Well, any laptop is an internally-powered PC. But using that power to power other devices is self-defeating.
Alex, what accessories do you want to power? What are their power requirements? How long do you intend to operate between recharges? Consider how large a laptop battery is, and that is just to power the laptop. You would drain the laptop battery in short order if you used it to power both the PC and external devices. A mini-PC or compute stick would use less power, but an “internal” battery would utterly dominate the size and mass of such a device.
There is a reason people use external batteries to power their rigs. Current technology does not yet have such small batteries, even Lithium.
If you were to list the accessories you wish to power (and their operating voltages), people could help you estimate your total power usage. With that information, you could determine what size battery you needed to last over the desired operating interval. This would quickly show the unfeasibility of using a small pc to power itself and your accessories.
Edited by Dan Finnerty, 17 February 2020 - 01:21 PM.