Leaf / leafmotor / leafbike high efficiency 1500w motor

[ZeroEm]

I'm 75 miles south of Austin, TX. Figure that my trike is a Class 3. Peddle at 28 mph, 750w, want a sticker that states that. But its a lie, outside of ES members there are few who can tell. Most people don't even know my trike is electric, even with the big leafmotor. Maybe because it's a tadpole trike, some think it is a broken bicycle.

Toecutter's endeavors keep my attention. Aerodynamics is a great way to speed. My thinking is always changing on here. I think the light is coming just not there yet. Justin opened my eyes about efficiency, you can take a low turn motor and use less watts than a high turn motor. Just need to find where that is for that motor, mostly around 50% of max rpms. I'm a peddler but don't want to slow down going uphill but takes me less than 1500w to pull 99% of the hills at 20 mph/32 kph. Some day I might want to go faster and have more power. All I need is a better controller and make my trike handle better at speeds above 35 mph. I fear that when I cross that line will not have a bike anymore and everything will get big and heavy, look like some type of motorcycle.

Right now I am under the radar the police just look and smile at me .

 

[sleepy_tired]

There are plenty of good choices for running a reduction drive. The Astroflight motors that are available can peak over 95% efficiency, and can pack a lot of power in a small package.

I would want something larger and more suitable for traction motor. Each stage of reduction represents a significant increase in expense and efficiency losses. Increases part count and reduces reliability as well. These issues is what makes direct drive so nice a option for lower powered vehicles. Less is more, but sometimes more is required due to packaging constraints and power requirements.

So if I can get away with a single stage reduction.. like just a single chain and couple sprockets, then that would be very nice. I don't know if chain versus belt would be better though. Chains are a bit more efficient, but may not be best if you want to have torque go both ways for things like regen.

 

[sleepy_tired]

I fear that when I cross that line will not have a bike anymore and everything will get big and heavy, look like some type of motorcycle.

It's better to have a specialized bikes for different purposes then trying to have a do-everything bike. Trying to dream up a bike that goes miles at a 100 mph that can pedal and weighs less then a hundred pounds is kinda nuts.

For a bicycle 35mph is fast, but in reality it's ridiculously slow. A 750 dollar scooter from China will blow the doors off such a vehicle. Even the cheapest and weakest motorcycle you can buy in the USA with a displacement greater then 50cc has little issue maintaining 55-65 mph.

When it comes to speed weight is your friend. Strong brakes are heavy brakes. Strong suspension is heavy suspension. Strong frames are heavy frames. Sure there is wasted weight and stupid ways to make things heavy that doesn't make them stronger, but if things are engineered correctly then heavy is good. Heavy means fast. Bigger suspension, bigger engines, bigger brakes, bigger wheels... these are all good things.

My little cheap Mitsubishi economy car will get better gas mileage on the interstate then some big cruising motorcycles despite weighing twice as much as having twice as many wheels touching the ground. This is because motorcycles are some of the worst aerodynamically performing vehicles possible. My little 75hp motor will propel two people with luggage quite comfortably and with no drama at 95mph. Which is a speed I have done by accident on long straight boring stretches of road.

The reason I like ebikes bicycles is because they are cheap and light and I don't need to go fast. I can pedal around like a idiot, go exploring, carry the bike up stairs and all that sort of stuff. I can't do that with a 100mph vehicle. I can comfortably still go anywhere I want as long as it's within 50 miles of where I start. If I want to haul a bunch of stuff around I can add a trailer. They are fantastic and practical vehicles. Just not very fast.

If I wanted a ebike that goes 35 (as in actually goes that speed, not just touch it for a mile or two) I would want a ebike that goes 55. I don't want pedals on that thing because pedaling is worthless at those speeds. I'd buy a used Honda Ruckus or some other scooter-like vehicle and then throw a big motorcycle hub motor on it or something like QS motor's scooter assembly and then have something that is actually engineered to go faster safely.

 

[The Toecutter]

I feel like you're analogous to someone who has a horse, but who instead of riding it, goes to great length to design and build a complex and fragile mechanical capsule around the horse that will allow the horse's natural gallop to carry him at double the horse's natural speed.

I don't see how that analogy would apply considering I ride this vehicle every day. I have over 40,000 miles on it, with no motor. The current body shell, the 2nd one I have built, while not the most durable thing in the world, already has more than 4,000 miles on it placed on it during the last 6 months.

