same.

edit:

forget to tell, i have both. use both for different purpose.

i will use pineng if i want to normal charging because output 1A and 2A. 1A is almost the same like wall charger, can charge phone within 2.5 hours to 3 hours. never use the 2A because worry to damage the battery.

then, i use yoobao if want to fast charging using 1.5A output. can get 2 hours to full the battery from 5%. since it only 1.5A, not very worry. the temperature is almost the same like using wall charger. the only different, the voltage. slightly higher compare to wall charger and 1A pineng. 1A pineng is same i guest. but 1A yoobao is so slow. the current show 999mA, but the voltage is lower than wall charger that the reason it charging phone slow.

i suggest download current widget to see the current and voltage, also the temperature when charging. to protect battery, never use the charger that have voltage 0.5v higher than wall charger. if lower still can accepted. normally, wall charger on 100%, the voltage is 4.2v. be in mind, different battery level, different volt.

eh? reason? still under warranty right? how much?

why sell bro? Upgrade S4 LTE?