Do you know the real capacity of your power banks?

With the development of mobile phones, especially iPhone and Samsung, the phones with big battery which could last long time has been the past and people prefer mobile phones with delicate design and slimmer size . As a result , power banks become a must in our daily life .

In order to get more benefit , many sellers with no brand start to make fake power banks. 

So how do you know the real capacity of the power banks you bought without any professional machine ?

Before identifying the real capacity of your power banks , we need to know how to calculate the capacity of a normal power banks.

When we buy a power bank from Amazon , we will see some technical details on the power bank or its package like this 

Here, you can see 

-the capacity of HAME-H16  is  11000mAh

-Input    5V 2A  (this is for testing the speed of re-charging )

-Output 5V 2A  (this is for testing the speed of charging your phone )

Notice: all the capacity marked on power banks is tested under 3.7V while the voltage is 5V when you're charging your devices.

So the real capacity when you're charging your devices is 11000*3.7V/5V=8140mAh

In real life , we also need to consider the electricity loss when we're charging , so we should consider conversion rate which is also a standard to evaluate a good power bank.

For this power bank HAME-H16, the conversion rate is above 90% , really high. 

Then, the electricity you can use to charge is 8140mAh * 90% =7326mAh

Now we can test , if we use this HAME-H16 to charge an iPhone6(s) （the battery of an iPhone6(s) is 1700mAh ) , we can charge 7326mAh / 1700mAh =4.3 times

So if the power banks you bought cannot charge your phone at proper times according to the results you calculated, maybe the capacity of your power bank is fake.

Next time , we will discuss the speed of charging and recharging of a power bank and how to identify good power banks before purchasing .