AND it is the fastest, most fun, and most practical bike I have ever owned. I can load 2 weeks worth of groceries in the trunk space. I don't have to worry about losing my balance and falling off, which on a normal diamondframe bike will usually mean hitting the pavement face first from a height of 6 feet. I have protection from the sun and rain. Car operators treat the vehicle with more respect than they would a normal bike because it looks like it would damage their car if they hit it, and it is also more visible. The body shell also does supply a rudimentary amount of collision protection, that even though it would not fare well against vehicles 15x the laden mass, it is preferable to a normal bike in this regard. Most importantly, as long as I'm not going up too steep of a hill, on most streets, I can maintain flow of traffic speeds in city conditions, given that cruising at almost 25 mph on flat ground is no problem for me, and I can reach 37 mph in an all-out sprint, which means there is a reduced speed differential between me and the auto traffic in most cases versus a normal bicycle or even most street legal e-bikes.

In fact, I've raced people on street legal e-bikes, you know, the ones you can buy that only make about 750W and top out at 20-28 mph, and had no problem leaving them behind the vast majority of the time. The only time I cannot keep up is on long climbs up hills of more than 10% gradient.

Here's a video of me pedaling it at 30-40 mph:

https://vimeo.com/284616898
https://vimeo.com/284616919

That body shell has since been removed and I have a more slippery one on the trike now. This second shell is also incomplete as I am trying to perfect some aluminum wheel farings for it as well as a bubble top and turtledeck. Just think of what an electric drive is going to do for it!

I mean, sure... I guess. But at what cost? And in the service of what?

My total build cost when this prototype is finished as an EV will be less than that of a decent mid-range road bike purchased new, and way less than a purpose-built triathlon bike. The idea was to build transportation that is as car-like as possible in terms of weather protection/convenience/speed/safety without all of the expenses that come with using a car, that, isn't completely dependent upon an oil or energy company for its fuel and can be operated without these fuels needed if desired, the usage of the vehicle thereof having minimal environmental impact, and to also serve as a test platform for future vehicle designs. The user, if careful, could also get away with operating it without a license and have it pass as a street legal e-bike in cases where it isn't.

My first electric velomobile won't reach the lofty goals of 80+ mph and fast acceleration I mentioned earlier, but a 60 mph top speed, safe cruising speed of 30-35 mph, 0-30 mph acceleration of 4 seconds, and 150+ miles range at 30 mph, are all currently within grasp for this first vehicle with the components I have in my possession.

I have in mind eventually ditching the KMX frame and creating a modular platform that can span multiple vehicle types ranging from a purely pedal powered velomobile all the way up to a single-seater race car that has no bicycle drivetrain at all, and anything in-between. This way, if I ever start building and selling vehicles, I can keep the labor and parts cost down, and have a wider market for my product.

Wouldn't it be easier to simply live closer to the things you want to get to?

Not necessarily, that takes extra money that I don't currently have coming in.

Or less ideally, take a little longer to get there?

I value having free time to work on things. Depending on the distance involved, the speed differential can not only eat that free time up completely, but even turn "a little longer" into "impossible/not viable".

Or at worst, appease your derangement with speed and just drive a godforsaken car?

Very few cars appeal to me. For the most part they are bloated, piggish, clumsy, thirsty things that suck all the joy out of operating a vehicle. They also cost thousands of dollars per year to operate, money which I don't currently have. I love cars, this being said, but I like them small, agile, efficient, easy to repair, relatively inexpensive to operate, and fast, which the current offerings from the auto industry do not check all those boxes. I do have an electric Triumph GT6 conversion I built that runs and drives, but it is not yet finished and will require more work/time/money to become reliable, more of each than it would take for me to finish the velomobile that I am currently using on a daily basis.

 

[The Toecutter]

I'm 75 miles south of Austin, TX. Figure that my trike is a Class 3. Peddle at 28 mph, 750w, want a sticker that states that. But its a lie, outside of ES members there are few who can tell. Most people don't even know my trike is electric, even with the big leafmotor. Maybe because it's a tadpole trike, some think it is a broken bicycle.

I have the opposite problem. I move so fast people think my vehicle is electric. I've been pulled over by many police over the last two years and now they no longer pull me over because they know what the vehicle is: a bicycle. I can use this to my advantage, since I am going to keep the electric drivetrain hidden and the bicycle drivetrain plainly visible, and for locations where there is a 28 mph/750W limit with PAS, I will have a setting for that in my CA computer, as well as an "offroad" setting. There will be no way to prove I was operating it illegally unless I get caught doing something stupid(like going 50 mph up a steep hill).

