1000W BMC testing

[oatnet]

Muad'dib, I thanked you on my build thread for that picture of the motor, but I'll thank you here again, great job!
I count 32 magnets and 36 stator poles.

I have someone that has tested this motor with a few different setups ... please check below..

Great chart Steveo, thanks!

Wierd results. On the 36v20a controller, both the 36v/48v no-load rpm is significantly higher than the 72v35a controller - wait, how were they getting 48v on a 36v controller?

On the 72v35a controller, both 36 and 48v are at @451rpm, but the 48v sucks a lot more current and generates a lot more heat. Do you know if the 36v was analog and the 72v was digital, and maybe the 72v was bumping up against its electrical rpm limit? With 16 pole pairs and 5:1 ratio giving 80 electrical RPM, 451 wheel rpm is 36,080 electric rpm.

-JD

 

[steveo]

Hey everyone,

Is there any motor on the market wound almost identical to the bmc motor that runs at cool temps like an x-lite motor ?

please post pics and motor type if you got em!

-steveo

 

[jag]

You can see for yourself how it is wound here:

Thanks for the picture. The magnets look very thin. Might they be rare earth magnets (like samarium cobalt or similar)?

I'm still wondering how much of an upgrade a BMC 1000W is over a BMC 600W. If it is just a lower wiring count, then one can just as well run the 600 at a higher voltage for better performance.

 

[jag]

I'm still wondering how much of an upgrade a BMC 1000W is over a BMC 600W. If it is just a lower wiring count, then one can just as well run the 600 at a higher voltage for better performance.

Here are the BMC 600W and 1000W pictures next to each other. Magnets and armature look the same. Slightly thicker wire gauge in 1000W.
So it looks like BMC 600W should have as much power potential as the 1000W labeled one. Just need a bit more voltage.
Pics are from Shinyball's and Muad'dib's motors.

 

[nicobie]

I think the freewheel/gear assembly is different on the 1000w. Ilia told me that it is directly bolted to the magnet cup. It is supposed to be more robust.

 

[dirtdad]

The V3 motor also has an upgraded clutch.

 

[oatnet]

I didn't realize the freewheel/clutch were upgraded. I was thinking about seeing how the 600w works at 72v, as the small Kelly for the BMC V3 really didn't like anything over 48v, and with unlimited amps it only seemed to go 30mph with my typical upright riding position.

I've given up on my hope of overvolting the V3 to make a sick drag bike. Instead I am going for a lightweight stealthy bike, so I'm currently working on a 15s3p a123 pack that will sit under the frame, between the pedals.

-JD

 

[dirtdad]

I had similar results with the Kelly/V3 at high voltage.

The Infineon 72V gave better results than the Kelly. My V2S with the 72V 65A infineon was good for a little over 40mph. I did a shootout with it vs the Clyte 5304 with the same controller. The Clyte edged it out slightly every which way, but only by a few mph. The V2S descended better by virtue of the freewheel and felt more like a bike given the weight. But it also heated up the phase wires a lot on big climbs (1 mile climb peaking at 15%), but the controller never failed or went into thermal cutout.

 

[jag]

I had similar results with the Kelly/V3 at high voltage.

So summary of current state of V3 would be:
1. Slightly stronger mechanics than V2. Otherwise power potential same as V2. However except for shinyballs I never heard of someone whose V2 broke mechanically.

2. Nobody found a controller that works real well. I was curious if anyone tried Methods 100V 100+A special build controller?

It is also puzzling how the BMC 1000W can be harder on the controller than the low winding count Clyte 5302 and 5303.

The Infineon 72V gave better results than the Kelly. My V2S with the 72V 65A infineon was good for a little over 40mph. I did a shootout with it vs the Clyte 5304 with the same controller. The Clyte edged it out slightly every which way, but only by a few mph. The V2S descended better by virtue of the freewheel and felt more like a bike given the weight. But it also heated up the phase wires a lot on big climbs (1 mile climb peaking at 15%), but the controller never failed or went into thermal cutout.

Maybe one can reason as follows:
BMC has 4:1 gearing,
but Crystalyte has bigger diam motor and wider magnets.
If motor is 2x diam and magnets 2x wider, then that gives a raw motor torque advantage on par with BMC's gearing.
Obviously nice to have the low weight of the BMC, but no power torque advantage.

 

[jag]

I've given up on my hope of overvolting the V3 to make a sick drag bike. Instead I am going for a lightweight stealthy bike, so I'm currently working on a 15s3p a123 pack that will sit under the frame, between the pedals.

I was also eyeing the V3 for a lightweight, stealthy bike, built on a Specialized FSR frame.
However don't want something that would go slower than my current Stumpjumper + 9C@72V.
I think I'll be holding off until the V3 controller issue is figured out. Or I'll get a V2.

