Leaf / leafmotor / leafbike high efficiency 1500w motor

I did ask them for 4T in the comment field and in the mail conversation.
With my mxus 4t I could only get 75km/h on 20s and this thing does over 80km/h on 18s.

Got update from Leaf:
"Yours is 4T.
If 3T is faster than yours.

Yes,work our 40A LCD controller,max speed is 72kmh No load.(Our LCD limit max 72kmh,can’t over 72,but if use other controller,it will over 72kmh)"
 
Allex said:
I did ask them for 4T in the comment field and in the mail conversation.
With my mxus 4t I could only get 75km/h on 20s and this thing does over 80km/h on 18s.
Click to expand...

MXUS has a wider stator, and a wider stator means a lower kV for the same turn count.
On condition that both motors have same stator design and pole count, magnet strength etc.

if you compare the 45mm mxus with the 35mm leaf, the mxus has 28% wider stator so the Leaf should have 28% higher kV
therefore about 12kV for the 4T.
 
Hi Cowardlyduck,

Just wanted to say that I don't mean to imply anything negative about your build. This is where I'm coming from...

I believe (correct me if I'm wrong) that no-load max rpm is a characteristic of a motor. It should be very similar between motors of the same make (and condition).

Also, we have a pretty good handle on the 1500 watt Leaf (~13.1kV for 4T and ~10.2kV for 5T). If you flip your bike over and run up to max rpm you should expect Vx10.2 rpm for the 5T motor (or Vx13.1 rpm for a 4T). If its very different than that, I'd wonder why.

Comparing bike speeds (kph under load) or different motor types introduces too many variables to make meaningful comparisons (for me, anyway). That's where the sim comes in (thanks to Tek for bringing that into the conversation).

A couple suggestions for this discussion: (1) Keep loaded and un-loaded motor rpm/speed comparisons separate or clearly delineated and (2) discuss no-load max rpm in rpm only (not speed). This will remove a lot of conversion mistakes and unnecessary effort.

Neat tool: Set CA wheel circumference to 1666mm, and units to kph, and the CA will read out in rpm (rpm = displayed kph x 10).

Best,
MLC
 
No worries MLC...nothing negative taken...I just felt the need to point out that there's nothing 'slow with my set-up' after it was suggested.

I'm not great with maths, and don't really understand exactly how all the RPM stuff works, but reading back over the discussion, I realise that my results actually do line up with the simulator if I there is about a 30% speed difference between the 4T and 5T as indicated by the Kv differences.

Cheers
 
Well Madin, what do you know, learn something every day :)
Note to myself:
Leaf 35mm 4t - 120km/h with wheel of the ground at ovs 0 and 18s battery (no OVS needed for me, it is already to fast)
MXUS3k 4t - 72km/h with wheel of the ground at ovs 0 and 18s battery
MXUS3k 4t - 85km/h with wheel of the ground at ovs 2 and 18s battery
MXUS3k 4t - 110km/h with wheel of the ground at ovs 4 and 18s battery

Will I feel better torque at same power output if swapping for 5T?
 
Then why go for the 5T? Is it more efficient at lower speed, draw less amps?

I was going to buy a 5T for my Flux beta in 26" wheel, there must be something better with 5T than 4T?
 
Yes but there must be something else than speed that is the difference, otherwise everyone can go say 4T and run on lower (cheaper) voltage to desired speed. I guess they draw difference amps at difference speed or something else? Will try to read the thread on the computer tonight to see if the answer is in the thread, if no one can tell me before that.

Guess this not unique to the leaf.
 
Swe said:
Yes but there must be something else than speed that is the difference, otherwise everyone can go say 4T and run on lower (cheaper) voltage to desired speed. I guess they draw difference amps at difference speed or something else? Will try to read the thread on the computer tonight to see if the answer is in the thread, if no one can tell me before that.

Guess this not unique to the leaf.
Click to expand...

if you have lets say a 4T motor and you run 72V and 60A, you would get EXACTLY the same motor performance (torque and speed) if you choose same motor with 6T, but with 6/4 the volts and 4/6 the amps, -> so 108V and 40A.
Or you could use a 2T and run 36V and 120A. would lead to same power.
Well, why it is not wise to use a 2T and 36V?
the reason is current available controller have theire sweet spot (performance / dollar) at 80-90V (usually 100V FET's and Caps). additionally lower amps will lead to lower losses in the wires (if you double the amps, you would need to use 4 times larger wires and a controller with 4 times less FET resistance for keeping losses equal)

if performance / dollar, and low losses is important for you, you should do like this:

decide for a battery voltage (keep the controller sweet spot in mind)
choose the wheelsize that fits your needs or fits the vehicle (smaller wheels mean more thrust at a given motor torque so its better for performace, larger wheels usually will improve the handling and riding comfort -> make compromises)
decide for a top speed you like to have
than choose a turn count that gives you the speed
 
Yup, what madin88 said exactly, basically it's the limit of the controllers that determines what windings are chosen. People who think a higher winding has more torque have just bought into a misconception perpetuated by marketing hype.