I fear that when I cross that line will not have a bike anymore and everything will get big and heavy, look like some type of motorcycle.

You need to then build something that meets your wants for speed as much as is possible, that doesn't get big and heavy. I'm keeping a weight limit of 100 lbs in mind for my builds, and designing it to still be pedaled with the EV system off is a good test for efficiency. If it fails to be within 10% of the effort required to pedal a normal unassisted trike at 15 mph, back to the drawing board...

 

[The Toecutter]

Trying to dream up a bike that goes miles at a 100 mph that can pedal and weighs less then a hundred pounds is kinda nuts.

The laws of physics allow for such a build. The question is whether we will ever have all the components needed to make that build possible. Right now, today, with readily available off the shelf parts, one can build something that between a normal bicycle and that nuts concept, gets well more than halfway to that nuts concept, but is riddled with compromises to do so.

For a bicycle 35mph is fast, but in reality it's ridiculously slow. A 750 dollar scooter from China will blow the doors off such a vehicle. Even the cheapest and weakest motorcycle you can buy in the USA with a displacement greater then 50cc has little issue maintaining 55-65 mph.

All true.

When it comes to speed weight is your friend. Strong brakes are heavy brakes. Strong suspension is heavy suspension. Strong frames are heavy frames. Sure there is wasted weight and stupid ways to make things heavy that doesn't make them stronger, but if things are engineered correctly then heavy is good. Heavy means fast. Bigger suspension, bigger engines, bigger brakes, bigger wheels... these are all good things.

More weight also begets more weight, since you need sturdier components to be able to withstand its consequences at higher speeds. Design optimization can yield components that are light enough for the application, as well as being strong enough for the application. One needs to look at this from the standpoint of Paul MacReady designing the GM Impact or Gordon Murray designing the T.50. Every system has to be designed with consideration in mind to how it affects every other system in the vehicle, so that you can have a part reliably and safely perform the task it needs to do with as little mass as possible.

DOT rated motorcycle components are way too heavy and are meant for 400-600+ lb vehicles, whereas bicycle components are too weak. There's a middle ground between the two that can be found to suit the application, but the components have to be custom designed for it as from what I can tell, for the most part, they don't currently exist.

The reason I like ebikes bicycles is because they are cheap and light and I don't need to go fast. I can pedal around like a idiot, go exploring, carry the bike up stairs and all that sort of stuff. I can't do that with a 100mph vehicle.

The reason you can't do that with a 100 mph vehicle is because a 100 mph vehicle has never been designed with that functionality in mind, and the market has not come up with components optimized for the task. I have 10 years engineering experience, so my perspective may seem a bit "nuts" to most people reading my posts.

If I wanted a ebike that goes 35 (as in actually goes that speed, not just touch it for a mile or two) I would want a ebike that goes 55. I don't want pedals on that thing because pedaling is worthless at those speeds.

Once I convert my trike, I will have exactly what you describe, except that thanks to drag reduction, pedaling won't be worthless at those speeds. At 35 mph, I could leisurely pedal with 120W and have that account for overcoming 1/3 of the vehicle's total load, which also extends my range by 50% versus while riding at that speed purely by throttle. On a normal upright e-bike, that same pedaling effort would extend range only about 10%.

 

[Davidcroatia]

Are all these generic Chinese controllers compatible with the leaf motor and LCD 8 screen?

The motor doesn't care what controller is pushing it.

This isn't true anymore. Some of the cheapest controllers still send the motor a more squared waveform in the pulses sent down the phase wires, and some send squarish pulses that more approximate a sinus waveform for more quiet operation most noticeable during takeoff where the square wave controllers have a knocking sound during takeoff. However, a motor has its best and most efficient operation when the waveform sent from the controller matches the shape of BEMF produced by the motor, which isn't necessarily a sinus waveform. That's where the newest breed of FOC (Field Oriented Control) controllers come into play. They can make our motors run cooler and more efficient for the same work output, which shows up as a noticeable decrease in consumption and increased range, so while they cost more they can actually pay for themselves in the long run.

