Running multiple simulations I learned quickly that to improve the torque in the upper motor RPM range like I want, I just need more voltage and there's pretty much no getting around it! I'll probably keep patiently waiting for battery improvements and stick with the 20S pack for the time being *insert skeleton waiting meme*. It was also really interesting to see how the torque to RPM performance mapped so similarly between different brands of hub motors. Some lingering misconceptions I had really fell away with your explanations and comparisons. This was a very instructive video! Thanks for your efforts Justin, I really appreciate it. I wish your business and talented team catered a bit little more with e-bike products aimed at the 5KW-10KW "gray area" market that I like to play in, but totally understand all the reasons for not doing so.
You can get around it with a faster motor winding without a higher voltage battery, and you can somewhat get around it with field weakening which is increasingly a feature in better engineered controllers. Anyways glad to hear that you have been learning from this video and good luck with your higher power endeavors !
Who would like for Grin to make their own mid-drive? A real competitor to the Cyc x1 Pro, just much quieter would be awesome! Maybe a larger motor and lower rpm and belt drive. Ideally with so much power that you don't need really need a fragile gear system. While I love their hub motors, hub motors have the problem of ruining ride quality because of unsprung weight. Also hub motors tend to look more illegal.
So you want everything that stresses the drivetrain more AND a belt drive. Why not just get used to walking with the setup you have? It'll be a lot cheaper.
Man, you speak my language! Explain why language is spelled the way it is. Concise fact based presentation with opinion towards overall cost. Some of us want to go as far as possible, many will come to that conclusion once they dive into the e-bike Blue Hole. Just the facts Jack! Thanks, Richard
Thanks for a great presentation Justin. I would like to request that some future presentation includes the topic of using a motor as a pedal-driven generator. I understand that this might be a bit of a special request so maybe it can be included in the regen video you are planning. Thank you!
One factor that over rides all of the things you can do to increase efficiency/torque is COST. The mighty dollar makes the world go around just like electricity makes a motor go around :). Whether it is a higher grade of steel, more copper, tighter windings, etc...they all add cost so there is always a compromise of cost vs everything :). Justin...awesome job covering the variables, Thank You!
Batteries cost more than motors, and calling a taxi to drive you and your ebike home costs more than using the power you saved with a more efficient setup to drive yourself home.
A suggestion for increasing list of motors available to the motor simulator would be to have a how-to webpage or video explaining how people could measure this themselves and then crowd-source results. When two or more sources report essentially the same result that could be included on the list.
30:05 "The higher the RPM of the motor the more power it can generate and --more torque it can produce--" Is the torque part misspoken, because you forgot to add the "efficiently" part to the end of the sentence when you said it? The powerpoint page does have the "efficient torque production" written. I'm just getting a bit confused, as is my understanding that RPM doesn't affect how much torque the motor (PM-motors) can produce to an extent (losses), but does effect how efficiently it can produce it. Isn't stall torque the greatest amount of torque the motor can produce and I don't think it should be able to increase if you increase the RPM? I think there was a later part where you said the quoted sentence again, so I'm just asking for a clarification. I'm an electronics engineer who does electric skateboard building as a hobby and I've been logging and monitoring my board's performance and efficiency on my rides (as you do as an engineer, as you said :D) EDIT: Otherwise an excellent presentation and lots of great information!
You are 100% correct here so thanks for pointing this out. I should have said "power and EFFICIENT torque production" as is written on the slide. The motor can still produce high torques at low RPMs, but the efficiency of the motor is much lower in this scenario than when it produces that same torque at higher RPMs. Stall torque is mostly determined by the battery or phase current limits of the motor controller, it's not a motor characteristic but a system characteristic. If you are phase current limited by the controller, then the torque is totally flat and independent of RPM up until the speed where your you become either battery current limited or voltage limited. All of this is modeled on our motor simulator app (including a number of skateboard hub motors) so you can see the effect of different phase or battery current limits on the torque/speed line.
Is the equation at 1:00:08 correct? I am just slightly confused how Imotor=(Vmotor-Kw)/R Say if there’s a 72v battery back Vmotor= 71.6v K = 12rpm/volt RPM = 750 ~ 75rad/sec 71.6v-(75rad / sec * 12 rpm / volt) = negative number What am I doing wrong? How do you find Vmotor?
If you have Kv in RPM/V, then either you don't convert to rad/sec as you are using units of revolutions per minute. If you did want to convert into rad/sec, then 12 rpm/V = 1.257 Rad/sec/volt, = 0.796 V/rad/sec (which is the units of Kv in the equation) Vmotor is the voltage that the controller is sending to the motor (ie battery voltage times the duty cycle). Kw is the back-emf voltage of the motor. If it's 12 rpm/V, and your motor is spinning at 300 rpm, then Kw = 300 rpm / 12 rpm/V = 25V. Or if you are in rad/sec mode, 0.796 V/rad/sec * 31.42 rad/sec = 25V If you have a 72V battery pack, I can guarantee you that your motor controller is not going to be supplying 71.6V to the motor if the motor's back-emf voltage is just 25V, it would be limiting it based on either the phase current limit of battery current limits programmed into the controller.
Only in cases of motors with very high eRPMs where eddie losses are still significant even with 0.35mm stators. There are very much diminishing returns with thinner lams if eddie current losses are not a dominant part of the core heating. We have some MAC / GMAC motor samples with 0.2mm stators for evaluation to see if it's worth it or not.
good job..im glad you seperated eficiency from economy..i would have liked to be shown steeper hills and where hub motors start to sigh off/stall and how long a midrive with gears can hang in there....you shed a bit of light on my long time question "how fast to climb?" (but only for 6% grade) ... for my off road long distance bike packing/racing application i had come to the conclusion that mid drive was the only way that will work...this presentation has given me more to think about but as much as id like a DD hub motor to work in my application i have a feeling it wont work...having said that i might be able to mount a motor forward of the rear wheel and experiment with diferent gearing between rear wheel and motor only...you point out on climbs go fast 15kmph and cruze flat ground slow 20kmph (6% grade only) might be workable ish..off road climbing a steep hill or tight mountain track,15kkmph is very fast and 20kkmph out on a gravel or sealed road is slow ish....this application is asking for 2 gears for the motor to wheel only...i like that you pointed out with a mid drive to keep the human and motor sincronised in thair best rpm ....this suggest if building for a mid drive one strong ish assist level only so that you use that one assist level only and all the time with maybe a higher help level when the only other option is walk.but go slow on the flat....interesting that the 25kmph limited comercial bikes can climb fast and not go fast on the flat.....what you are pointing at for economy and using an electric motor looks very much like a single speed human gearing with a direct drive hub motor mounted forward of the wheel and geared lower...ooo we love simplicity:).....you nearly answered another long time question i have....how much energy are bl controllers using?..and can a brushed motor be more economical at our low motor speeds with out a controller or pwm ?