 

[dirtdad]

One more data point. I had the V3 wired up to the big 18 FET infineon and batts capable of 72V 65A peak. The motor charged to 40mph strong at just partial throttle with a lot of head room left. But the big infineon kept throwing its thermal protection at that point, and I felt I was pushing the batteries pretty hard, so I never got past 40mph. But my gut feel is we are talking a top speed in the upper 40s anyway. There is great potential in the motor with the right controller. But that controller just does not seem to exist yet.

BMC promises a 50A controller, but I am sure it will max out at 48V.

 

[nicobie]

hey jag,

I wasted the clutch on a v2 600w hub motor that had a v3 clutch in it. However I feel it was due to the crap throttle response I was getting from Keywins infineon controllers (I tried two of them with numerous throttles). Everything is fine now that I'm using a 72v clyte analog controller. I'm using 76v/20ah batteries and the controller stays cool to the touch even on long steep hills. The hub motor housing never seems to get over 115*f. I've upgraded the phase wires to 12g up to the axle and they only get a little warm. Top speed is 39mph on the flats with no pedaling. I've got a 52t ring gear with a 11t small gear on the rear cluster and can't really spin fast enough to add anything when going flat out. I am thinking about getting a bigger chain ring like zoot did. Then I'll bet I can hit 40mph.

 

[disndat]

Hey heres a thought-has anyone tried modding a bmc controller to do 72 volts 50 amps?I mean if we can mod xlyte controllers and such -why couldnt we mod the bmcs?

 

[dirtdad]

Good point. The BMC controllers have 12 4110 fets, they should be able to do 50A. BMC will provide a resistor to put in line with the shunts to allow 35A peak. A little solder mod could bump the amp limit higher. BMC made it clear that even at 35A the controller is not warrantied, so at 50A you would definitely be on your own.

 

[disndat]

If anyone wants to donate a bmc controller.I will get steveo to mod it and test it with my 1000w bmc

 

[itselectric]

Steveo had posted our BMC and controller test result back in Sept, we were unable to complete it due to time/resources and missing hardware until now. We want to create a comprehensive chart to determine which combination works the best, what is the raw performance of each setup. After we have collected the test result, we also take it out for real life testing to make sure the lap test truly reflecting the real life. We will make a video later for comprasion of each setup, and post it in this forum. What you see here in this chart is smaller subset only focusing around BMC combination, we will continue to collect more motor and controller for our test result.

View attachment Motor paired Controller RPM Testing.pdf
We cleanup the result set to make easier to read. Here are some of the high light of the result:

1.) the BMC 1000w works best with Crystalyte 40amp analog controller had the highest rpm at 668. When combine 1000w motor with digital controller, it create an extremely high heat at the phase wire. It raised up to 96 degree Celsius (70 degree ambient temperature) in one minutes. Imagine when you running it for 10 minutes. In this chart, the BMC 1000w (668rpm) at 48v with the right controller will out performance 5304 (498 rpm, we still need to verify in real life test).
2.) The BMC 600 V2S work well in both digital and analog controller, however, by using the analog controller will have a bit more higher RPM
3.) The Infineon controller loaner from comcycle USA also works well with BMC 1000w, it has a bit lower RPM then the Crystalyte analog controller
4.) The Amp doesn’t change the top speed much

The reason why some of Crysalyte analog controller were 35amp and other at 40amp in the test result, is because before we can finishing the test, someone had seen the result, purchased all of the 40amp analog controller. So now we only have 35amp controller in stock. The BMC 600w V2T is not completed yet, we are just waiting for the motor to arrive.

I welcome everyone input, if you have suggestion what measurement that I should included to improve the interpretation of the result, we can added it to our next test cycle. Unfortunately, we do not have the equipment to include the torque test at this time. We will come up with a new setup later.

Ken

 

[Jerome Daoust]

Thank for doing doing that testing and sharing Ken. Well done!

- the other JD

 

[oatnet]

Thanks for the results! I see you got 666 rpm on an xlyte 36v35a controller, but it reports that you tested at 48v. Was the 36v controller able to handle the 58v of a nominal 48v pack?

-JD

 

[itselectric]

Thanks for everyone appreciation! It takes a lot of preparation to do this kind of work. I have two people working part-time on this. Whenever we can find the time to do this. It is also hard to reserve the hardware to do the test.

JD:
Almost all xlyte 36v controller come with 63v cap, you can easily run with 48v without any problem.

I would like to point a few things during our testing. We place a temperature probe inside the axle onto the phase wire, so we can get a much faster temperature re-action, so we can stop the test on time before going into melt down, burn out either motor or controller.

You can also see the BMC 1000W actually generated a 1000w load during an overload phase wire heating.

