Max peak power for QS 205

patrik5504

1 mW
Joined
May 21, 2022
Messages
13
Hello, I'm looking for personal experience, who has a qs 205 v3 motor, preferably 40x3T, what peak power can this motor handle? I've seen a couple of videos where people put more than 300A into the motor, so I'm asking, how many amperes can it handle so that it's still effective?
I have a 72V 430A controller and a battery that can deliver 72V 400A peak power for a few seconds
How much can I let go so as not to hurt him?
 
Regarding current: do you want Phase amps, or battery amps?

Regarding peak power (different from current), how long do you need it to handle this peak wattage for?

patrik5504 said:
Hello, I'm looking for personal experience, who has a qs 205 v3 motor, preferably 40x3T, what peak power can this motor handle? I've seen a couple of videos where people put more than 300A into the motor, so I'm asking, how many amperes can it handle so that it's still effective?
I have a 72V 430A controller and a battery that can deliver 72V 400A peak power for a few seconds
How much can I let go so as not to hurt him?
 
Controller rated DC 430A, phase 800A, battery 72V40Ah, continuos 200A, peak max 400A
I want to know how many amp of current from the battery I can put on this motor for 5-10 seconds so that it does not burn out.
just how much load can this motor handle and will it make a difference if I put 200A or 300A on it.
sorry if I still don't understand what exactly is needed.
 
patrik5504 said:
Controller rated DC 430A, phase 800A, battery 72V40Ah, continuos 200A, peak max 400A
I want to know how many amp of current from the battery I can put on this motor for 5-10 seconds so that it does not burn out.
just how much load can this motor handle and will it make a difference if I put 200A or 300A on it.
sorry if I still don't understand what exactly is needed.

Are you pulling a trailer? It would be hard to pull that much for more than a split second, unless you have a big load.
 
patrik5504 said:
Controller rated DC 430A, phase 800A, battery 72V40Ah, continuos 200A, peak max 400A
I want to know how many amp of current from the battery I can put on this motor for 5-10 seconds so that it does not burn out.
just how much load can this motor handle and will it make a difference if I put 200A or 300A on it.
sorry if I still don't understand what exactly is needed.

How many amps will depend partly on how it's being used. If you put a huge load on a motor at a low (or zero) RPM, and allow a lot of current, it can quickly overheat, but the same current allocation at high RPM may be perfectly fine. You can see how some of this works by playing with the various existing setups on http://ebikes.ca/tools/simulator.html if you are willing to spend some time at it (and read the full page of instructions below the chart/graph/etc that explain how to use it).



Perhaps you should state exactly what you want to use the system for, under what specific conditions, with what kind of riding style. That may help us help you find the right parts to build the system that will do the work required to get the job done.

Starting from the other end like you're doing doesn't always get the desired result, but starting from the requirements end and then getting everything you need to do that job almost always does. ;)
 
Okey, thank you. So I'll start, it can't be returned, I've already ordered the controller and the battery. I have also already ordered a ebike frame with a mid-drive, where I can put a qs 205 motor. I haven't ordered the motor yet. Even before buying the motor, I would like to know how much power I can put into the motor.
Purely theoretically, if I set the controller to 350A, when starting from a place, the controller would put to the motor 350A and the current would gradually decrease until as reached a highest speed?
I don't have much choice, but I will take the qs 205 as mid-drive or put the motor in the rear wheel, for example the qs 273.
I would like to know how the motor will behave with this configuration.
 
The current will remain as high as it needs to be to provide the motor with the power to overcome whatever load you put on it.

So to know what the motor will draw from the controller, you would need to know what load will be on it, which means knowing the usage scenario and conditions. How much power can be put into the motor also depends on it's usage; as noted before.

I recommend you go to http://ebikes.ca/tools/simulator and play with the existing setup to see how this works.

