ME1507 vs QS motors

K1w1

1 µW
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Jan 3, 2021
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Hi all. I'm in the planning stage of an E-bike. The plan is to race flat track on it, which to me is ideal for electric. My typical race day will include < 30 minutes riding total, with about 10 minutes spent on the throttle across all races. So range is not so much of a concern, so I should be able to pull a large current out of the pack as it's never running long enough to generate a lot of heat.

Initial plan is something like 72V and circa 450A peak draw. Perhaps a 20S22P 18650 pack with 20A cells, dependent on motor / controller selection. Torque when I get on full throttle is more important than top speed on the short tracks I'll be on.

I may have access to a very reasonably priced ME1507 and Sevcon Gen4 size 6 (although at the price I could pay I would likely sell the Sevcon to fund a controller without expensive software). And on paper this seems like a good option, but this forum seems to suggest the Motoenergys underperform to specs. What I have also seen is a decent amount of praise for how hard QS motors can be pushed. The QS 138 seems like it could be run with the same voltage / current, but can it reliably be pushed to 30kW +? The much smaller package size than the ME1507 would be a big advantage when using a standard MX frame.

Then there is the 273, in this application added wheel mass may give an advantage in traction, so running a hub motor is not necessarily a bad thing, and it seems like I could get more performance out of the 273 than the 138, so this could be an even better option?

Have any here experience with all for a comparison? Would I have to run much higher voltage on the QS motors to reach the same output due to current limitations?
 
Though the ME1507 performs below spec it is still a very good motor. I also have great personal praise of QS's 138 motors but you're trying to compare two very different motors, they're very differently shaped and in different weight classes, the QS mid drives are smaller in diameter but a lot wider and weigh 11/14kg depending on 70H or 90H while an ME1507 weighs 20kg?

I think a QS 138 70H can push 15-20kW, somebody can correct me if I'm mistaken. So maybe a 90H can do 25kW? Maybe more?

An ME1507 will safely do 35kW maybe 40kW at the wheel, I know people have dumped as much as 50kW from the controller/battery into this motor but it isn't very efficient so 35kW-40kW is a safe bet for real word performance. Highest dyno of a Motenergy I've seen was 40kW and it was an ME1616.

Real world power at the wheels is a lot different to how much power the battery is pushing or the controller is dumping into the motor and people ignore this. It is possible that people are throwing as much as 30kW into a QS 90H however it doesn't mean it's putting that down which is the issue with Motenergy.

The 1507 is advertised as a 50kW motor yet I've yet to see anybody actually have that power in the real world.

Secondly to maximise either motors potential you're going to want to run a lot higher than 20S, if I'm correct Motenergy recommends 28S for their 1507 and people seem to be having very good results pushing the QS 138s to higher voltages such as 26S.

Torque is something you will deal with depending on the gearing & controller you use.

If you buy an IXXAT (for the Sevcon) they will give you access to the software for free, they will get your software activated by Borg warner but as everybody says, programming a Sevcon is a lot more difficult compared to other controllers but the potential is much greater regarding acceleration.
 
I've got no observations on the QS mid-mount motors, but I wouldn't want to flat-track a hub motor unless the suspension was well dialed in. The ME's are pretty good for the price, and probably appropriate for the power you need.
 
This is pretty much bang on the reply I wanted to see. Had been set on the ME but the QS seemed to be a curveball. I'll continue down ME route provided I can get hold of it.

72V was mostly selected due to controller availability, having spoken to John at ME in the past he recommended 72 and 100V as preferences for the 1507. I certainly don't need 50kW out of it.

Acceleration and regen are both pretty key, so Sevcon is certainly the natural choice and the 80V I can get hold of seems like it could handle running at 28S. I'm not sure what other options there are; kelly kls96601 - apparently slow initial acceleration, mobipus impossible to get hold of ...
 
Very interesting :thumb:
I will try not to hijack too much.

From what it says on ME:s site ME1507 and 1616 is the same motor, only water or air cooled.
Then they should be capable of the same output, but maybe not for the same time.
Is that not the case?

I think there is a thread here with a go cart with me 1616 and sevcon size 6.
I think he was struggling to get over about 20kw output.

