09-28-2019 03:11 AM
I had very similar intentions, and did loads of testing.
On my 7 black removing the internal battery works with external power but you don't get cloud upload, because the camera never thinks that it's charging.
I actually had it working with the internal battery with a powerbank too (generic chinese one). The trick is that the powerbank needs to have a drain to stay on. If the gopro finishes charging and is idle without much of a power draw, most battery banks will shut off. Then the gopro is down to using it's own power, which might be the behaviour your're seeing.
The bigger problem for me was that when the gopro is recording and charging from the PB at the same time, my external audio is mute!
Perhaps bad circuit design, robbing too much power from the mic amp circuit.
So for my scenario I had to remove the internal battery.
I've also done it a different way before, using 18650s via a little usb protection/charging module, feeding a boost converter module (battery voltage to 5v) that's always on, giving 5v. This method works fine but you need a manual switch between the usb charger module and the boost converter. The boost converter is always drawing power whether the gopro is on or off, and will eventually drain the cells.