Scrounged up a couple parts I bought a while back for this specific project, but just getting around to it now. The Sky-Watcher EQ6-R Pro telescope mount uses a 2 pin GX12-2 aviator plug for 12vdc power. I bought a couple off Amazon earlier this year, and today I soldered up the 5.5mm x 2.1mm power jack after testing which pin is ground and which has voltage. (https://www.amazon.com/dp/B07DC7KP8H).
I made this to supply power to the mount from my Pegasus Pocket Powerbox, which I have on a 15mm rail and SmallRig aluminum cheese plate (https://www.amazon.com/dp/B019C2ZM8Q).
Here's the cable plugged into the Pegasus PPB, powering the Sky-Watcher mount. Tested and woks beautifully!