most shipped with around 80% battery. battery % indicated on the LEVELS screen in the upper right.
different engines/scripts use different amount of CPU hence different amounts of power. you can see the power drain by holding KEY1 in LEVELS. the battery is 2250maH so you can do the math of how far you’ll get given your current consumption. (it also shows charge rate, as a positive number)
and no, there’s no indication when charging when the thing is powered off. unfortunately there wasn’t a quick (cheap) way to implement that in the circuit.