What does 'Kv' mean on brushess motors? Kv explained!

Ever wonder what "kV" actually means and how it relates to the operation of your brushless motor?

[joeleames]

Amazing video - answered a lot of questions I had. You talked about the number of turns as a representation of how fast brushed motors were (back in the day). The wire winds are around the armature instead of the stator. I'm actually amazed that brushed motors are still around considering how superior brushless are.

[ndrsg]

Thank you explained very well, clear and simple... Here a summary of what you mentioned:
Kv is equal to 100 RPM per volt
Note: Higher Kv losses torque.
Higher Kv motor runs motor faster
Higher Kv heats the motor faster

[Mark-rozg]

Thanks for the info. Surprising how quite the brushless motor is compared to the brushed.

[paultro]

You guys are my go to battery for all my RC's. Always had good luck with your products and I like that you have weekly sales. Anyway, thank you very much for explaining all this. I'm headed to watch the other video right now.🤙

[jasonranaweera]

Thank you so so much for this lesson sir! I just really found this useful. Keep up the good work!

[ocdraridrogonel]

thank you, very simple explanation helped me alot!

[rc_dude]

Just what i was looking for. Thanks. Staying for longer.

[dorianshepard]

I wish hard info channels like this were easier to find

[forgetfulLlama]

That was great.. really enjoyed that video. Thanks

[hondayamaha]

thanks for the explanation, I'm finding what is the right motor for rc boat. heating is not a problem since I have water cooling and propeller put less stress than car gears I assume. to higher kv it is. thanks alot

[bobbyspenser]

hey i am here watching this an i am building a lcg crawler an i an in the nurseing home i got hurt a while back an i am in a wheelchair an i needing a motor i am looking at the surpass hobby 3532 2250 kv outrunner motor an the castle mamba micro esc let me know if that is a good combo i see other people running the combo so let me know or make a video of the combo that i am wanting i an not getting in an comps or anything just out side here at the nurseing home so if you can help me let me know ok my friend an great video an i am going to watch your videos an see what else i can learn thank you for the great imformation an shareing this

[sewingmachinesindetail]

Thanks for this video. Depending of the software in the ESC, it could do SpaceVector PWM with a 1.15 times higher voltage than Sinosoidal PWM. What kind of ESC will the motor manufacturer presume, when they define the KV value?

[carscoffee]

Can you change the kv in a brushless motor?

[neilhabermehl]

The RPM of a 3 phase motor is determined by the number of poles and the frequency (Hz) of the AC. The displayed voltage did not change yet the RPM changed as you rotated the knob on the motor analyzer, so clearly RPM is not a constant with respect to input voltage.

What is the frequency range that the motor analyzer changes over as the speed control knob is turned?

[ebenwaterman]

Technically, the old "turns" spec. hails from DC motor days. Probably slot cars. It was used to simplify the motor specs for comparison purposes.

With DC motors the speed is limited by the back EMF the winding's generate when it is rotating.
If a 10 turn DC motor is spun (as a generator) at say 1000 rpm and generates 1 volt, then 1 volt will only be able to spin it a 1000 rpm.
If you wind it with 9 turns, it will only generate .9 volts. But, if you power it with 1 volt it will spin at 1111 rpm.
This is where slot car racers got their speed advantage because you couldn't raise the voltage.
This back EMF problem still exists with brushless motors.
I think. :)

[guypehaim]

It seems the Kv is written reversed. In math, we normally put the modifier after the name as a subtext: Vk.

[mangosouljah]

Hey, great video and very informative

However I am still not sure about my soon to be setup

Battery: 3s 2300mah 120c
ESC: 120a hobbywing rated for 2-4s
Motor: 2845 4300kv

Will the motor bottleneck and or not handle the rest of the setup?

[Fhd]

Would a 1200kv have more torque than a 2400kv motor? Is it better run a 1200kv on a super heavy Truck?

[patrickmuller]

so if i have an enien stup.. if calculated rpm (kv x volt = rpm) is much above actual max rpm under load it will drain the batterie ? and if the rpm are equal th ficancie will be good?

[m.a.s.hq]

Thank u man i have hobbywing 1800 kv on my axial scx10, just planning to upgrade to 2800kv but my concern was the torque, but after watching ur video i'm gona stick with my 1800 cuz i don't want to lose torque specially while crawling