2S vs 3S run times?

also you have to remember that the 3100mah 3s battery has 34.41 watt/hours of power and the 2s 4200 has only 31.08.

which to me means if you were to gear down so that the top speed was the same with the 3s pack and you were not running the motor at too high an rpm as to the extent of not effecting the efficiency of the motor significantly then i suggest that you would get an increase in runtime with the 3s pack.