Watt or current

[papajay]

let said an esc loaded with it maximum esc capability, ex: 100A and applied with 20v, so we have potential 2000W power,
then again same esc and load (100A), with 10v we got 1000W.
2000 and 1000 W is totally different beast.
So, what is the limit of an esc, watt or current?

[BrianG]

For the ESC? Current and voltage. An ESC is either on or off so the wattage dissipated by it is just the losses from the FET rdson, switching losses, and copper losses, therfore, very low. The voltage is limited by the various device ratings. But don't make the mistake of saying "if an ESC can take 6s and 100A, then it is rated for 2,200W".

Now, current and power are limiting factors for motors. The windings can only take so much current before they turn into a fuse. Motor efficiency and case surface area will determine how much power it can handle before it gets too hot.

[suicideneil]

Current, unless Im mistaken. The components are rated for a certain amount of voltage and current (amps), so all things being equal there will be a maximum amount of power (watts) you can generate before the current climbs too high (assuming you dont go over the rated voltage)- this could be because of excessive gearing or load causing the motor to pull too much current. Thats why its always best to use higher voltage and lower kv motors to generate the maximum possible/ allowable amount of power, as it keeps the current draw down resulting in lower running temps and greater run time.

[papajay]

Thank Brian, that clear enough, so the ESC is limited by the current.
How about the motor limiting factor, (if we change the question from esc to motor)
You said that both is limiting factor for a motor, somehow manufacturer list their motor only with current and other were using watt (like neu).
Again, 1000w vs 2000w is a huge difference.

[papajay]

@ suicideneil,
I was meant this in testing equipment, which we can keep all input in constant value.

[BrianG]

I have no idea why manufacturers put a current value on their motors, especially for car use. There is absolutely no way to get a constant current draw on a car motor; you'd have to do no acceleration/braking, and keep a constant speed with no variances in terrain, and do no turning.

Wattage rating is little better. Cars pull a lot of high current bursts, with much lower quiescent currents in between. You'd have to use something like an eagletree device to get average amperage and current (therefore power) and use that as a rough way to make sure your average power requirements do not exceed the motor's constant power rating. And even then, a motor's power rating can change with ambient air temperature.

[papajay]

I was intended to change motors data fields in my site, I'm a bit confused because data provided vary across manufacturer.