Vesc setup motor max current??

[electricboard1]

I have a 48v 1000w motor and a 48v 13 ah battery (which has a 30amp bms)
I have a Flipsky 75100pro V2 controller which I am just trying to setup
On the settings page I have set my battery amp to 28amp to keep the battery safe but just wondering what should I set the motor current Max value at? and also the absolute motor Max current ?
When I ran the Vesc setup test it says my motor current is 86.76amps

So in the Vesc app should I set the motor max current to about 85amps? Or should this value be much lower if I only have a 30amp bms on my battery?
Also what amps should I set the absolute max current to?

 

[scianiac]

Realistically setting it to twice the battery current will about use all of the 28A from the battery but you can set it a bit higher as well assuming things like the phase wires on the motor are up to snuff. The motor current is the phase amps so the current going into the motor so ideally you should set it a bit higher than the battery amps, make sure nothing is getting to hot (probably not considering the motor size) then increase it and repeat. At some point the battery current will be the limiting factor so setting it any higher won't do anything. You just don't want to get anything too hot, motor windings and phase wires. The 85A it recommended is just based on whatever you selected in the wizard and is just an estimate based on the motor size.

So the phase current will be higher than the battery current, when the battery is supplying say 20A the phase current may be 40A and that determines how much torque you have and how hot the motor gets. So if you set both limits to 30A the battery will only be supplying like 15A (depending on speed) so to use all the battery power the motor current must be set higher and at some point the battery current limit will be the limit all the time. Just want to make sure as you increase the phase current nothing is getting too hot, although we aren't talking crazy current levels for that motor so probably will have no serious issues.

Absolute should be set around 1.5 times motor current but setting it to something like 1.1 times and testing things to make sure you aren't getting any overcurrent faults (motor will cut out for a few seconds) at first then setting it to 1.5 if the motor seems to be running nicely.

 

[chuyskywalker]

The primary limiting factor on phase amps is what the controller can handle, what size wire you've got running to the motor, and how hot it's gonna get the motor.

If you have a temp sensor in the motor, you can ignore the "how hot" and lean on power back-off from the VESC platform.

After that, you can just set it as high as your cables/controller support. You'll get all the torque you can eek out of that controller, and when it starts over heating the motor, it'll scale back to the max the motor can handle for whatever situation you're driving it in.

If you don't have a temp sensor, then you might need to lean on the motor manufacture's stated values or other know-good values. For example, if it's called a "72v 5000w" motor, then you can divide that out and roughly assume it can handle about 70A and go with that.

But, generally speaking, it's just about how much heat the components can handle.

Or should this value be much lower if I only have a 30amp bms on my battery?

You don't need to worry about that; battery amps take precedence. You could have the phase amps set to 5 billion, but if the (voltage X amps) on the battery side is N watts, that's all the power the controller has on the phase/motor side. At that point, it's just the math of the motor's Kv (rpm/volt) that affects how many phase amps are going that direction.

 

[neptronix]

2-3 times the battery amps value, adjust to taste

 

[electricboard1]

Thanks all