On the Belgian Facebook group “AliExpress voor makers” I saw a powerbank pass by with quite a number of good reviews. It was advertised on AliExpress with the following flashy description: “TOPK Power Bank 20000mAh Portable Charger USB Type C PD 3.0 Quick Charge 3.0 Fast Charging Powerbank External Battery for Xiaomi“
I already knew what quick charge was, but I never noticed PD. I did not know what it meant, so I looked it up. Apparently PD 3.0 (which stands for Power Delivery) is a USB specification that enables the maximum functionality of USB by providing more flexible power delivery (based on the attached device) over a single cable.
This “flexible power delivery” translates into different voltage possibilities depending on the connected device. The TOPK powerbank can provide 5V – 3A, 9V – 2A or 12V – 1.5A. As the 9V and 12V options are interesting for powering the QCX transceiver, and you never can have to many power banks, I decided to order yet anther item on AliExpress…
A chip in the connected device tells the powerbank which voltage it wants to receive. If no chip is present, the power bank delivers the standard 5V USB voltage. The QCX does not have a built-in voltage chip, and 5V is not enough to run the QCX. So we need to use a what they call a PD Trigger. I bought several 9V version, as apparently, the 12V and 9V version are the same. To make a 9V trigger a 12V trigger you only have to put a blob of solder on the two jumper pads on the bottom (see red rectangle).
I took a piece of power cable, soldered a 5.5mm barrel connector on one side and the trigger on the other. Finished off with a bit of shrink tubing, and you have a way to power your QCX via the powerbank. Or at least almost…
Although on the back of the powerbank it’s indicated that all 3 USB ports can deliver the 9V and 12V, I could only trigger these voltages using the USB type C to USB type C power cable of my wife’s Samsung. There seems to be some extra intelligence needed in the cable which I’m not yet familiar with. Anyhow, there is not much you can’t buy on AliExpress, so I ordered my own USB type C to USB type C cable from UGreen to use with this new setup.
