A little math on the electric motors

[balvardo]

Greetings to all.

Briefly formulated question that encouraged me to write this topic - I can not find a motor for my project.

I will not write something like "I am building a mountainboard, with rear wheel drive (with two engines), I want to accelerate to 40 km / h"

On the description of the motors I see such interesting options as

Kv - clear
Turns - example "8T" - what does it mean?
Voltage: 4 ~ 8S - what the "S"
Max Current: 90A -?
ESC: 100A -?

I would be very grateful if someone finds a few minutes to explain how all of these parameters are related to each other.

On the other hand, if we look at the finished projects, and there is usually written in the format of motor power 3kW. And how does this compare with the previous parameters.

In general, if someone finds 5 minutes to educate about the mathematics of this process - I will be very grateful.

 

[psychotiller]

Kv - Is the revolutions a motor makes per volt.

Turns - example "8T" - what does it mean? (I stole this from another forum) Generally, higher turns + lower RPM and current(amps) higher torque, less turns = higher rpm higher current and less torque but more power I.E.High turn motor high cubic inch big block V8 or low turn motor small cubic inch Formula 1 V10

Voltage: 4 ~ 8S - what the "S"? S is the number of cells in the battery pack. I.E. 1s=3.7v, 2s=7.4v, 3s=11.1v, 4s=14.8v, 5s=18.5v, 6s=22.2v, 7s=25.9v, 8s=29.6v

Max Current: 90A -? Max current is the limit of amps your esc or motor can handle.

ESC: 100A -?

 

[spinningmagnets]

Here's a good starter: http://www.electricbike.com/motor-tech-learn-the-terms-part-1/

These motors are rated as if they are going to be used on a light RC airplane that will accelerate faster than what we are using them for. Use the motors that have worked well for the exact same applicaytion that you are going to use them for, same with the ESCs, plus...add extra input ripple capacitors (a minimum of two, they are only $2 each, do it...and don't let anyone talk you out of it).

 

[drew12345]

Great article!

 

[arkmundi]

Here's a good starter: http://www.electricbike.com/motor-tech-learn-the-terms-part-1/

Thanks for that bit of education - learn more all the time spending time here.