In this article I want to show you some tests made on a power bank made by AUKEY:

12000 mAh Solar Battery Charger

Its model number is: PB-P8

And these are its main power features:

  • Input: a micro USB input port that needs 5V and recharge the power bank with a maximum current of 2A
  • Output 1: a female USB port that provides 5V up to 1A
  • Output 2: a female USB port that provides 5V up to 2.4A

Like every power banks these features are ideal but in a real condition greater is the current drained from a port and greater will be the voltage drop on that port.

This obviously happen also to this power bank but thanks to the variation of its ideal values you can determine the quality of a power bank.

Some times ago I have tested some low quality power banks and the results was high self discharge, 5V of the output port very bad regulated, sourced current lower than the expexted and a very low capacity respect the declared capacity.

This from AUKEY ( that is a good brand) works well and now I’ll show you some test resuts.

The first test consists to drain 1A from the Output 1, measure the voltage drop on this port and for how many minutes the power bank works.

This is the voltage on Output 1 when it source 1A, you can see that the voltage fall from an ideal 5V to a 4.472 mean voltage value

the power bank works in this condition for about 8 hours and 40 minutes

In an ideal condition a 12000 mAh power bank should works 12 hours draining 1A of current but you must consider that:

  • 12000 mAh is the full capacity of the batteries inside the power bank and they don’t use all its capacity when discharged
  • Battery voltage must be converted to 5V of the Output and in this process some power will be lose

at the end this power bank has an efficiency of about 70% that is good!

let’s continue with other tests.

The following screen is the voltage on Output 2 when it source 500mA, you can see that the voltage fall to  4.832 mean voltage value

In this condition (500mA output) the power bank works for about 17 hours and 20 minutes, this mean an efficiency of 72% as for 1A output on Output 1

Now take a look to this screen of Output 2 when it source 2A, you can see that the voltage fall to 4.254 mean voltage value

With 2000mA output the power bank works for about 4 hours and 8 minutes, this mean an efficiency of 69%, little less than the previous tests

So at the end PB-P8 presents an efficiency about 70% that is a good value

the outputs presents a voltage drop that should be better but for its primary function that is to charge  smartphone batteries I can only say that is a good power bank

also the output waveform is pretty good, no high ripple and no too noisy