Charging it twice left enough battery power in it to allow me to guess it may charge the iphone 4-5 times

I bought this for my dad, he was always having issues with his phone battery and now he is extremately happy thanks to this battery, he gets 4 or 5 charges to his phone and even his friends are asking him where he got it! it went from dead to 100% and the battery pack still had 14 percent charge left in it, which is about as good, or better than what you would expect for a 10000mah battery

When i tested the charging capacity with the ipad air 1, i used the 2

1a port and got the charging speed that you would expect