As for what the QS205-50H can take, I have one here I bought used with both axles broken off, and shredded external cable, that was used at something over 11,000watts before it failed. But the motor itself, it's windings, halls, etc., are intact. I don't know what voltage or current it was used at for that wattage, however.

Other versions of the QS205 (different "H" numbers) may not be the same capabilities; QSmotors should have specifics on their limitations.

patrik5504 said:
Okey, thank you. So I'll start, it can't be returned, I've already ordered the controller and the battery. I have also already ordered a ebike frame with a mid-drive, where I can put a qs 205 motor. I haven't ordered the motor yet. Even before buying the motor, I would like to know how much power I can put into the motor.
Purely theoretically, if I set the controller to 350A, when starting from a place, the controller would put to the motor 350A and the current would gradually decrease until as reached a highest speed?
I don't have much choice, but I will take the qs 205 as mid-drive or put the motor in the rear wheel, for example the qs 273.
I would like to know how the motor will behave with this configuration.
 
I did a simulation, I tried to do it right, I use the motor MXUS 4503 (it should be a qs 205 3t motor), middrive, motor sprocket 27t, wheel 35t, gear ratio 1.30:1,, 72V battery, 400A controller with 800A phase, approximately with tire 24' wheel, 150kg weight , full throttle.
The maximum speed is approximately 100 km/h, I heard that the speed can also be increased with the weakening of the field.

Electrical Syst A
Mtr Amps 237.2A
Batt Power 5884W
Batt Amps 234.6A
Batt Volts 25.1V

Am I to understand that the motor does not go more than 240A and is there a limit?


https://ebikes.ca/tools/simulator.html?batt=cust_72_0.2_40&cont=cust_400_800_0.03_V&wheel=24i&mass=150&hp=0&throt=100&motor=MX4503&mid=true&tr=27&tf=35&gear=&gear=1.30
 
I'm running a few Nucular 24f controllers on QS205s 3T and 4T @ 350ba and 500pa @84v 88v and 92v no problems
all run at 20kw.
I did run qs205 @ 124v on a APT AE96600......now that was fun :shock:

Jonno
 
Jonno said:
I'm running a few Nucular 24f controllers on QS205s 3T and 4T @ 350ba and 500pa @84v 88v and 92v no problems
all run at 20kw.
I did run qs205 @ 124v on a APT AE96600......now that was fun :shock:

Jonno

Thank you for info, that sounds very good, what is your max speed at 92V? Nucular 24f isn't the controller limited to 300A?
 
patrik5504 said:
I did a simulation, I tried to do it right, I use the motor MXUS 4503 (it should be a qs 205 3t motor),

Wrong motor...... use the Cromotor 5004 ( click " SHOW ALL"). Set your own kV, set the throttle choice to torque, and set human power to 0.

MXUS is a 45mm mag. You want 50mm mag. Also, on the custom battery, you have it as 200mOh. That is high in my opinion. Mine is 25mOh ( lipo). I have 20 cells, ea is 1mOh. Plus bus bar and contact resistance. Even a junk 18650 pack is better than 200mOh.

1/5 ( 200/1000.. "200 milliohms" ) of an ohm is alot. Mine for example is 25/1000 of an ohm..( or 1/40 of an ohm .. " 25 milliohms").

A 200mOh battery would be saggy and laggy. Max output would be compromised ( sag under full load) .


QS 4T is ~13kV, you have the sim set on 13kV. you need to correct this to get a real representation of a QS3T.

~3T is 16kV. I think. IDK. I do know the 4T is what you have the sim set for. A QS 3T is higher than 13kV.

I have peaked 18,000watts trying really hard with a 4T on a 350A controller. 134lb bike. Pulled 280A max and that was all the load I had at that kV choice. Topped out at 55mph. It was really fast, like 4 sec to 40mph.

Continuous is a whole different story. I pull 4kW continuous for 50mph.
 
Here I changed a few things for ya.