I run a qs 138 70h myself, with up to about 30kw in to the motor. I dont know the output though.
I havent seen those running higher voltages, are they on this site?

There are the qs 180 90h motor too, it seems like they are more or less ready to start selling it :wink:

I looked at golden motor, their 10kw version. One thing that looks interesting is double phase wires. It seems like you can split and run dual controllers. But it seems like it overheats if you push it.

Both the qs motors and me1507/1616 is ipm, so a controller that can do mtpa would be very nice. It is not easy to find the right motor, but it seems to be even harder to find the right controller.
 
What I've been told by John is the 1616 can push 80% higher continuous current. I guess upper limits are about the same.

Your bike j bjork was definitely one of the ones that got me thinking about the QS motors, I can't seem to find any info on the 180 90H if you could point in the right direction?

Definitely harder to find the right controller! Might have to bite the bullet and go sevcon it seems
 
I dont think there are much info available about the 180 motors, but you can find some around page 50 in the qs sales thread.

Threads like this makes me doubt sevcon:
https://endless-sphere.com/forums/viewtopic.php?f=30&t=109180

Interesting about golden motor:
https://endless-sphere.com/forums/viewtopic.php?f=30&t=63071
 
j bjork said:
Threads like this makes me doubt sevcon:
https://endless-sphere.com/forums/viewtopic.php?f=30&t=109180

I honestly think it's his settings rather than the Sevcon itself

Another person here on Endless has a go kart build and used Goldenmotor, Motenergy ME1304 then a Zero 75-7.

https://www.youtube.com/watch?v=olb96Gf0KlY

Even the performance of the ME1304 and Golden motor wern't that bad considering they were drawing about 30kW.

He now uses a modified 75-7 that has better cooling and achieved a sub 3s 0-60.

So no, the Sevcon isn't a bad controller, arguably one of the best if you know how to use it correctly.
 

@j bjork: wonder if the bac8000 might do look-up table field weakening. haven't seen any program screens here on ES yet.. might be worth checking

VESC guys seems to be working on mtpa https://github.com/vedderb/bldc/pull/91
 
c70r said:
Another person here on Endless has a go kart build and used Goldenmotor, Motenergy ME1304 then a Zero 75-7.

Nice, is there a build thread?

Something that bothered me in the thread I linked to was that (from what I remember) the guy from ME thought the power was what to be expected.
But you are right, many seem to get good power out of sevcons.
 
larsb said:

@j bjork: wonder if the bac8000 might do look-up table field weakening. haven't seen any program screens here on ES yet.. might be worth checking

VESC guys seems to be working on mtpa https://github.com/vedderb/bldc/pull/91

Bartosh is testing the bac8000, but it dosent seem to encouraging so far.

I thought Vesc had mtpa now? (From the Axiom team)
 
larsb said:
Correct, seems that MTPA was introduced in VESC:
https://hackaday.io/project/164932-axiom-100kw-motor-controller/log/179447-mtpa-merged-into-vesc
Then i guess next step is to get an axiom :D

It has been a while since I read the axiom thread, but from what I remember it is high voltage and price. But not very high amps?
So probably not what I am after. It would be possible to go with an emrax motor and 400v, but I rather not I think..

c70r said:
Another person here on Endless has a go kart build and used Goldenmotor, Motenergy ME1304 then a Zero 75-7.

https://www.youtube.com/watch?v=olb96Gf0KlY

Even the performance of the ME1304 and Golden motor wern't that bad considering they were drawing about 30kW.

He now uses a modified 75-7 that has better cooling and achieved a sub 3s 0-60.

So no, the Sevcon isn't a bad controller, arguably one of the best if you know how to use it correctly.

I found it, it was nuxland as I suspected. I didnt remember he had used those motors.

https://endless-sphere.com/forums/viewtopic.php?f=34&t=68543&start=75

Interesting thread, and dyno on page 4.
 
That 75-7 & sevcon combination is nice, 50kW
Truly expensive stuff though.

If the apt961000 would be known here, combined with QS138 90H or one of the unobtainable larger QS mid motors.. if i’d been looking for a new build then i’d try that.
 
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