Drone (Mavic 2 Pro) is, for example, 5 km away and the battery level indicator is approaching toward the "low" mark. You want to fly back the drone to you as safely as possible. Do you use the max battery speed or max distance speed?

Max battery speed 25 km/h = 7 m/s = 15.5 mph = 13.5 kt
2.4 min/km = 0.42 km/min
Max distance speed 50 km/h = 14 m/s = 31.1 mph = 27 kt
1.2 min/km = 0.83 km/min

Ignoring wind direction, the optimum speed and power consumption will be the figure DJI state as giving maximum flight time for the battery.
Hovering and full speed on sports mode, if you have it, use more power than optimum. Obviously, hover and slow speed will consume more power for distance covered. Speeds above optimum may get you there quicker, but because of drag, faster speeds use disproportionately more power.

For those with Mavic Pro, perhaps other models as well, sports mode doesn't make more power available to the drone. Think of normal/sports mode like a maximum speed governor, not an accelerator. For example, if you were flying into a strong headwind or even lifting a heavy load, the system allows as much power as it is capable of to achieve the speed and lift the sticks request.

AlansDronePics Posted at 7-11 00:47
Ignoring wind direction, the optimum speed and power consumption will be the figure DJI state as giving maximum flight time for the battery.
Hovering and full speed on sports mode, if you have it, use more power than optimum. Obviously, hover and slow speed will consume more power for distance covered. Speeds above optimum may get you there quicker, but because of drag, faster speeds use disproportionately more power.

For the Mavic 2 Pro, the same distance flown at 50 kph uses 27% less battery than flown at 25 kph.
So it looks like the 50 kph is the safest speed to bring the drone back.

djiuser_PvNSuz4JK8bY Posted at 7-11 02:27
For the Mavic 2 Pro, the same distance flown at 50 kph uses 27% less battery than flown at 25 kph.
So it looks like the 50 kph is the safest speed to bring the drone back.

It would seem so, wouldn't it. Odd DJI don't use that figure to maximise their battery performance. They dropped the ball on that one.