I am using mi powerbank 2i of capacity 20000 mah .which gives us approximately 17to 18000 mah power to charge any phone, tablets.etc.The main thing is that it comes with one microusb and two usb ports.and also it supports reverse charging.so my suggestion is only that xiaomi is a good company which manufactures best budget electronic products under reasonable price.This is great powerbank and you should use it once.Thankyou.
Why you are dissapproving the reviews without any reason.