Personally, I don't mind running a 4T on lower voltage (12S ~45V) because I can run my controller (Adaptto Mini-E) on OVS to gain more top speed on the odd occasion that I need/want it, which isn't very often.

There is also a slight 1-2% efficiency gain to be considered in running a motor at/near it's top speed for a given voltage vs limiting a higher speed setup in speed due to controller PWM switching losses. i.e. a 12S (45V) pushing a 4T motor at 50kph (100% throttle) is going to be 1-2% more efficient than 18S (66V) pushing a 4T motor at 50kph (~75% throttle).
I'm not exactly sure why this is the case, but I believe it is something to do with the PWM relationship once full speed at 100% throttle is reached or approached, hence the switching losses at lower speeds.

The bigger consideration however in reality is how it will be ridden. I used to run 18S, but found I would still just WOT and go as fast as possible even with higher (more dangerous) top speeds available. This lead to many very sketchy encounters, and a lot less range than I would have otherwise enjoyed.
Dropping the speed of my bike was a consideration for both safety and range in the end.

And yeah, this all applies to more than just the Leaf, but I like these motors.

Cheers
 
Correct me if I am wrong but another consideration is that a smaller diameter rim puts the motor in a more efficient area and the motor stays cooler too. So you can climb those long hills without burning the windings.
Then when choosing a build from scratch; its wise to buy the smallest tooth count (higher speed) motor available and build around that. Example: Buying a 3T motor, then choosing a controller and battery configuration.
 
Markz, this is my understanding also.
I guess the catch is, using a smaller wheel isn't always practical...especially on a bike intended for off-road use.

The other consideration is that a lower turn motor will be harder on a controller at lower speeds. i.e. I wouldn't recommend a 6Fet Infineon for a 3T winding on any voltage, but a 9 or 12Fet should be ok.

Cheers
 
The stainless steel axle costs pretty mucha as the hole hubmotor.... I tried to over volt 9c and magic pie, it was fun but you will fry any motor doing 3x times the rated current. Get a fat hubmotor it will save you thousands of dollars.
 
Lurkin said:
Until you consider that there is a different volume volume of copper fill with the different T windings.....
Click to expand...
Yes, yet another factor to consider, which was also part of the reason I bought the 4T originally as it was thought that it had the most copper fill...it looks like people think the 5T now has the most?

Cheers
 
Great conversation. Thought I'd get into the mix.

First, I took my 5T 1500W Leaf for its first ride tonight. Big, fat, huge grin. First time I touched the throttle, the front end came up (yes). Max speed is exactly what the numbers from this thread and the simulator indicate it should be (~50 volts [with drop]/flats/no wind/300 lbs up to low 30's [mph] before I felt it stop pulling). As you can see from the pic I have some buttoning up to do. Yes, I rode it like that. (There's a 'before' pic a few pages back but it doesn't look much different.) No videos taken, but...just watch any video in this thread and imagine the speedo indicating 32.5 mph, and there you have it!!

Regarding the topic of "does more turns = more torque?", its as if some have an emotional stake in it. There's a thread around here (something about "physics") that goes into this deep and gets positively testy. But, I'm diving in anyway!....Fact is, 5 turns does provide more torque than 4 turns...wait for it...at the same current. So, an extra turn would help in a current-limited application. Of course, it'll have a lower top speed at the same voltage, too.

I chose the 5T because I have no desire to go 40+ mph on a bicycle (I have a motorcycle). Plus, I'm commuting on back roads (slower speeds, wide speed fluctuations, intersections, rough patches) and through some city traffic near the end. The 5T will be more efficient (and suited) for this (as stated already). It's sort of like choosing a gear to be stuck in. Between 3rd and 4th, I chose 3rd.

As implied in this discourse, one is not better than the other. They are just different and suited for different applications.

And yes, the 5T (13*5 / 65 strands) has one more strand than the 4T (16*4 / 64 strands).

Best,

MLC
 

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Cowardlyduck said:
Personally, I don't mind running a 4T on lower voltage (12S ~45V) because I can run my controller (Adaptto Mini-E) on OVS to gain more top speed on the odd occasion that I need/want it, which isn't very often.
Click to expand...