I changed:

From the MXUS ----- to the 5004 Cromotor ( QS205 is a clone of this motor) ....
From your set kv ( 13kV) ----- to the real kV of a QS 3T 205 motor ( 16kv)
From your set battery resistance from 200mOh---- to 20 mOh...
From your " Voltage control throttle " to " Torque control throttle" ( so you can have more fun playing around with the throttle slider to see how (th) demand affects the ( motoring) efficiency) ( noone rides at 100% the entire life, except Valentino Rossi) ...

You can change the grade % ( SLOPE), and simulate, to figure how much, hills in your area, would affect the setup(s) effective efficiency. ( Trust me, it will laugh at any hills you can find.. with those specs...and that much torque... )....


See how much throttle you would need, ( how much you turn the throttle) to go (x) fast, or up (y % ) hills.


This is the output.
.....battery power peaks at 25,565W ( 399.2A) upon full demand acceleration to final velocity. Motor power peaks at ~9000w @ 380 motor amps, at 50 kph, and the maximum phase amps off the line ( from 0 kph) will be in the region of (612A) off the start when under full demand. Final velocity is 90.2 kph.

Good luck with that. A helluvalotta tork with that ration. You max out at 26.83 km/hr/sec. ( that is very fast) on takeoff and it slows the acceleration from there to a final velocity of 90km/Hr. I think you dont need such an extreme ration. It will just wheelie whenever you really try to get on it, if you hit it from 50km/hr or less and demand full throttle. Yeah its got the tork to wheelie. Well over 200nM anywhere under 50km/hr,... upwards (a peak) of 360nM off the line from 0 RPM... . I dont know, though. It looks like a hell of a setup, a 50H magnet motor used as a mid drive on that gearing and voltage. Even riding at 25% throttle, you have a great amount of tork....100nM. Load is not great ( alot of load) and that means it will MOVE. Setup certainly overpowers its final speed ( motor power drops with final velocity) ( reaching back emf, current drops..)( less load, no demand, motor can not go any faster, no horsepower needed to accelerate, less tork is used), (takes power to spin it up, but does not take power to hold it spinning)... to somewhere around 6000w.. batt power to ~8000w... @ full speed) ( Even at 25% throttle demand you will be accelerating to final at a peak of 8km/hr/sec. )( Which is fast enough to get around certainly, only using 1/4 throttle..)


The controller specification you provide is very powerful. IF you can supply a very powerful battery. The motor will get VERY hot with those numbers. You would want to keep the full throttle load events down to a minimum, at least, less than 16% of the time, or else you will risk overheating and damage. Aside from that full throttle acceleration, all day long.... ... The motor should handle it. Motoring load is not that great. Acceleration load is great. As long as you do not drag race every throttle application.... do not try to beat the world record every day... The motor can handle it. However, if drag race, and drag race only, the motor will overheat.

https://ebikes.ca/tools/simulator.html?batt=cust_72_0.02_40&cont=cust_400_800_0.03_T&wheel=24i&mass=150&hp=0&throt=100&motor=MCRO5004&mid=true&tr=27&tf=35&gear=&gear=1.30&kv=16
 
DogDipstick thanks for the extensive explanation, I really appreciate it. I learned something new again.
I'll use full power occasionally when I'm overtaking or having a little fun. Of course, I don't want to trouble the motor too much and constantly go full speed, I saw that it can overheat quickly. I would be interested, the graph shows a speed of 130 km/h, which I think is nonsense. I know that higher speed can be obtained with a weakened field, are there any disadvantages?
 
patrik5504 said:
would be interested, the graph shows a speed of 130 km/h, which I think is nonsense. I know that higher speed can be obtained with a weakened field, are there any disadvantages?

The graph shows a top speed of 90.2kph. The information below the simulator will tell you how to interpret the results.
 
999zip999 said:
O.k. when you get this together I want to see your very first ride on video or it didn't happen.

well, in about 1-2 months, all the parts should arrive, so I'll post a video here. I can only wait for now.
 
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