Continuous battery amps vs phase amps

[Craney00]

If my battery can supply 300amps continuosly, and 420amps max discharge, will my max phase current be limited to 420amps? In the settings of stock controller, the manufacturer set max line current to 80a and max phase to 300, with the battery discharge being 90amps. Is this because of the split between 3 phases? Could i set my max phase higher than 420amps?

 

[bananu7]

If my battery can supply 300amps continuosly, and 420amps max discharge, will my max phase current be limited to 420amps?

No. Phase current isn't directly related to battery current.

Is this because of the split between 3 phases?

It's because phase currents occur on the equivalent impedance of the motor windings and motor back EMF, while battery current occurs using the entire controller as its impedance. Different equivalent impedances mean that a given power coming in from the battery in a form of some current at battery voltage might be used as a different value of phase current, at a lower, PWM'd voltage over the motor.

Could i set my max phase higher than 420amps?

You should set your battery current limit according to your battery, and your phase current limit according to how quickly your motor heats up in your use.

 

[Craney00]

No. Phase current isn't directly related to battery current.

It's because phase currents occur on the equivalent impedance of the motor windings and motor back EMF, while battery current occurs using the entire controller as its impedance. Different equivalent impedances mean that a given power coming in from the battery in a form of some current at battery voltage might be used as a different value of phase current, at a lower, PWM'd voltage over the motor.

You should set your battery current limit according to your battery, and your phase current limit according to how quickly your motor heats up in your use.

Cool, exactly what I was looking for, thank you

 

[E-HP]

If my battery can supply 300amps continuosly, and 420amps max discharge, will my max phase current be limited to 420amps? In the settings of stock controller, the manufacturer set max line current to 80a and max phase to 300, with the battery discharge being 90amps. Is this because of the split between 3 phases? Could i set my max phase higher than 420amps?

Most controllers don’t have an adjustable phase amp limit. They provide as much phase current as they can relative to the battery input. Higher powered controllers have an adjustable limit, usually 2x or 3x the battery current limit, in order to protect the MOSFETs. You should be able to max out the phase amp limit in most cases.
I’ve been looking for a good article that balances the technical with the conceptual examples that will allow most users to wrap their head around the concept. As a not so accurate conceptual example, think of a given moment where the battery up is supplying 50v and 10A to the controller, or 500W. At that moment, the controller is only providing 25v to the motor (WOT but the motor is accelerating). So 500w/25v = 20A going to the motor. 10 battery/line amps in, 20A motor phase amps out or 2x.