Based on the current result, I am interpreting that the gearless hub motor are more efficient for long distance range. It consume very little amp. Between 1.1amp with 408 motor to 1.9 amp 5304 motor, almost no heat at the phase wire. Where a gear motor will provide much better torque, this test result doesn’t show it. But It consumes much higher amp between 3 to 6 amp. The higher amp consumption will translate to shorter-range compare to gearless motor.

We are going to take each configuration out for real life testing, but last time I check, I believe BMC V2S may have run a bit more faster then BMC 1000w, don’t quote me on this yet. I need to have proper setup in order to produce good result.

Overall, this testing really opens my perspective how I look at each component. You can’t just stick a controller into mix and expecting everything will just work, and you need look beyond the manufacturer spec, it needs to be proven, otherwise they are just number.

Ken

 

[Jerome Daoust]

Hi Ken,
Do you have access to the 50 A controller that is discussed here?
Great news for BMC 1000W owners

It would be great to se how it compares to the others you have tested.

 

[itselectric]

Hi Ken,
Do you have access to the 50 A controller that is discussed here?
Great news for BMC 1000W owners

It would be great to se how it compares to the others you have tested.

Jerome:
I contacted BMC the date the message was posted. I haven't got any reply. Be aware the top speed or RPM will not change much by having 50A. In that video, the battery pack was a 60v not a 48v, as a result it pass 40mph mark not because it was a better controller. I will include the BMC 50A controller as part of the test result, once I able to get it in my hand.

There are a few more test that I like to do, for example:

- run the 48v battery pack with the 1000w for longer run time with median load to see if other thing heat up such phase, motor, or controller
- run the same test at 72v. Actually, this is hard to do, because the top speed will be around 60+mph, i will need runway to do this
- run a real life test to check top speed at 48v
- run a real life test to check top speed at 72v
- run a real life test at 48v at slope without pedaling, we have see this burn out with crystalyte digital controller
- run a real life test at 72v at slope without pedaling

Again, I would like to hear if any other suggestion what to test, to determine the best configuration for the best performance.

Ken

 

[Jerome Daoust]

Thank you Ken,
I'm impressed by your methodical testing and dedication.
I get the feeling you are looking out for the consumer.

- Jerome

 

[mjttlt]

I thought I would use up my first post to thank you for this testing. This is the most valuable information I have been able to locate. It will really help me decide what will suit me best for the application I choose. I can't thank you enough.

 

[Whiplash]

So, are these problems solved officially? I am seriously considering this motor for my prototype...

 

[tycreek]

I thought I would use up my first post to thank you for this testing. This is the most valuable information I have been able to locate. It will really help me decide what will suit me best for the application I choose. I can't thank you enough.

So, are these problems solved officially? I am seriously considering this motor for my prototype...

Be careful when digging ... Note dates ... keep an open mind ... I know there might not be much information ... especially anything definitive about a best V3 combination ... I read this back then and was trying all the tid-bits of information I could find out ... determined to make my V3 work at all speeds and points along the throttle band... To me there's much more that I want from a controller than just top speed. Yes, it is one of the factors to consider. But please do take note of what all those people still running the V3 finally ended up using on their rides. Or what they would choose now if given a choice to do it over.

Anyway... I've used both the Clyte's, a Kelly and the more recent than those tests BMC 50A. The BMC 50A gave me the best "usable" response and all around behavior by far! The Kelly was good too ... but I picked the BMC to keep and use. I then tried Ilia's modified BMC 50A that is controlled by a Direct plug in CA and it really rocks! IMHO ... and little bit of experience... Ilia provides the best combination for the V3 of anybody on the planet at this time. WHY? well the BMC 50A controller is TOO much for the V3 - you will melt wires etc... if you simply open up the throttle and hold it and ebikessf is the only place I know of that you can purchase a way to make the combination "right".

So, if you go V3 watch your CA closely or do some sort of mod to limit current to safe levels (remember it is designed as a 1000w motor NOT 2.5k). Soft start is good if you're one who pulls full throttle all the time from a start. I used soft start and speed limit for a long time. The speed limit only limits speed and NOT current so it really is of no use in protecting the motor. The soft start puts a delay into the throttle response that for most riding doesn't matter much but when getting technical and riding on the edge so to speak... I like to have the power control in my own hands precisely when and where I turn the throttle. I ordered some small dip switches to put on the wire ends instead of the connectors for easy jumper selections as needed.

I think the BMC rocks in it's hub type space! So much so... once I got it dialed in I started on my second bike based on those results. Others run other ebike drive systems RC or hub and some are really killer setups for one reason or another. I've not ridden a hub that works as good as mine at 36v or my favorite 48v. All that are really efficient that I know of are gutless and those that lift the front wheel are usually RC and noisy or run very high voltages and are being fixed more than ridden.