Motors Maximum Voltage and Amps

cwah

100 MW
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Between paris and london
Hello guys,

At present I start to have a hand on several motors, I'll put a thread here on some on the motor maximum I've managed to get before it starts to be unusable.

Mac geared:
Maximum voltage: 80V. Clutch start to have problem on start on max power.
Optimal voltage: 60V. Max voltage for efficient start
Optimal amps: 35A. No issues so far


BPM geared:
Maximum voltage: 80V. Clutch start to have problem on start on max power.
Optimal amps: 35A. No issues so far

Cute100H:
Maximum voltage 48V (12s). Motor becomes inefficient when voltage gets higher. Like 200W usage at no load.
Optimal amps: 15A.


Leaf bike 90% DD motor:
Max amp so far: 35A. I'm going to change it soon to put 65A on it.



I'm thinking to maybe test higher amps on the BPM. Something like 65A. I'd just use it for peak acceleration, like starting from a red light for 10second or so. Would the gears/clutch manage that?
 
Interested in seeing how the Leaf does.
 
why does a MAC geared have only 80V as max ? What happens then ? I cannot imagine the isolation of the windings not being up to the task....?
Torque and clutch issues are related to the current, not the voltage ?
 
Lebowski said:
why does a MAC geared have only 80V as max ? What happens then ? I cannot imagine the isolation of the windings not being up to the task....?
Torque and clutch issues are related to the current, not the voltage ?
Exactly, a motor has a limit that is a relation "watt vs time"
It can stand so many watts for so much time, that is much more useful data than continuous power rating for those who are into performance :wink:
 
Well what winding is the Mac at? I don't think a 12T Mac should have problem at 80V. Maybe I am wrong, but I would love to hear what others who have tested say.
 
cwah said:
Cute100H:
Maximum voltage 48V (12s). Motor becomes inefficient when voltage gets higher. Like 200W usage at no load.
Optimal amps: 15A.

Wow, this is very interesting data on Q100H! I'm using Q100H 36V 201 rpm, oil cooled with 100ml ATF at 13s (54.6V hot of the charger) . My values are:
P_in=175W DC (battery) usage at 32km/h (3.5A at 50V, 26"x2.25"MTB wheel, m=100kg(83kg+17kg), flat terrain). That gives about P_out=131W at 75% efficiency (controller+motor). How do you measure no-load usage?
 
Lebowski said:
why does a MAC geared have only 80V as max ? What happens then ? I cannot imagine the isolation of the windings not being up to the task....?
Torque and clutch issues are related to the current, not the voltage ?

What happen is that the clutch slips on starts. I have to be very careful and start very slowly and cruise around 5-10mph before I can pump 35A (2.8KW) to the motor.
 
mvly said:
Well what winding is the Mac at? I don't think a 12T Mac should have problem at 80V. Maybe I am wrong, but I would love to hear what others who have tested say.

It doesn't have special issue once the motor is running of 10mph. It's just hard start that can kill the clutch.

It's with a Mac 8T and a bpm v2 328RPM model. They both have exactly the same issue. I don't know for the mac 12T but I wouldn't be surprised if to see the same issue
 
but killing the clutch, this would have to do with the torque the motor delivers. Which has nothing to do with the voltage but with the phase currents through the motor (and the controllers ability to control these currents)
 
fellow said:
Wow, this is very interesting data on Q100H! I'm using Q100H 36V 201 rpm, oil cooled with 100ml ATF at 13s (54.6V hot of the charger) . My values are:
P_in=175W DC (battery) usage at 32km/h (3.5A at 50V, 26"x2.25"MTB wheel, m=100kg(83kg+17kg), flat terrain). That gives about P_out=131W at 75% efficiency (controller+motor). How do you measure no-load usage?

No load usage was just spinning the wheel (26") with an adjustable power supply and see from a wattmeter the amount of amps pulled from the power supply.

Initially I tried the motor on an 80V battery thinking I'd have the same small clutch issue on start. But then I realised that the motor was impossible to control.

So I tested the motor at various voltage until I found out the point of saturation :)
 
Lebowski said:
but killing the clutch, this would have to do with the torque the motor delivers. Which has nothing to do with the voltage but with the phase currents through the motor (and the controllers ability to control these currents)

The things is for the same current (35A), it works perfectly fine at 60V and clutch starts to slip at 80V.
On a smaller motor, increasing voltage makes the motor can make the motor extremely inefficient to the point it prevents motor to start (see the cute100H)

So keeping the same current but increasing voltage has a limit with any geared motor.
 
cwah said:
Lebowski said:
but killing the clutch, this would have to do with the torque the motor delivers. Which has nothing to do with the voltage but with the phase currents through the motor (and the controllers ability to control these currents)

The things is for the same current (35A), it works perfectly fine at 60V and clutch starts to slip at 80V.
On a smaller motor, increasing voltage just prevent motor to start (see the cute100H)

So keeping the same current but increasing voltage has a limit with any geared motor.

But what kind of controller is it ? Typically a controller has a phase current and a battery current limit. At a certain rpm, the 35A60V will start
limiting the phase current not to exceed the battery current, while at 35A80V it will not yet limit the phase current as the battery current is below 35A.
 
On the mac I tested it on Lyen and Cellman 37-72V 12Fet 35A controllers

I played a bit with phase current to see if I can prevent the clutch slipping issue and unless I put a ridiculously low current (like 10-15A), I'd still have this issue.

So I gave up on that and just decided to do manual soft start and enjoy a better max speed.

Now I'm using greentime controllers and I have the same issue
 
cwah said:
So keeping the same current but increasing voltage has a limit with any geared motor.

If you increase voltage keeping the same Amp settings, you are feeding more watts.
It is not exceeding voltage that is killing your motor, it is feeding it above its power limit.
 
Sounds like you would do well with something like a Throttle Tamer and some configuration of current.
 
cwah said:
...just spinning the wheel (26") with an adjustable power supply and see from a wattmeter the amount of amps pulled from the power supply.
I've measured the wheel in the air current of Q100H today, it was 1.0A at 54V, full throttle (P_in=54W). It's ATF oil colled (100ml), maybe the values are that good because of oil inside?
 
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