With some of the FOC controllers, such as the Nuculars that I now use, you get a lot more advanced features that make increased efficiency just icing on the cake. Plus they're a lot smaller than what we're used to with the cheap China controllers. I just got my first Micro Nucular 6F in today and it's just over 1" thick by 2" wide by just over 3" long and despite its size can handle any voltage up to a 22s battery and can handle up to about 90A battery current and 120A phase current. With things like torque throttle, variable regen braking, and simple to program current and throttle tuning, it makes any ebike more pleasant to ride. It's also super easy to set up, just connect the motor wires to the controller, set the pole count (the default is the 23 pole pair that's so common like on the Leaf), and run the auto-setup function, which automatically figures out the wiring and tunes for the voltage output of your throttle and brake. If the motor runs backward after setup, just swap any 2 phase wires and it's ready to go in forward. I haven't even scratched the surface of the functions available, and more are added several times a year via easy to install firmware updates.

I assure you the less than $250 spent on an advanced Nucular controller with display for easy programming and live data like speed, voltage, controller and motor temps, and much more, is a purchase you'll never regret. That's coming from Mr. Frugal who stayed with cheapy Chinese controllers longer than he should have, and because my motors are 6 phase I have to buy 2 controllers for every motor, and it's still worth every penny and more. When you spend $500 or more on a cell phone, but turn around and want to buy a $20 controller for your ebike, it's not a wise savings. Sure prices will come down significantly with mass production, but some of the required components are too costly to ever be like the Chinese super-cheapies, and mass production is still too far away to wait.

how much in range are we talking about compared to sinewawe ? Can i buy in europe that controller?

 

[ZeroEm]

how much in range are we talking about compared to sinewawe ? Can i buy in europe that controller?

Your not going to get an answer to that question. You would need to setup a test to figure that out. Everyone want more power and range with less battery. If you want range you buy efficient motors and controllers, keep your speed down and peddle. Then come on here and brag about it.

I have been looking a 700C wheels with a low Turn motor and keep it around 15mph/24kph would use the lowest watts than other setups.

 

[John in CR]

how much in range are we talking about compared to sinewawe ? Can i buy in europe that controller?

My motors ran silently on older trap controllers, so I never had to switch to sinewave. I'll be changing another bike over to Nuc's quite soon, and it has a CA3, so I'll do a long run with a mix of highway and city riding over a set course and easy to repeat speeds before and after the change, and leave the CA on the bike. I hate to state a % improvement claim without being more scientific about it, since I don't really pay much attention to consumption now that I haven't had a regular commute for 2 years. I changed over one bike about 9 months ago, and I have noted that I charge less frequently and the motor runs significantly cooler, so I'm confident that there's been an improvement in overall wh/km with the switch and I'm quite sure that I haven't been riding more slowly. One contributing factor though is that regen is definitely a larger % of my braking.

They're produced in Russia and they use the European courier service DPD, so anywhere in Europe is easy. Check the For Sale section here in the forum for more info. You do have to be patient though as Nucular has a big order backlog, but you don't pay until your controller(s) is ready.

 

[John in CR]

how much in range are we talking about compared to sinewawe ? Can i buy in europe that controller?

Your not going to get an answer to that question. You would need to setup a test to figure that out. Everyone want more power and range with less battery. If you want range you buy efficient motors and controllers, keep your speed down and peddle. Then come on here and brag about it.

I have been looking a 700C wheels with a low Turn motor and keep it around 15mph/24kph would use the lowest watts than other setups.

It will be nice to run such a low voltage. You must have a very light load to run those big wheels. Even then I don't see how it's the most efficient in the simulations.

 

[ZeroEm]

by John in CR » Sep 11 2020 7:35pm

ZeroEm wrote: ↑Sep 11 2020 7:15pm
how much in range are we talking about compared to sinewawe ? Can i buy in europe that controller?
Your not going to get an answer to that question. You would need to setup a test to figure that out. Everyone want more power and range with less battery. If you want range you buy efficient motors and controllers, keep your speed down and peddle. Then come on here and brag about it.

I have been looking a 700C wheels with a low Turn motor and keep it around 15mph/24kph would use the lowest watts than other setups.
It will be nice to run such a low voltage. You must have a very light load to run those big wheels. Even then I don't see how it's the most efficient in the simulations.

Just in Grin's Motor Simulator. May not work in a real application. Just some thoughts Justin put in my head. Watch his video on efficiency and he will explain it.

Wanting to build a high racer/700c recumbent E-bike. try to keep the motor, controller and battery light/small for riding with the road biker's on Sunday morning rides, about 30 miles. May not even like that type of bike but i'm stuck with recumbent's.

