Hello,
I just bought the Anker powerbank “PowerCore II 10000” and tested twice:
the tester showed only 8326 mAh
Should I replace it?
Cheers
Simon
PowerCore II 10000
I’m interested in how you test your power banks. Do you need a separate a device?
No it’s normal. Amps are not meaningful without Volts and ultimately you must only measure Watts.
Watts is total energy flow, it is divided into (anology) the drop of a waterfall (Volts) and the width of the waterfall (Amps). These multiply to total waterflow (drop x width). You can alter the flow via stepping up the drop (narrow the flow) so you can alter the velocity of the flow via narrow the width of the flow. But total water flow is the same no matter the width of the flow.
So the 10000mAh is actually at 3.7V, so at 5V that is 7400mAh at 5V.
So the fact you measured 8363 means you probably wouldn’t have got 5V. Did you measure Volts? Did you measure Watts?
Going forward, measure Watts only, it is the only way to measure if a cell is good.
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Hello professor
thank you for your inputs.
The tester I used showed 8326mAh for 5.2V
It said 0A (it must be a bug) and unfortunately doesn’t measure Watts… (see attached photo)
According to an article I just read, the real capacity is usually around 2/3rd of the official one:
the 3.7V to 5V conversion + conversion resistance + heat waste (10% waste)
So if the tester is accurate, the score is very good…!
Get a magnifying glass and read off the Wh from your Powercore, it is probably 10000mAh 3.7V so 37Wh?
8326mAh 5.2V so 43.3Wh, which is too high, so I doubt you got 5.2V the whole time. Measure Wh.
Correct the ratio of output volts to cell volt minus a few % in heat, and so 2/3 is good rough calculation.
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The tester was plugged in the USB power adapter, not the PowerCore (see photo), while it was being charged.
I thought it would give me an accurate idea of the its capacity, but maybe not…?
The tester measures the voltage output by the USB connection, not the batteries themselves…
on the PowerCore II it says:
100050mAh / 36.18Wh
Input 5V - 2A/9V - 2A (18W)
Output 5V - 3A/9V - 2A/12V - 1.5A(18W)