As a super smart guy since you have learnt math and physics at school, you sometimes should be or will be wonder,

Why the capacity of power bank always less than my calculation?

Yea, the calculation is very simple:

10000 mAh power bank recharge a phone battery of 2000 mAh

That is :

10000/2000=5 times

Oh, it is mathematic true, my friends.

The reality true needs another data: the Conversion Rate.

What is the Conversion Rate?

You see,

The electricity coming from the battery in power bank,

and when it passes through the mainboard in power bank, it loses some.

when it passes through the cable (especially the bad ones), it loses some.

when it passes through the mainboard of your phone, it loses some.

As a super smart guy as you,

Yes, I know your next question:

What’s the standard of the Conversion Rate?

The answer is: 60%.

It’s the standard in the battery industry.

So, the reality is like:

10000/2000*60%=3 times

Yes, only 3 times.

As a super smart guy as you,

Yes, I know your next question again:

What’s the standard of your Charmast Conversion Rate?

Well!

That is 75%.

So, the Charmast reality is like:

10000/2000*75%=3.75 times

Emmmm.

0.75 times is enough for a emergence I think.

Class over!

Have a good day guys.