How many times can a 20000mAh power bank fully charge your phone? Let’s take EasyAcc 20,000mAh power bank as a test example.
Actually, how many times can a 20000mAh power bank fully charge your device, smartphone, tablet, Gopro, even a macbook, is relevant to 3 primary factors.
#1 what device you wanna charge with a 20000mAh power bank?
The first factor is about how much capacity your device’s battery is.
Generally speaking, a good rule of thumb is to divide the mAh of 20000mAh power bank by the mAh of your device battery.
So a 20000mAh power bank can “theoretically” charge an iPhone 6 plus from 1-100% 6.9 times (20000 / 2915 = 6.9).
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.
#2 what is the device doing while it is being charged
It’s not strange to see the device charged, for example, by a 20000mAh 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 20000mAh power bank is charging it, more power drained from the 20000mAh power bank and meantime it seems that your device is never charged. That is because you’re taking the power more quickly than the 20000mAh charges your device. And the number of times your power bank 20000mAh would reduce.
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 20000mAh power bank is charging up the device.
#3 The charging cycles of the power bank 20000mAh
More charging cycles the power bank has taken, its capacity will correspondingly reduce a little though you don’t need to care about that.
Theoretically, the capacity will reduce to 80% after 300 charging cycles. If so, a 20000mAh power bank may have a 16000mAh 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.