Charging via USB

[tophneal]

So it doesn't take Any charge at all while running if its below 2 amps?

Regarding USB C (if this is true) then the same goes for USB C?

A running PBP takes 2 amps or so from the internal battery, more if the screen is full brightness and more if you added an NVME internal drive or any external USB device.

If you connect an official barrel 3A charger to a running PBP most of its charge current actually runs the PBP with only a bit left over for the battery so the charge level indicated will be slow to change. Worst case is - even with a charger connected the battery percentage drops with use.

The charger electronics within the PBP won't draw more than 3 amps so even connecting it to a 10 amp charger it will still take a maximum of 3 amps which may or may not be enough to charge a working PBP on high screen  brightness.

If you run the PBP with an external screen and you turn the PBP screen to minimum brightness then you can charge the battery better from barrel or USB-C charger.

Okay,
so does that mean that even if charging through USB via barrel input on less than 2A, it will still charge the battery with it only it will not charge as fast as it depletes the battery?

It'll be a slow charge if the PBP is not in use/powered off/suspended. If it's in use, you'll likely see a slower power drain.