Interesting combo (if I could fit 2x 12s5p, =10p, in my bike..).
How fast do you go with this, 50km/h? How fast with OVS? What happens with the motor then, drain battery fast, motor heats up? How quick?
 
Good info on the 5T, i especially agree with choosing the wind according to your needs.
Here in Stockholm going 60+km/h on our awesome bike lanes is asking for trouble.
I am planning on running 5T on 12s LiPo for a max speed of 50km/h and lots of torque.
Thanks for sharing.

MLC said:
First, I took my 5T 1500W Leaf for its first ride tonight. Big, fat, huge grin. First time I touched the throttle, the front end came up (yes). Max speed is exactly what the numbers from this thread and the simulator indicate it should be (~50 volts [with drop]/flats/no wind/300 lbs up to low 30's [mph] before I felt it stop pulling). As you can see from the pic I have some buttoning up to do. Yes, I rode it like that. (There's a 'before' pic a few pages back but it doesn't look much different.) No videos taken, but...just watch any video in this thread and imagine the speedo indicating 32.5 mph, and there you have it!!
I chose the 5T because I have no desire to go 40+ mph on a bicycle (I have a motorcycle). Plus, I'm commuting on back roads (slower speeds, wide speed fluctuations, intersections, rough patches) and through some city traffic near the end. The 5T will be more efficient (and suited) for this (as stated already). It's sort of like choosing a gear to be stuck in. Between 3rd and 4th, I chose 3rd.
Click to expand...
 
Swe said:
Interesting combo (if I could fit 2x 12s5p, =10p, in my bike..).
How fast do you go with this, 50km/h? How fast with OVS? What happens with the motor then, drain battery fast, motor heats up? How quick?
Click to expand...
I get about 55-60 without OVS. I haven't done much playing with OVS, but OVS 1 gets about 65-70, and OVS 2 gets about 75. It does add a bit of extra heat, but not much as your going so fast the wind keeps things cooler. It definitely sucks your battery though, and I would not recommend it if you want to sit at those higher speeds for a long time.
For an indication of my average type of riding see this video from a ride I did yesterday:
[youtube]5KHLNqCifjY[/youtube]

It's this type of lower speed with a few higher speed sections type riding that makes the 4T Leaf Motor and 12S LiPo combo work so well for me. :)
Although right now I'm still running with my old HS4080 until I do a bit of an overhaul on the bike.

Cheers
 
I was thinking 18650-cells if I was going 12S but should be same voltage/speed?
I will normally not run faster than 50km/h, but maybe around that on good roads. And then when on straight roads with asphalt I sometimes want to take shorter speeding above that just because I can. Does it sound like it could work for me too? Or how much is "long time"?

I will only try this if I can get 10p to have lots of Ah, otherwise I guess I will take a 5T instead but with higher voltage.
 
Cowardlyduck said:
Lurkin said:
Until you consider that there is a different volume volume of copper fill with the different T windings.....
Click to expand...
Yes, yet another factor to consider, which was also part of the reason I bought the 4T originally as it was thought that it had the most copper fill...it looks like people think the 5T now has the most?

Cheers
Click to expand...

I've always been of a mind that 5t has the most based on info from Leaf itself. I posted about it earlier in the thread. Of course, could be wrong, welcome to advise of a way to measure it (within reason) I have a 5t on the shelf, new and unused....
 
Swe said:
I was thinking 18650-cells if I was going 12S but should be same voltage/speed?
I will normally not run faster than 50km/h, but maybe around that on good roads. And then when on straight roads with asphalt I sometimes want to take shorter speeding above that just because I can. Does it sound like it could work for me too? Or how much is "long time"?

I will only try this if I can get 10p to have lots of Ah, otherwise I guess I will take a 5T instead but with higher voltage.
Click to expand...
Sounds like 12S with a 4T is a good option for you, but it mainly depends on your controller. If you have a 12Fet or higher Infineon, then it would be fine, but anything less I would just go with a higher voltage and a 5T motor.
If you get an Infineon controller with a programming cable and 3 speed switch you can always program in 120% throttle. I do this on my Recumbent commuter and push the standard top speed of 40Kph up to 50Kph on 12S 4T Golden motor in a 20" wheel.

Lurkin said:
I've always been of a mind that 5t has the most based on info from Leaf itself. I posted about it earlier in the thread. Of course, could be wrong, welcome to advise of a way to measure it (within reason) I have a 5t on the shelf, new and unused....
Click to expand...
I think you might be right. Kinda makes me wish I did get the 5T, but given I push 4-5KW through mine it's probably a good thing I got the 4T.

Cheers
 
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