Hey Russel, hopefully if you watch and follow a bit more closely you'll see how you can replicate exactly the same kind of simulation runs that I did to quantify how things will be at even different grades or riding scenarios. As long as the really steep hills aren't too long then usually a powerful hub motor (like the GMAC or RH212) will be totally fine with this usage, but if you have looong steep hills to climb you may need to budget cooldown breaks for the motor otherwise they can go into thermal rollback. Brushless motors are generally cheaper than brushed motors for the same power and torque capabilities, so they are the more economical choice. A DC motor without any motor controller at all is not a very good idea and not very useful as you couldn't modulate the power independently of speed or use regenerative braking.
@@GrinTechnologiesyou say in relation to no controller. "you couldn't modulate the power independently of speed" there are ways to alter voltage with out a controller and if you run the human and motor through the gears you can modulate the power independantly of the speed or we can say that backwards. you can modulate the speed independantly of the power or we can say we can shuffle torqe power and speed with gears...however your talk hints that for economy for a mid drive we should be at an rpm that balences losses and matches the human rpm and for hub motor economy our speed need only change 5kmph (6% grade)..a controller would help(depending on its energy consumption) however one voltage/rpm would also work up untill a stall grade % ..rpm's past the loss balance rpm..althogh this goes biast toward the magnet losses it uses less and less battery power untill we get to zero power used/ no load ...then its human or gravity overcoming all drag......if a free wheel is used here stored energy in altitude can be used to coast if the down hill gets steeper...if no free wheel is used then you are driving the motor with gravity and this will create drag and electriserty....you say " can not use regenerative braking" i think you ment to say "can not use proportinal regen"?...you also say "Brushless motors are generally cheaper than brushed motors for the same power and torque capabilities, so they are the more economical choice." a 500 to 1000w brushed DC motor with out controller is $25 to $50 usd ......heres a question iv had for a while...how much power do BLDC motor controllers use specificaly in our aplications?
Temp vs efficiency: I read that when heated magnets produce weaker force, thus affecting motor performance. Is there any approx multiplier to estimate motor efficiency at different temperatures?
That is a superb question that I didn't get into at all in this presentation, but is totally true and yes at some temperature the magnets become weaker too which further degrades performances. You can see how the torque per amp starts to roll off here when the stator gets over 130oC endless-sphere.com/forums/viewtopic.php?p=218321#p218321 However, didn't have a temperature probe on the actual magnets to see what their temperature was at, and obviously different grade magnets are affected differently by elevated temperatures. In outrunner motors, the magnets can still be quite cool even when the copper is hot, but in an inrunner motor the magnet temperatures would get close to the copper temps, and this could further degrade performance in a measurable way. It's not modeled on our simulator though, only the increased winding resistance is there.
Thank you for great video! Very useful information. Very interested into section "optimal efficiency RPM vs Power", and my question here is if there are 2 identical motors but with different kv parameters, would they have different graphics or same? So if I need for example 5000w and I have motor with 8kv or 12 kv, what motor is better for 180rpm ?
Identical motors will be identical. Doesn't matter what the Kv is. At 5000 W and 180 RPM both motors provide the same torque. Both will perform exactly the same.
In addition to the correct comment here by difflocktwo, I did want to add that you will see a small difference in efficiency with the motor simulator tool with the two different windings, but that is because of higher controller losses in the faster motor wind. If you set the controller resistance to 0 ohms to only look at motor efficiency, then it works out to be the same.
@@GrinTechnologies If so, is there any reason to use low kv motor? Especially if the controller still can provide phase amps for high kv motor. For example, I have 120 A max phase current but use only 50 A and top speed is 42 km/h. I can swap motor for higher kv (double it) and get a boost to speed (even for a short time due to heating). Any downsides?
Thank you very much for the video, it made a lot of things clear to me! However, one point is missing: 5 km/h is not a realistic speed. Then you can dismount and activate the push assist and be MUCH more efficient ;-)
You said the trip simulator shows the battery efficiency and the motor simulator the controller efficiency. Do you multiply them to get the total system efficiency?
Is there any way to record real time data from a trip so that the data could be run thru the simulator to discover ways to increase efficiency if that trip is repeated. For example - say you do a repeated trip daily such as a commute to and from work. It would be very useful to analyze the parameters of your trip to see how changes to throttle use would effect battery usage or compare different routes to see which is more energy efficient. Would also be interesting to have a function to analyze a long trip to see what the power requirements would be if you do the reverse trip back home. Not sure how this could be implemented but just wondered if you have given any thought to try to develop this capability?
Best video of motors out there! Some are to general... Im designing a hub motor for a small vehicle, the weight of the motor is 170g and the gear ratio to the road is around 0,7 (direct drive). I have two of them so 300g, the car weight is 2.3 kg. But it has not much torque... Is there a scaling issue of motors?
Certainly small motors usually have worse efficiency and power density than larger motors, but at 170g you should still be able to get enough power to move half of 2.3kg vehicle quite well.
Excellent presentation. Does anybody know why there isn't more axial pancake design motors made, since they are more efficient and powerfull being smaller and lighter? I feel there is a market for this motor because of all the benefits
I can tell you that this question comes up all the time. I think most people who actually go about seriously looking into making one realize that the mechanical challenges with unbalanced forces required for a reliable axial flux motor in this power and size class outweigh the potential benefits. But that's not to say it can't be done and we would certainly welcome anyone overcoming those challenges and breaking new ground here!
When somone is asking for best efficiency on hills, is more like: - "I like riding fast, but also would like to do it at optimal efficiency of motor". Normally I ride MTB 25-30km/h flat and 15-20 on hills. Upgrading to ebike I would expect around 35 flat. So now is question what is optimal speed for motor efficiency on hills? Using as a reference point speed I'm cruising on flats. Because biking is mostly about physcial activity for me, I can do a little burnout in my legs on hills. So I can pedal 700W through 40s segment of hill. I dont care about aerodynamic drag. I kinda forgot what I really wanted to ask about. But mostly about motor efficiency and power distribution legs/motor.
