> What happens to a Segway when it runs out of battery?
A Segway needs electricity to balance itself, so my guess is that when it gets close to running out of battery, it stops by itself and refuses to continue.
From trading the other comments, it seems the Onewheel is just glitchy. They certainly must also have a low-battery cutoff, but I bet it's not accurate in all ranges of temperature and with aged batteries.