How many times can a 5000mAh rated power bank charge an iPhone 6?

How many times can a 50000mAh power bank fully charge your iphone 6? Actually, this is a difficult question to answer.
The number of times a 5000mAh power bank can fully charge your device is relevant to 3 primary factors.
— What device you are charging with a 5000mAh power bank —
Generally speaking, a good rule of thumb is to divide the mAh of 5000mAh power bank by the mAh of your device battery.
So a 5000mAh power bank can “theoretically” charge an iPhone 6 plus from 1-100% 2.7 times (5000 / 1810 = 2.7). --iphone6 battery capacity is 1810mAh
Keep in mind: this is never 100% accurate as there still some other factors involved which will influence the charging times, which is always higher than what a 20000mAh power bank can practically give. Keep reading…
— What is the device doing while it is being charged —
It’s not strange to see the device charged, for example, by a 5000mAh power bank, while you’re still using the device. So is there any difference between using the device while it’s plugged into and leaving the device alone or on airplan mode while it’s charged? The answer is undoutedly YES.
If you are watching a movie on your device while the 5000mAh power bank is charging it, more power drained from the 5000mAh power bank and meantime it seems that your device is never charged. That is because you’re taking the power more quickly than the 5000mAh charges your device.
If you leave your device alone or on airplan mode while charging, you will get more fully charges since the device is not taking much battery charge at all while the 5000mAh power bank is charging up the device.
— The charging cycles of the power bank 5000mAh 
More charging cycles the power bank gives, its capacity will reduce. Theoretically, the capacity will reduce to 80% after 300 charging cycles. If so, a 5000mAh power bank may have a 4000mAh capacity. This is also relevant to the temperature when you’re using your power bank. And this point I believe you could find out on the manual when you brought the power bank.
As you can see, this is a very difficult question to answer. But I hopefully the infomation given here will be helpful.
And welcome all to comment below or share to facebook and twitter for more charging tips.
More you can see at my power bank blog: Power Bank