For the most part, as long as the motor has sufficient torque to go up the hill at a decently fast speed is best to just key going fast. Let speeds have similar copper losses but stretched out over a longer time period so more total heat is generated. Humans will slow down to rather pathetic speeds on a hill climb, like 5-10kph. They're is no advantage to emulating that if you have a hub motor.
So do motor controllers with advanced features like FOC change the efficacy or is it like field weakening and just allows the motor to operate with a larger envelope. My non learned understanding of foc is its like field weakening in that it plays with the magnetic fields but with real maths to get the effects of optimal magnetic interaction for smooth mechanical force and in turn power efficacy.
In practical steady state terms, a field oriented controller behaves just like a sinewave controller but with always optimized timing advance. You do get better efficiency from the motor (by a couple percent) than you have from a trapezoidal drive, and you also have a faster increase in torque as the motor is loaded and slows down.
All I know is computer power supply. Peak efficiency would be around 50-80% of load and drop off any lower or higher than that. Does hub motors have same effect?
Not really. There is no analogy in a computer power supply to the widely varying rpm at which motors operate. Watch and follow the video if you want to properly understand what determines motor efficiency
Thank you Justin, great presentation! It is really DIP dive into this huge subject. I am still looking for the best answer to this common question: for a given DD motor/battery/controller which is the ideal 'uphill' speed to minimize overheat AND consumption?
If the rider is pedaling, then the least heat and least consumption is climbing the hill quite slowly. Then the legs to most of the work and the battery/motor less so. But if the rider is NOT pedaling or only pedaling with low effort, then you use exactly the process that I demonstrated in the video to make a simuilation set that plots the result. I was surprised to see that over a range of different motors and grade hills it almost always fell in the 15-20kph realm for lowest consumption. So that would be a simple answer if you don't want to get into details with a commoner.
@@GrinTechnologies Thanks, I'll keep in mind these indications. May be one day I'll invest half a day to perform some 'real life tests' with my actual setup. My power meter should also allow to derive more precise figures for each data set.
Is there a ''fast'' way to plot efficiency 3d plot ''island'' that we can see for many motors ? With a vehicule power requirement curve over it. Would be usefull fo hubmotors, Thanks
I don't know enough words in english to appreciate this presentation. And it will be 101% awasome if you record it in 1080p. Some text on screenshots isn't readable.
I have a Walmart 20" Kent torpedo bike 24volt and 180 watt hub motor without gearing.i would like to be able to make a 25 mile trip under power .it has a 5.4 amp hour battery can I use lead acid to work? What battery is cheap to achieve my goal
You can use lead acid, but a 24V 5.4Ah lead battery is just tiny and no way it would do 25 miles. Due to the peukert effect that's well under 100 Wh. You should be looking at more like 15-20 Ah with a 24V lead acid system for that kind of range.
Sir, I'm very much interested in your product. But I have a small dought to clarify, the thing is how a regenerative brakes offers constant current and constant voltage, although it is a highly complicated question or it is ur business secret. Can I Hook up a 60v ac on the motor phases to charge my battery? If yes, at how much is the maximum power I can get and is regenerative braking causes heating up of controller. That's all in my mind, I wish to have answers ASAP to buy your convenient products that are made for the performance. Thank you, sir for your time.
I'm trying to run a phase check program on a sabvoton 72100 controller and a qs205 hub. They did not send the short little stub electrical fitting that plugs into the display cable to run the hall sensor test. Any suggestions? Do you have a tutorial vid. on programming the two together?
If I lower my amps from the controller will it increase my range. Or could I accomplish the same thing by governing my speed? Or does either one even matter? Right now I have an 48v 24ah battery, a 40 amp controller, and a 3540 crystalyte hub motor and with throttle only I'm only getting about 30 miles. Is that normal? Would I get more range if I lower the amps from the controller?
Hi Randy, you get more range when you use less power from the battery, it's as simple as that. It doesn't matter if you do that by reducing the current limit of the controller or setting up a speed limit, but those two methods change how that reduced power is distributed along the ride. Lower current limit means you'll have less power climbing hills, accelerating and such but your top end speed is unaffected. A speed limit won't affect your low end power and torque but it will of course reduce your power once your are up to speed.
And 30 miles on a 1.1 kwhr battery is typical of a fast and power hungry setup like that. At more typical power levels and speeds your have 60-70 mile range.
At 1:20:28 With increasing speed I see you plotted a sharp climb in Motor Temp with increased speed? Sure increased wattage will raise the temperature but are you even factoring the massively increased "air cooling" to the hub motor as the speed increases? Think of it as a fan blowing on the wheel and hub. The faster you go the higher CFM of the fan to cool the motor. Also have you charted hub motor cooling with speed when using an "Aluminum mag Wheel" instead of spokes? Mag wheels have huge advantages for Ebikes as they act as a giant air cooled heatsink. Increased Air Speed helps cool the motor so are your motor temperate plots even accounting for air cooling and MAG wheels? If you make a simulation don’t forget with the MAG wheel rotating the bottom tire that touches the ground has ZERO speed. While the top of the wheel is moving through the air at double the relative speed. Example if you’re moving 20MPH the top of the tire is moving forward at 40MPH as it’s rotating forward and moving forward. I say this because the top of the MAG wheel is also moving "much faster" than your velocity thus helping the cooling at the top. The bottom has almost no wind speed to help cooling so calculating heat transfer and airflow characteristics is challenging.
Hi Justin, I race Electrathon and the more efficiently I can translate my electric energy into mechanical energy, the faster I can go. Am I correct in my understanding that assuming a fixed voltage, my motor will have an specific ideal current for maximum efficiency at that RPM? In other words, should I modulate my current based on RPM? Will this ideal current change with voltage? Will it change with motor temperature? Am I missing anything if I track RPM, Voltage and motor temperature when calculating the ideal current for that moment? What about load-going up or down a hill?
Your opening sentence is quite incorrect. It's not the efficiency of transfer that determines how fast you go, it's simply the rate of transfer (ie your power.) In something like an electrathon race, you should be much more concerned about your wh/km at any given point than your motor efficiency, which you can't really do anything about.