Will keep my current trike as is. In a few more years as I gain experience might dabble with a faster more powerful bike/trike.

There is a drag strip not to far from me could build a dragster trike and see what speed and times I could get.

 

[theloadedquestion]

Hey all,
I've been struggling to find a good controller to match with my 1500w leafbike motor, keeping in mind my desire to flirt with the motors' potential limits. I've already gone through two controllers, including the 55a max controller from leafbike, which was even worse than the 40a cont. one I replaced it with.

I'm now looking at either the phaserunner or this powervelocity controller
http://powervelocity.com/home/48-18...r-android-ios-bluetooth-programmable-8kw.html
What do you guys think for this motor?
Thanks

 

[The Toecutter]

There are a lot of good choices out there. I have a Phaserunner in my possession that can go up to 72V nominal and 96A battery and phase current, but even that won't push this motor to its limits.

You could try an ASI BAC8000 and limit the phase current to around 150A. Any more than that and you're liable to burn the motor up. There are other options that are similarly powerful.

I hope you have good torque arms, brakes, and tires.

 

[Balmorhea]

I've been struggling to find a good controller to match with my 1500w leafbike motor, keeping in mind my desire to flirt with the motors' potential limits.

Don't tell me--what you think those limits are is way more than what the motor's manufacturer thinks its limits are.

Good luck with that. Come back with aftermath pictures.

 

[John in CR]

What do you guys think for this motor?

Get yourself a Nucular 12F and a matching display. It's worth the wait, super easy to get running using the auto-setup function, with tons of features you'll never go without again like torque throttle, field oriented control (FOC), variable regen, and if you want extra speed true field weakening, plus much more. It's an investment you'll never regret. Oh and despite being more powerful than the controller linked, it's much smaller.

 

[theloadedquestion]

What do you guys think for this motor?

Get yourself a Nucular 12F and a matching display. It's worth the wait, super easy to get running using the auto-setup function, with tons of features you'll never go without again like torque throttle, field oriented control (FOC), variable regen, and if you want extra speed true field weakening, plus much more. It's an investment you'll never regret. Oh and despite being more powerful than the controller linked, it's much smaller.

They certainly look like nice controllers, but with a 4+ month backorder wait, and the requirement to buy a separate "on-board" computer to program it I'm not sure. Then again I'm not in a huge hurry so maybe I'll just wait and see where things stand in a few months. Thanks guys. So few options, sigh.

 

[ZeroEm]

no one disagreeing with the few options.

The e-bike market may have more options in the future. At the moment most controllers for bikes are cheap and low power. Then higher power expensive and a big box for mopeds/motorcycles then you get into the EV's. with the power they get big and cost and still not good.

John in CR is pointing you to the best deal we know of for cost, size and power. There are lots of threads that talk about other high power controllers. They cost more may not be better and are bigger.

 

[John in CR]

What do you guys think for this motor?

Get yourself a Nucular 12F and a matching display. It's worth the wait, super easy to get running using the auto-setup function, with tons of features you'll never go without again like torque throttle, field oriented control (FOC), variable regen, and if you want extra speed true field weakening, plus much more. It's an investment you'll never regret. Oh and despite being more powerful than the controller linked, it's much smaller.

They certainly look like nice controllers, but with a 4+ month backorder wait, and the requirement to buy a separate "on-board" computer to program it I'm not sure. Then again I'm not in a huge hurry so maybe I'll just wait and see where things stand in a few months. Thanks guys. So few options, sigh.

You don't pay until your order is ready to ship. Right when they were starting to hire employees and really expand production the virus hit, which delayed some parts supplies. In the meantime demand kept increasing so things are more backed up now that some issues have eased. I'm as frugal as they come, so a small aluminum box of electronic bits costing more than a motor rubs me the wrong way, but proper pricing can't come until there's mass production and apparently there are some expensive parts inside FOC controllers. After 12 years of frustration with the slow advancement of controllers and inadequate throttle control over powerful motors, I finally bit the bullet and opened the wallet up a bit, and I'm so glad I did. You've gotta look at it as an investment, one that helps support the forum member who spent 2-3 years on development right here on the forum. The display simply makes setting changes easier, as well as gives you a way to connect and control new devices, whether it's the available bms, the lighting system still in beta testing, advanced PAS, or even use any DC power source with a voltage below pack voltage as a charger for your bike with the controller in full control of the charge settings and limits.

 

[theloadedquestion]

Thanks man, appreciated. I'm in, sold.

