ORIGINAL: rpg711
a higher voltage with the same kv will result in more current draw, yes. But the max power of a 3s is 50%higher, so you can run less kv and get the same results w more battery life
Yup I was talking about if you were using the same motor/gearing. But yes, stepping down to a lower kv motor or gearing down will both help as you suggested.
Something my geeky post doesn't mention also is that not only are you getting 50% more raw rpm, but 50% more torque due to the (potential) more amp draw, so in essence you're more than doubling the effective power output. Here's an example:
Say on 2s your motor only draws 50 amps upon normal acceleration (as a rough guestimate of the average amp draw)...
2s lipo - 7.4v x 50 amps = 370 watts
Moving up to 3s or 11.1v and keeping the same motor and gearing (for simplicity's sake) your motor may draw 75 amps:
3s lipo - 11.1v x 75 amps = 832.5 watts
You're potentially able to get over 2.25 x the power just by going up 50% in battery voltage.
Double the original voltage by using 4s lipo 14.8v:
14.8v x 100 amps = 1480 watts. Just going from 2s to 4s lipo (double voltage) the motor is making not double, but 4 times the power!
This is assuming your motor can actually handle the amp draw and is geared to be able to run correctly without overheating.
Cool eh?