@@GrinTechnologies Justin, Thank you for your reply. I skipped a step in my first sentence which might make it an unclear over simplification. Let me try again. I am limited to 1000 Watt hours of energy in my battery. If I am able to operate my motor at 80% efficiency during the race, rather than 70%, then, I have 10% more mechanical energy to move my vehicle. With that extra mechanical energy, I will be able, during my 1 hour race, to propel my vehicle at a greater speed and thus cover more distance than if I did not have that extra mechanical energy. Is that not correct? I disagree that I cannot really do anything about my motor efficiency. For example, I can change my gearing (or wheel size for a hub motor) to operate the motor in a more efficient range. What I am asking about is varying my rate of transfer (power) to match the characteristics of the motor, to achieve the best amount of transfer (energy). I am doing this by varying my current based on RPM, but should I be considering voltage and motor temperature as well?
Well, on the bright side it's only a front hub motor and some people are pretty fixated on rear, so maybe it wouldn't have changed things for you ;-) There are always future ebikes you can build too!
@@GrinTechnologies Front is a no, rear yes. Mid drive expensive but less visible, so it's turned out ok as I can't fit a battery on a Kona stab, battery will be back packed. The Stab won't look like an ebike.
Thanks for the video, I had one question: If I want to drive around 32 km/h on an ebike, does it matter if I have a 500, 1000,1500 or 3000 watt (hub) motor for the range? (weight of bike+me is 120kg, battery is 60v 35ah) What would be the best?
The quick answer is no, it doesn't really matter. Your energy consumption will be about the same regardless of the motor model you ride on. For what is best, by what metric are you evaluating bestness? Which does it for the least $$, what does it at the highest efficiency?
I mean if you have dyno data it's super easy. Motor efficiency is motor output power over controller output power. Controller efficiency is controller output power over controller input power, but that would be harder to measure directly. You can easily estimate it by thermal means (measuring how hot the controller gets), or by knoweldge of the mosfet resistance and switching losses which you can see from a scope trace.
Eddie current? I used to be a great fan of Eddy Cochrane and Duane Eddie, but now I'm not so sure. . . Seriously this has been great fun. I now want to make a thin cylindrical gearless motor with statorade-cooled SILVER stator windings, with integral rotor and wheel/tyre. I know how mad that is.
The simulator most definitely includes the iron losses as well as copper losses. Was there a suggestion otherwise somewhere in the video? If you didn't include iron losses then the simulated efficiency would always approach close to 100% as the motor reached the unloaded speed (and copper losses drop to zero)
A speed throttle in your simulator would be AWESOME! I assume it would always be at "100%" so that at 15kph on the x-axis it applies enough torque to move the vehicle at 100% of 15kph = 15kph :-)
The thing is that doesn't really work with these plots when speed is on the X axis. you'd only have a single point of data to look at! Right now, if you just click "auto" throttle mode then you can click wherever you want on the graph to have adjust the throttle to deliver that particular speed, and the cursor will stay there if you do a simulation set to run some other plot (eg power consumption at constant speed as a function of %grade hill).
They say that Tesla Coep uses a supercomputer to work this stuff out, trying to follow this I;m not surprised! There are more, questions than answers, LOL!
Subject about copper losses. If you increase voltage and lower KV you should have lower copper losses and high torque. Especially if you wind the motor bifilar like Tesla's patent. Just pointing out that a higher voltage system is more efficient
That is not really true. If you increase the voltage and lower the KV you have exactly the same copper losses inside the motor, as the motor winding resistance increases to achieve the lower KV in a way that exactly cancels out any benefit of lower currents. It is only in the wiring outside from the motor controller to the motor where you would have lower losses in the higher voltage system, and that can easily be mitigated with heavier gauge wires and/or keeping the controller close to the motor so that the cable run there is short.
My old powabike brushed 36v wheel re-homed in a really nice bike and with a lithium 10s pack seems to use less current for the same speed as my mates modern Bafang geared 250 watt 36volt and definitely accelerates better - how come old brushed beats modern brushless ?????????
You can do that, but it's a fairly advanced DIY project to hook up a 2WD system to a factory ebike. This is covered in our multi-motor drive video. ruclips.net/video/Ub4EP2_mAds/видео.html
Love the new simulator Justin. I bet if Tesla knew about this they would want to pay you for it so it could be integrated into their range estimate models. You should reach out to them!
Your verry smart I'm trying to put together a beach cruiser e bike power and speed is what I want without spending big bucks recommend something please 60 mph at least w good torque last bike was a hiyabusa Brad sanders Phoenix AZ.
Dude every motor you desine you MUST TAKE IT OUT AND. TAKE IT TO THE LIMITS AND FIRST DO THE COMON TESTS THEN RUN IT TO OBLIVEAN of course you'll have recordings just like the Dine-o crap. Man I no what I'm talking about.
giant trance E bike (mid drive)......riding goldfeilds trail starting at bendigo victoria australia station.....on lowest asistance: 25.8 miles , 3196 foot hight gain....then same bike track charge but with traveling 20kmph on flat and atacking climbs::19.68 miles , 2169 foot hight gain....about 6 miles diferance and 1000 foot diferance...that is a big diferance...did the human work that much harder on the lowest setting? remember the human worked hard on bothe rides...after listening here i was hopeing the result would be other way round???..what looks good on paper does not always work in the real world...when you test regen..can you have a controll..a same bike same rider same battery and charge same motor same weather same corse but with free wheel?
"did the human work that much harder on the lowest setting?", it's not that they need to work harder, but they are working for longer time and so contribute a larger amount of energy even if the human power level is exactly the same. In your example the slower climb got 25% more range, and that's mostly because the rider was pedaling the bike for a 25% longer time period at the slower climbing speed. It's not because they were pedaling 25% harder. This is an important detail to properly understand.
@@GrinTechnologies yeah..i was amased at the diferance and was aware of the climb duration diferances..other things to consider are exelerations on tight tracks..momentum as you pointed out,and trying to keep the yamaha motor past peek power in terms of rpm to try balance losses whilst using gears and power asist buttons (your fingers and thumbs get very buisy)..i can send you the garmin tracking information if your interested...there is a bike packing ride race from the top to the bottom of australia in a copple of months if you want to come.
@@GrinTechnologies hey i just read your coment above again and it dawened on me that i gave you no time data..and you had based your coment on time periods...so i thaught id take a look at the run out of battery point on the shortest distance run and check times of bothe runns on the garmin data at the 19.6 mile mark...the eco setting time to the 19.6 mile mark is 1 hour 37 min..the 20kmph on the flat/atack the hills recomendations time to the same point 19.6 mile mark is 1 hour and 52 minutes...so your asumption that the eco setting human pedaled for a longer period of time is not correct.in fact it was the opposite by 15 minutes..... ' ...so to recap eco went quicker and futher than your use the least amount of battery power by climbing fast cruzeing slow recomendation...by 15 minutes and 1000foot and 6 miles.
