Understanding Kv ratings ?

[ranchhand]

Hi,
Can someone tell me why two motors with the same Kv rating can draw different amps? Both were 3cell, but one is around 35amps and the other 52amps. Is there another number? Maybe a measurement of horse power?
Any help would be great.
Thanks

[Cheetah62]

Yes, it is a measure of power (barring any electrical or physical defect).
Having the same Kv rating does not make the motors the same.
A 3s motor drawing 52 amps is pulling somewhere between 550 and 625 watts, depending on the actual battery voltage.
Nominally, a 3s pack is around 11 volts so 52 amps would be about 575 watts.
The 35 amp motor is pulling just under 400 watts at the same voltage.
One motor is more powerful than the other, probably by design. Check the specs on them and see what the manufacturer lists as the rated power in watts.

The Kv rating only tells you what the design speed (RPM) of the motor is for a given voltage.
Two motors with the same Kv rating should spin at the same speed at the same voltage under zero load, but one may be more powerful than the other and designed for a heavier application.

[ranchhand]

Cool,
Thank you very much!