Any fuel is good until depleted ....no planes / ship / trains operate with only enough fuel to get from A to B ...An electric motor can generate max power till energy is depleted ... no difference ....when the "fuel" is gone its gone regardless whether speaking of aviation fuel or electric charge ...
Currently, energy density of conventional fuel is greater per unit of weight than equivalent capacity of battery storage for the same weight but the tech is getting better. Electric motors have also continue to improve significantly - more power/torque for given size /weight and have significantly longer service life between overhaul ...ic engines not so much as the tech is essentially unchanged for last 70 years ...turbos / supers / fuel injection ..... biggest gains due to improved manufacturing and electronics .... It may be that the IC motor has had its day .....but they're still a thing of incredible engineering[/QUOTE
Electric motors are definitely less complicated and should theoretically last longer between overhauls than a IC prime mover. They do not however generate maximum power on a depleted battery. An electric airplane on final approach with a depleted battery would have great difficulty doing an emergency go around at max power to avoid something, whereas a recip or turbine would have no problem as it doesn’t matter how much fuel is available in the tank as long as there’s enough to last for the increased power demand.
If you don’t think that’s the case, try cranking your diesel truck over with a battery at 20% or try driving a 3” screw into a post with your battery drill with one bar on the battery indicator. Battery powered anything is fine until the battery is depleted. The laws of physics can’t be ignored because you’re using green energy. If that airplane has an immediate demand of 500hp to stay in the air and there’s only the equivalent of 250hp left in the battery, it’s screwed.
With a battery, depleted may mean not less than 20% charge remaining ...with a fuel tank it may be considered 5% to 10% of volume because below a certain level it will likely draw air ...either way when there is no fuel a motor, whether ic or electric, will be compromised ....