If you want to no a thing you must get close and personal, in other words R AND D in other words you gotta blow some shit up man f..... the numbers. You gotta have bank !!!! Yup
You a smart dude I can tell. Don't get to raped up in the numbers. Get the creative side going towards COOLEING!!!!! THEN ALL THE HEET PROBLEMS GO AWAY !!!! Then you can hook up a real DRAG BIKE !!!! ILL BE YOUR RIDER.LOL
please make a plug and play 60 amp controller for the new Bafang Ultra G510 mid drive motor. this is the hottest selling mid drive that has no controller upgrades. LUNA Cycles has one but not for the Public market. I suspect the class #3-#4 speeds over 35 mph are a liability issue. the dude in England videos Suck and dont show any real way to make the Phaserunner an easy retro fit.
Excellent presentation Justin - thank you so much for going to this effort!
Running multiple simulations I learned quickly that to improve the torque in the upper motor RPM range like I want, I just need more voltage and there's pretty much no getting around it! I'll probably keep patiently waiting for battery improvements and stick with the 20S pack for the time being
*insert skeleton waiting meme*.
It was also really interesting to see how the torque to RPM performance mapped so similarly between different brands of hub motors. Some lingering misconceptions I had really fell away with your explanations and comparisons.
This was a very instructive video! Thanks for your efforts Justin, I really appreciate it. I wish your business and talented team catered a bit little more with e-bike products aimed at the 5KW-10KW "gray area" market that I like to play in, but totally understand all the reasons for not doing so.
You can get around it with a faster motor winding without a higher voltage battery, and you can somewhat get around it with field weakening which is increasingly a feature in better engineered controllers.
Anyways glad to hear that you have been learning from this video and good luck with your higher power endeavors !
Excellent video...for those wanting to maximize efficiency, the simplest way to make huge improvements is to simply slow down :).
Who would like for Grin to make their own mid-drive? A real competitor to the Cyc x1 Pro, just much quieter would be awesome! Maybe a larger motor and lower rpm and belt drive. Ideally with so much power that you don't need really need a fragile gear system. While I love their hub motors, hub motors have the problem of ruining ride quality because of unsprung weight. Also hub motors tend to look more illegal.
So you want everything that stresses the drivetrain more AND a belt drive. Why not just get used to walking with the setup you have? It'll be a lot cheaper.
Man, you speak my language! Explain why language is spelled the way it is. Concise fact based presentation with opinion towards overall cost. Some of us want to go as far as possible, many will come to that conclusion once they dive into the e-bike Blue Hole. Just the facts Jack!
Thanks, Richard
Thanks for a great presentation Justin.
I would like to request that some future presentation includes the topic of using a motor as a pedal-driven generator. I understand that this might be a bit of a special request so maybe it can be included in the regen video you are planning. Thank you!
This was an amazing presentation.
One factor that over rides all of the things you can do to increase efficiency/torque is COST. The mighty dollar makes the world go around just like electricity makes a motor go around :). Whether it is a higher grade of steel, more copper, tighter windings, etc...they all add cost so there is always a compromise of cost vs everything :). Justin...awesome job covering the variables, Thank You!
Batteries cost more than motors, and calling a taxi to drive you and your ebike home costs more than using the power you saved with a more efficient setup to drive yourself home.
Great video & tool you've made here! Wondering if the Regen explanation video ever got released? Browsed thru your channel & not seeing it
No, but will be doing a presentation on the topic this weekend at the bc bike show, and we'll try to record that and make an upload shortly after
A suggestion for increasing list of motors available to the motor simulator would be to have a how-to webpage or video explaining how people could measure this themselves and then crowd-source results. When two or more sources report essentially the same result that could be included on the list.
30:05 "The higher the RPM of the motor the more power it can generate and --more torque it can produce--"
Is the torque part misspoken, because you forgot to add the "efficiently" part to the end of the sentence when you said it? The powerpoint page does have the "efficient torque production" written.
I'm just getting a bit confused, as is my understanding that RPM doesn't affect how much torque the motor (PM-motors) can produce to an extent (losses), but does effect how efficiently it can produce it. Isn't stall torque the greatest amount of torque the motor can produce and I don't think it should be able to increase if you increase the RPM? I think there was a later part where you said the quoted sentence again, so I'm just asking for a clarification.
I'm an electronics engineer who does electric skateboard building as a hobby and I've been logging and monitoring my board's performance and efficiency on my rides (as you do as an engineer, as you said :D)
EDIT: Otherwise an excellent presentation and lots of great information!
You are 100% correct here so thanks for pointing this out. I should have said "power and EFFICIENT torque production" as is written on the slide. The motor can still produce high torques at low RPMs, but the efficiency of the motor is much lower in this scenario than when it produces that same torque at higher RPMs.
Stall torque is mostly determined by the battery or phase current limits of the motor controller, it's not a motor characteristic but a system characteristic. If you are phase current limited by the controller, then the torque is totally flat and independent of RPM up until the speed where your you become either battery current limited or voltage limited. All of this is modeled on our motor simulator app (including a number of skateboard hub motors) so you can see the effect of different phase or battery current limits on the torque/speed line.
Is the equation at 1:00:08 correct? I am just slightly confused how Imotor=(Vmotor-Kw)/R
Say if there’s a 72v battery back
Vmotor= 71.6v
K = 12rpm/volt
RPM = 750 ~ 75rad/sec
71.6v-(75rad / sec * 12 rpm / volt) = negative number
What am I doing wrong?
How do you find Vmotor?
If you have Kv in RPM/V, then either you don't convert to rad/sec as you are using units of revolutions per minute. If you did want to convert into rad/sec, then 12 rpm/V = 1.257 Rad/sec/volt, = 0.796 V/rad/sec (which is the units of Kv in the equation)
Vmotor is the voltage that the controller is sending to the motor (ie battery voltage times the duty cycle). Kw is the back-emf voltage of the motor. If it's 12 rpm/V, and your motor is spinning at 300 rpm, then Kw = 300 rpm / 12 rpm/V = 25V. Or if you are in rad/sec mode, 0.796 V/rad/sec * 31.42 rad/sec = 25V
If you have a 72V battery pack, I can guarantee you that your motor controller is not going to be supplying 71.6V to the motor if the motor's back-emf voltage is just 25V, it would be limiting it based on either the phase current limit of battery current limits programmed into the controller.
Thank you so much that makes perfect sense!
