Vesc setup motor max current??

[AC-EUV]

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

 

[AC-EUV]

Thanks all

 

[TPEHAK]

I have a 52V (14S) 80A battery and I want to set the VESC controller to 80A to have more power, but the VESC Tool application does not allow me to set the current more than 60A. Is there any way to set more current and more power using the VESC Tool?

You can see on the screenshot from the VESC Tool application the symbol "+" against the Current Max is grayed out and inactive at 60A. I need more power.

 

[scianiac]

Is 60A the battery current limit for that controller? As in typically VESC firmware will have a hard coded current limits based on the hardware design and you would need to flash a "no limits" firmware version to get around it. What is the phase current set to?

 

[TPEHAK]

Is 60A the battery current limit for that controller? As in typically VESC firmware will have a hard coded current limits based on the hardware design and you would need to flash a "no limits" firmware version to get around it. What is the phase current set to?

I am sure this controller can easily go up to 100A battery so I would say 100A is the battery limit. But I need to set it to 80A because of I have the battery with 80A BMS.

I flashed the Luna M600 Ludicrous V2 firmware dumped from a Luna M600 Ludicrous V2 controller. Is there no limit Luna M600 Ludicrous V2 VESC firmware? Where do I take it?

I do not know where the phase current settings are, it does not show the phase current in the VESC Tool menu.

 

[scianiac]

Honestly it looks like that luna app they just did changed everything and hid everything they could to stop people messing things up so I have no idea where the phase current would be, the tabs aren't even the same. I assume you can't connect with VESCtool? And because they never released the source code like they should have you probably won't find a no limits firmware.

 

[TPEHAK]

I can connect the VESC Tool from the phone and from PC.

The PC version has more options but I do not see where the phase current here too. On the PC version of the VESC Tool when I try to set the battery current more than 60A it says "The following parameters were truncated because of they were set outside if their allowed limits"



Here are settings from the Current tab in the General menu. I do not see phase current setting here too

 

[chuyskywalker]

"motor current" == "phase current"

 

[TPEHAK]

OK, then the phase current is set to 100A.

I also found the Maximum Wattage setting in the VESC Tool application. But why does this setting exist if the voltage of the battery and the maximum current already determine the maximum wattage? Does this setting override and lower the current if it is lower than the wattage based on the maximum current? Does this setting affect something? Should I lift it if I want more power?

 

[scianiac]

Yes the wattage limit is just that, the motor current, battery current and wattage limit will each limit the power so whatever is the lower limit at a given operating regime will limit power. The motor phase current though is what is actually setting the power, if the throttle it set to current the throttle is controlling zero phase current to a max of whatever is set. If you raise the phase current then you may get a little more power in some areas even with the battery current fixed (like at low RPM), similarly raising the wattage limit may provide a little more power in some areas. Both of those may also be hard limited though.