Battery saving optimal speed for a quadcopter

[MaxBuzz (Maxim Buzdalov)]

Various companies are publishing cruise time > hover time, including those whose quads have symmetrically located propellers. I have heard various explanations, such as:

• hover has to use its own, partially turbulent air after some time due to air circulation around the craft, while a moving craft can use fresh air;
• hover has to use more frequent rotor speed changes than cruise, since cruise is not that sharp about holding a particular position.

Which one is true/more likely, I think, depends on the particular craft, from motors to control algorithms.

[Allister (Allister Schreiber)]

@MaxBuzz

hover has to use its own, partially turbulent air after some time due to air circulation around the craft, while a moving craft can use fresh air;

Yes, we’re saying the same thing. That’s basically translational lift.

[cbf123 (Chris Friesen)]

@OldGazer

Equating this to aircraft performance is futile… In a quadcopter you should be looking at endurance (flight time) and not speed. In this regime, light frames with low KV motors swinging “big” props rule.

While I agree with the light frames/low KV/big props, flight time and distance covered are two separate things and can be optimized separately. When optimizing for distance covered it is beneficial to travel faster as long as the power consumption goes up slower than the airspeed.