Doesn't the bike suppliers information, give you typical ranges for their bikes/batteries ?
Whatever figures they give, I'd suspect they may be over optimistic/ideal and maybe exaggerating. So would expect the real life figures to be two thirds or a half, what they say. Maybe even less than that.
There could be good independent tests/reviews which give the range.
When the battery is down to 5% to 20% of left capacity, it may be too weak to drive the bike and/or a bad idea, as the battery could be damaged (excessively run down).
Also reaching 100% full charge may be problematic as well. Maybe 90% (if done very quickly) is more realistic. (It depends on how fast the charger is, battery temperature and other factors). With enough time, 100% is possible, I guess.
The motor drives and any voltage conversion (if necessary), will waste a percentage of the energy as well.
Accelerating would probably use the most power, I would guess. Heavy battery loads, can reduce the run time, even more, because of inefficiencies in the battery. I.e. Amp/hours ratings, depend on load current over a period of time. Very quick discharges, are usually lower figures.
EDIT:
I'd be scared of getting killed/injured on it and use a safer method of transportation.