Amazing prezentation, Justin!
Great job hitting marketing bullshit with solid physics!
Would it be worth it if they made finer laminations than 0.35mm that they are now?
Only in cases of motors with very high eRPMs where eddie losses are still significant even with 0.35mm stators. There are very much diminishing returns with thinner lams if eddie current losses are not a dominant part of the core heating. We have some MAC / GMAC motor samples with 0.2mm stators for evaluation to see if it's worth it or not.
@@GrinTechnologies Hi, thanks for the informative and detailed video! Is there any update on 0.2mm vs 0.35mm vs 5mm laminations?
good job..im glad you seperated eficiency from economy..i would have liked to be shown steeper hills and where hub motors start to sigh off/stall and how long a midrive with gears can hang in there....you shed a bit of light on my long time question "how fast to climb?" (but only for 6% grade) ... for my off road long distance bike packing/racing application i had come to the conclusion that mid drive was the only way that will work...this presentation has given me more to think about but as much as id like a DD hub motor to work in my application i have a feeling it wont work...having said that i might be able to mount a motor forward of the rear wheel and experiment with diferent gearing between rear wheel and motor only...you point out on climbs go fast 15kmph and cruze flat ground slow 20kmph (6% grade only) might be workable ish..off road climbing a steep hill or tight mountain track,15kkmph is very fast and 20kkmph out on a gravel or sealed road is slow ish....this application is asking for 2 gears for the motor to wheel only...i like that you pointed out with a mid drive to keep the human and motor sincronised in thair best rpm ....this suggest if building for a mid drive one strong ish assist level only so that you use that one assist level only and all the time with maybe a higher help level when the only other option is walk.but go slow on the flat....interesting that the 25kmph limited comercial bikes can climb fast and not go fast on the flat.....what you are pointing at for economy and using an electric motor looks very much like a single speed human gearing with a direct drive hub motor mounted forward of the wheel and geared lower...ooo we love simplicity:).....you nearly answered another long time question i have....how much energy are bl controllers using?..and can a brushed motor be more economical at our low motor speeds with out a controller or pwm ?
Hey Russel, hopefully if you watch and follow a bit more closely you'll see how you can replicate exactly the same kind of simulation runs that I did to quantify how things will be at even different grades or riding scenarios. As long as the really steep hills aren't too long then usually a powerful hub motor (like the GMAC or RH212) will be totally fine with this usage, but if you have looong steep hills to climb you may need to budget cooldown breaks for the motor otherwise they can go into thermal rollback.
Brushless motors are generally cheaper than brushed motors for the same power and torque capabilities, so they are the more economical choice. A DC motor without any motor controller at all is not a very good idea and not very useful as you couldn't modulate the power independently of speed or use regenerative braking.
@@GrinTechnologiesyou say in relation to no controller. "you couldn't modulate the power independently of speed" there are ways to alter voltage with out a controller and if you run the human and motor through the gears you can modulate the power independantly of the speed or we can say that backwards. you can modulate the speed independantly of the power or we can say we can shuffle torqe power and speed with gears...however your talk hints that for economy for a mid drive we should be at an rpm that balences losses and matches the human rpm and for hub motor economy our speed need only change 5kmph (6% grade)..a controller would help(depending on its energy consumption) however one voltage/rpm would also work up untill a stall grade % ..rpm's past the loss balance rpm..althogh this goes biast toward the magnet losses it uses less and less battery power untill we get to zero power used/ no load ...then its human or gravity overcoming all drag......if a free wheel is used here stored energy in altitude can be used to coast if the down hill gets steeper...if no free wheel is used then you are driving the motor with gravity and this will create drag and electriserty....you say " can not use regenerative braking" i think you ment to say "can not use proportinal regen"?...you also say "Brushless motors are generally cheaper than brushed motors for the same power and torque capabilities, so they are the more economical choice." a 500 to 1000w brushed DC motor with out controller is $25 to $50 usd ......heres a question iv had for a while...how much power do BLDC motor controllers use specificaly in our aplications?
Temp vs efficiency: I read that when heated magnets produce weaker force, thus affecting motor performance.
Is there any approx multiplier to estimate motor efficiency at different temperatures?
That is a superb question that I didn't get into at all in this presentation, but is totally true and yes at some temperature the magnets become weaker too which further degrades performances. You can see how the torque per amp starts to roll off here when the stator gets over 130oC
endless-sphere.com/forums/viewtopic.php?p=218321#p218321
However, didn't have a temperature probe on the actual magnets to see what their temperature was at, and obviously different grade magnets are affected differently by elevated temperatures. In outrunner motors, the magnets can still be quite cool even when the copper is hot, but in an inrunner motor the magnet temperatures would get close to the copper temps, and this could further degrade performance in a measurable way. It's not modeled on our simulator though, only the increased winding resistance is there.
Thank you for great video! Very useful information. Very interested into section "optimal efficiency RPM vs Power", and my question here is if there are 2 identical motors but with different kv parameters, would they have different graphics or same? So if I need for example 5000w and I have motor with 8kv or 12 kv, what motor is better for 180rpm ?
Identical motors will be identical. Doesn't matter what the Kv is. At 5000 W and 180 RPM both motors provide the same torque. Both will perform exactly the same.
44:45 in the video
In addition to the correct comment here by difflocktwo, I did want to add that you will see a small difference in efficiency with the motor simulator tool with the two different windings, but that is because of higher controller losses in the faster motor wind. If you set the controller resistance to 0 ohms to only look at motor efficiency, then it works out to be the same.
@@GrinTechnologies If so, is there any reason to use low kv motor? Especially if the controller still can provide phase amps for high kv motor.
For example, I have 120 A max phase current but use only 50 A and top speed is 42 km/h. I can swap motor for higher kv (double it) and get a boost to speed (even for a short time due to heating). Any downsides?
Thank you very much for the video, it made a lot of things clear to me!
However, one point is missing:
5 km/h is not a realistic speed. Then you can dismount and activate the push assist and be MUCH more efficient ;-)
You said the trip simulator shows the battery efficiency and the motor simulator the controller efficiency. Do you multiply them to get the total system efficiency?
Is there any way to record real time data from a trip so that the data could be run thru the simulator to discover ways to increase efficiency if that trip is repeated. For example - say you do a repeated trip daily such as a commute to and from work. It would be very useful to analyze the parameters of your trip to see how changes to throttle use would effect battery usage or compare different routes to see which is more energy efficient. Would also be interesting to have a function to analyze a long trip to see what the power requirements would be if you do the reverse trip back home. Not sure how this could be implemented but just wondered if you have given any thought to try to develop this capability?
ebikes.ca/tools/trip-simulator.html
Input type change from "manual plot" to "google maps"
Hi, I hope You will do that kind of deep dive presentation again soon.