What do you guys think for this motor?

Get yourself a Nucular 12F and a matching display. It's worth the wait, super easy to get running using the auto-setup function, with tons of features you'll never go without again like torque throttle, field oriented control (FOC), variable regen, and if you want extra speed true field weakening, plus much more. It's an investment you'll never regret. Oh and despite being more powerful than the controller linked, it's much smaller.

They certainly look like nice controllers, but with a 4+ month backorder wait, and the requirement to buy a separate "on-board" computer to program it I'm not sure. Then again I'm not in a huge hurry so maybe I'll just wait and see where things stand in a few months. Thanks guys. So few options, sigh.

You don't pay until your order is ready to ship. Right when they were starting to hire employees and really expand production the virus hit, which delayed some parts supplies. In the meantime demand kept increasing so things are more backed up now that some issues have eased. I'm as frugal as they come, so a small aluminum box of electronic bits costing more than a motor rubs me the wrong way, but proper pricing can't come until there's mass production and apparently there are some expensive parts inside FOC controllers. After 12 years of frustration with the slow advancement of controllers and inadequate throttle control over powerful motors, I finally bit the bullet and opened the wallet up a bit, and I'm so glad I did. You've gotta look at it as an investment, one that helps support the forum member who spent 2-3 years on development right here on the forum. The display simply makes setting changes easier, as well as gives you a way to connect and control new devices, whether it's the available bms, the lighting system still in beta testing, advanced PAS, or even use any DC power source with a voltage below pack voltage as a charger for your bike with the controller in full control of the charge settings and limits.

 

[Djhandz]

Hi guys I am currently running my leafmotor on 18s lipo 75v fully charged. I have another 4s pack that I used to use with my mxus. Can I add this 4s pack and run 22s 96v fully charged to give a little extra range?? I normally pull around 4000w bursts but most of my riding is around 250-1000w with pas
So my question is can I run 96v to this motor providing I keep an eye on the temps

Thanks guys

 

[Cowardlyduck]

So my question is can I run 96v to this motor providing I keep an eye on the temps

I ran my Leaf at 7.5Kw with active cooling fans. Worked well. Temps could reach over 120C on big hills or hot days, but mostly it was ok.
The limiting factor is more likely to be your controller depending on the motor wind. I had a 5T and ran 52V.

Cheers

 

[Balmorhea]

Hi guys I am currently running my leafmotor on 18s lipo 75v fully charged. I have another 4s pack that I used to use with my mxus. Can I add this 4s pack and run 22s 96v fully charged to give a little extra range?? I normally pull around 4000w bursts but most of my riding is around 250-1000w with pas
So my question is can I run 96v to this motor providing I keep an eye on the temps

Phase current is surely more of a factor than voltage, though running higher voltage means you'll likely spend more time in a lower efficiency range (making more heat).

There's nothing about the voltage by itself that would be a problem.

 

[Djhandz]

Thanks guys...it's just I have the 4s pack sat there doing nothing so thought I might be able to put it to use. I could rearrange my packs and run a lower voltage but with 3x6s and 1 4s it's a little difficult as I have no experience splitting lipo packs

Thanks again

 

[John in CR]

Thanks guys...it's just I have the 4s pack sat there doing nothing so thought I might be able to put it to use. I could rearrange my packs and run a lower voltage but with 3x6s and 1 4s it's a little difficult as I have no experience splitting lipo packs

Thanks again

Don't pay attention to Balmorhea's incorrect statements, the controller converts what comes from the battery to the apparent voltage the motor needs to run the speed you ask for with the throttle. Adding the 4s to your 18s will be an increase in capacity, not a decrease in efficiency. While it will be more difficult to not use any of the extra performance possible with the increased pack voltage, as long as you run at essentially the same speeds your consumption in wh/mile will be essentially the same, so efficiency the same.

People look at motor simulations and interpret the graphs to mean low speed = low efficiency, thus this erroneous concept of "lower efficiency range". The graph however represents what occurs at that throttle position. When you vary the throttle lower, then the efficiency curve shifts to a lower speed range. Below is a simulation to demonstrate this with the Leaf running an 18s pack and a 22s pack with the throttle position lower on the higher voltage pack so they run at the same speed. Notice that efficiency is virtually identical at 87%.

 

[Balmorhea]

Lower throttle settings are also less efficient, as your graph shows.

Not to mention folks are unlikely to change their throttle habits when adding a few percent more volts. They'll just ride a little harder.