Made a power bank. But it charges so slow! Questions!


Newly Enlightened
Oct 8, 2017
So I was bored the other day and made a power bank at work. I still need to make a case for it and streamline it, but it works. The only issue I'm having is that it charges the battery pack so slow through the micro usb! It's the usual style 1S setup. But I decided to use 20 cells in parallel.

So my questions are:
1.) Are any of those fast charge circuits on eBay promising QC3 real? That's more about the output. But some promise "fast charge input" but even then I feel like 2 amps isn't quick enough. Are any true QC3.0 that are legit?

2.) Should i make a port to connect it to a fast/smart charger? Any that someone could recommend for 1S that won't break the bank?


Flashlight Enthusiast
Dec 28, 2015
Vilnius, Lithuania
Perhaps, you don't realize severity of the problem :) 20 cells in parallel capable of 1A charge current each... You need a 20A power source. 5V*20A=100W. The most powerful wall warts I know are capable of 18W only (AUKEY PA-T9, ANSMANN 130Q). Both are Qualcomm 3.0 capable. But both drop output voltage at high load. Most funny that AUKEY is better than ANSMANN in this respect. I have purchased both to power ASUS Tinkerboard with eMMC. The Tinkerboard reports low voltage with both wall warts, but shutdowns on low voltage with the ANSMANN only.

All other non-stationary chargers produce only 2.4A per outlet maximum.

To get stable 5V at 3.5A you need something like this:
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