Best video of motors out there! Some are to general... Im designing a hub motor for a small vehicle, the weight of the motor is 170g and the gear ratio to the road is around 0,7 (direct drive). I have two of them so 300g, the car weight is 2.3 kg. But it has not much torque... Is there a scaling issue of motors?
Certainly small motors usually have worse efficiency and power density than larger motors, but at 170g you should still be able to get enough power to move half of 2.3kg vehicle quite well.
How much of the measured hysteresis losses are actually mechanical losses ( friction in the gearing, bearings, etc. ) ?
Excellent presentation. Does anybody know why there isn't more axial pancake design motors made, since they are more efficient and powerfull being smaller and lighter? I feel there is a market for this motor because of all the benefits
I can tell you that this question comes up all the time. I think most people who actually go about seriously looking into making one realize that the mechanical challenges with unbalanced forces required for a reliable axial flux motor in this power and size class outweigh the potential benefits. But that's not to say it can't be done and we would certainly welcome anyone overcoming those challenges and breaking new ground here!
When somone is asking for best efficiency on hills, is more like:
- "I like riding fast, but also would like to do it at optimal efficiency of motor".
Normally I ride MTB 25-30km/h flat and 15-20 on hills.
Upgrading to ebike I would expect around 35 flat.
So now is question what is optimal speed for motor efficiency on hills? Using as a reference point speed I'm cruising on flats.
Because biking is mostly about physcial activity for me, I can do a little burnout in my legs on hills.
So I can pedal 700W through 40s segment of hill. I dont care about aerodynamic drag.
I kinda forgot what I really wanted to ask about.
But mostly about motor efficiency and power distribution legs/motor.
For the most part, as long as the motor has sufficient torque to go up the hill at a decently fast speed is best to just key going fast. Let speeds have similar copper losses but stretched out over a longer time period so more total heat is generated.
Humans will slow down to rather pathetic speeds on a hill climb, like 5-10kph. They're is no advantage to emulating that if you have a hub motor.
So do motor controllers with advanced features like FOC change the efficacy or is it like field weakening and just allows the motor to operate with a larger envelope. My non learned understanding of foc is its like field weakening in that it plays with the magnetic fields but with real maths to get the effects of optimal magnetic interaction for smooth mechanical force and in turn power efficacy.
In practical steady state terms, a field oriented controller behaves just like a sinewave controller but with always optimized timing advance. You do get better efficiency from the motor (by a couple percent) than you have from a trapezoidal drive, and you also have a faster increase in torque as the motor is loaded and slows down.
All I know is computer power supply. Peak efficiency would be around 50-80% of load and drop off any lower or higher than that. Does hub motors have same effect?
Not really. There is no analogy in a computer power supply to the widely varying rpm at which motors operate. Watch and follow the video if you want to properly understand what determines motor efficiency
Thank you Justin, great presentation! It is really DIP dive into this huge subject.
I am still looking for the best answer to this common question: for a given DD motor/battery/controller which is the ideal 'uphill' speed to minimize overheat AND consumption?
If the rider is pedaling, then the least heat and least consumption is climbing the hill quite slowly. Then the legs to most of the work and the battery/motor less so. But if the rider is NOT pedaling or only pedaling with low effort, then you use exactly the process that I demonstrated in the video to make a simuilation set that plots the result. I was surprised to see that over a range of different motors and grade hills it almost always fell in the 15-20kph realm for lowest consumption. So that would be a simple answer if you don't want to get into details with a commoner.
@@GrinTechnologies Thanks, I'll keep in mind these indications. May be one day I'll invest half a day to perform some 'real life tests' with my actual setup. My power meter should also allow to derive more precise figures for each data set.
Is there a ''fast'' way to plot efficiency 3d plot ''island'' that we can see for many motors ?
With a vehicule power requirement curve over it.
Would be usefull fo hubmotors,
Thanks
I don't know enough words in english to appreciate this presentation. And it will be 101% awasome if you record it in 1080p. Some text on screenshots isn't readable.
thank you! great practical guide!
Great stuff 👍👍
I have a Walmart 20" Kent torpedo bike 24volt and 180 watt hub motor without gearing.i would like to be able to make a 25 mile trip under power .it has a 5.4 amp hour battery can I use lead acid to work? What battery is cheap to achieve my goal
You can use lead acid, but a 24V 5.4Ah lead battery is just tiny and no way it would do 25 miles. Due to the peukert effect that's well under 100 Wh. You should be looking at more like 15-20 Ah with a 24V lead acid system for that kind of range.
Sir, I'm very much interested in your product. But I have a small dought to clarify, the thing is how a regenerative brakes offers constant current and constant voltage, although it is a highly complicated question or it is ur business secret. Can I Hook up a 60v ac on the motor phases to charge my battery? If yes, at how much is the maximum power I can get and is regenerative braking causes heating up of controller. That's all in my mind, I wish to have answers ASAP to buy your convenient products that are made for the performance. Thank you, sir for your time.
I'm trying to run a phase check program on a sabvoton 72100 controller and a qs205 hub. They did not send the short little stub electrical fitting that plugs into the display cable to run the hall sensor test. Any suggestions? Do you have a tutorial vid. on programming the two together?
We don't deal with Sabvoton controllers unfortunately.
If I lower my amps from the controller will it increase my range. Or could I accomplish the same thing by governing my speed? Or does either one even matter? Right now I have an 48v 24ah battery, a 40 amp controller, and a 3540 crystalyte hub motor and with throttle only I'm only getting about 30 miles. Is that normal? Would I get more range if I lower the amps from the controller?
Hi Randy, you get more range when you use less power from the battery, it's as simple as that. It doesn't matter if you do that by reducing the current limit of the controller or setting up a speed limit, but those two methods change how that reduced power is distributed along the ride. Lower current limit means you'll have less power climbing hills, accelerating and such but your top end speed is unaffected. A speed limit won't affect your low end power and torque but it will of course reduce your power once your are up to speed.
And 30 miles on a 1.1 kwhr battery is typical of a fast and power hungry setup like that. At more typical power levels and speeds your have 60-70 mile range.
