You don't need 50hr of battery life. If you're on a network, you're near power of some kind. Laptops these days use less than 10W in light usage and will run off anything with a USB power port.
This is a "solved problem" by the mainstream retail PC manufacturers...
> If you're on a network, you're near power of some kind.
Unless you're not, because you're using an LTE modem, or inflight wifi on an aircraft without in-seat power, or any of a number of other real world scenarios.
