Question about Amp draw

[brushlessboy16]

I am having a little dispute with a freind.....

We are trying to figure out what draws the current from the battery....


My freind is trying to say that the esc is always drawing the same amperage at ALL times, and all stages of throttle.

And im saying that the ESC only passes as much as the motor need at that time..

can someone clarify?

[BrianG]

Your friend is incorrect. The ESC puts out a PWM (varying pulse widths) voltage which is proportional to throttle setting. The more throttle, the wider the pulses. Narrow pulses sends lower average voltage to the motor, wider pulses sends higher average pulses to the motor. The motor will pull whatever current it needs to reach the rpm for that voltage, which is determined by the motor kv. So, if you gently throttle, current is low. Mash the throttle and the current is very high. Any eagletree graph will confirm this.

[Takedown]

Haha, Dude you went threw all of this to prove to me something I already knew BB. I was just trying to get you fired up and to see what proof you could find. I was laughing the whole time. Hope you forgive me.

[brushlessboy16]

so the esc will only push what the motor needs? correct? in that case lets say a 2amp battery, 10 amp esc and 2amp draw motor, the motor will only ppull that two amps right?

[Takedown]

Well yes because were would the other 8amps come from? It would highly strain the battery and that is why you never run lipos with lower amp draw than what the motor does amps continious. Infact I would run a much higher amp lipo just incase.

[brushlessboy16]

if the motor only needs 2a thats all it will take is what im saying

[VintageMA]

Originally Posted by brushlessboy16

if the motor only needs 2a thats all it will take is what im saying

Yes, that is correct. The amp rating on the ESC is only telling you how much current it can pass without overheating and burning up it's own circuitry.