less since the charging and discharging comes with a lossDepends on when you start charging it. But since the X is rated to have a design capacity of 2716 MaH (if brand new). I'd say 1 full cycle and 85% of the next cycle.
You've got one, test it and see
got an anker one works great
Haha I didn't think of that. I charged the external battery, then charged my iphone from like 19% to 100%, and I don't think it used much of the external battery at all.
I use a 24500 mah power cell