At 1:20:28 With increasing speed I see you plotted a sharp climb in Motor Temp with increased speed? Sure increased wattage will raise the temperature but are you even factoring the massively increased "air cooling" to the hub motor as the speed increases? Think of it as a fan blowing on the wheel and hub. The faster you go the higher CFM of the fan to cool the motor. Also have you charted hub motor cooling with speed when using an "Aluminum mag Wheel" instead of spokes? Mag wheels have huge advantages for Ebikes as they act as a giant air cooled heatsink. Increased Air Speed helps cool the motor so are your motor temperate plots even accounting for air cooling and MAG wheels?
If you make a simulation don’t forget with the MAG wheel rotating the bottom tire that touches the ground has ZERO speed. While the top of the wheel is moving through the air at double the relative speed. Example if you’re moving 20MPH the top of the tire is moving forward at 40MPH as it’s rotating forward and moving forward. I say this because the top of the MAG wheel is also moving "much faster" than your velocity thus helping the cooling at the top. The bottom has almost no wind speed to help cooling so calculating heat transfer and airflow characteristics is challenging.
Hi Justin, I race Electrathon and the more efficiently I can translate my electric energy into mechanical energy, the faster I can go. Am I correct in my understanding that assuming a fixed voltage, my motor will have an specific ideal current for maximum efficiency at that RPM? In other words, should I modulate my current based on RPM? Will this ideal current change with voltage? Will it change with motor temperature? Am I missing anything if I track RPM, Voltage and motor temperature when calculating the ideal current for that moment? What about load-going up or down a hill?
Your opening sentence is quite incorrect. It's not the efficiency of transfer that determines how fast you go, it's simply the rate of transfer (ie your power.) In something like an electrathon race, you should be much more concerned about your wh/km at any given point than your motor efficiency, which you can't really do anything about.
@@GrinTechnologies Justin, Thank you for your reply. I skipped a step in my first sentence which might make it an unclear over simplification. Let me try again. I am limited to 1000 Watt hours of energy in my battery. If I am able to operate my motor at 80% efficiency during the race, rather than 70%, then, I have 10% more mechanical energy to move my vehicle. With that extra mechanical energy, I will be able, during my 1 hour race, to propel my vehicle at a greater speed and thus cover more distance than if I did not have that extra mechanical energy. Is that not correct? I disagree that I cannot really do anything about my motor efficiency. For example, I can change my gearing (or wheel size for a hub motor) to operate the motor in a more efficient range. What I am asking about is varying my rate of transfer (power) to match the characteristics of the motor, to achieve the best amount of transfer (energy). I am doing this by varying my current based on RPM, but should I be considering voltage and motor temperature as well?
I bought a Bafang BBSHD mid drive yesterday because I couldn't find a bolt thru hub.
Today I see your All-axle hub motor video. :(
Well, on the bright side it's only a front hub motor and some people are pretty fixated on rear, so maybe it wouldn't have changed things for you ;-) There are always future ebikes you can build too!
@@GrinTechnologies Front is a no, rear yes. Mid drive expensive but less visible, so it's turned out ok as I can't fit a battery on a Kona stab, battery will be back packed. The Stab won't look like an ebike.
@@gteaz Backpacking a battery...ouf. That's gonna suck hard if you dump it.
@@fun_ghoul The Lithium is wrapped up in foam.
@@gteaz That just makes the lump that will break your back bigger.
Thanks for the video, I had one question:
If I want to drive around 32 km/h on an ebike, does it matter if I have a 500, 1000,1500 or 3000 watt (hub) motor for the range? (weight of bike+me is 120kg, battery is 60v 35ah) What would be the best?
The quick answer is no, it doesn't really matter. Your energy consumption will be about the same regardless of the motor model you ride on.
For what is best, by what metric are you evaluating bestness? Which does it for the least $$, what does it at the highest efficiency?
How do I Calculate Motor Efficiency and Controller Efficiency after collecting Dyno Data?
I am unable to calculate the AC Power output power coming from the Controller.
I mean if you have dyno data it's super easy. Motor efficiency is motor output power over controller output power. Controller efficiency is controller output power over controller input power, but that would be harder to measure directly. You can easily estimate it by thermal means (measuring how hot the controller gets), or by knoweldge of the mosfet resistance and switching losses which you can see from a scope trace.
What about a cvt for regen?
Eddie current? I used to be a great fan of Eddy Cochrane and Duane Eddie, but now I'm not so sure. . . Seriously this has been great fun. I now want to make a thin cylindrical gearless motor with statorade-cooled SILVER stator windings, with integral rotor and wheel/tyre. I know how mad that is.
Does motor simulator really ignore iron losses, I'm planning to convert my cheap dd motor to mid drive, and I hope I'm not getting bamboozled...
The simulator most definitely includes the iron losses as well as copper losses. Was there a suggestion otherwise somewhere in the video? If you didn't include iron losses then the simulated efficiency would always approach close to 100% as the motor reached the unloaded speed (and copper losses drop to zero)
A speed throttle in your simulator would be AWESOME! I assume it would always be at "100%" so that at 15kph on the x-axis it applies enough torque to move the vehicle at 100% of 15kph = 15kph :-)
The thing is that doesn't really work with these plots when speed is on the X axis. you'd only have a single point of data to look at! Right now, if you just click "auto" throttle mode then you can click wherever you want on the graph to have adjust the throttle to deliver that particular speed, and the cursor will stay there if you do a simulation set to run some other plot (eg power consumption at constant speed as a function of %grade hill).
They say that Tesla Coep uses a supercomputer to work this stuff out, trying to follow this I;m not surprised!
There are more, questions than answers, LOL!
Subject about copper losses. If you increase voltage and lower KV you should have lower copper losses and high torque. Especially if you wind the motor bifilar like Tesla's patent. Just pointing out that a higher voltage system is more efficient
That is not really true. If you increase the voltage and lower the KV you have exactly the same copper losses inside the motor, as the motor winding resistance increases to achieve the lower KV in a way that exactly cancels out any benefit of lower currents.
It is only in the wiring outside from the motor controller to the motor where you would have lower losses in the higher voltage system, and that can easily be mitigated with heavier gauge wires and/or keeping the controller close to the motor so that the cable run there is short.
You are good with your voice sir
My old powabike brushed 36v wheel re-homed in a really nice bike and with a lithium 10s pack seems to use less current for the same speed as my mates modern Bafang geared 250 watt 36volt and definitely accelerates better - how come old brushed beats modern brushless ?????????
Brushed vs brushless has almost no effect on motor efficiency. What matters are winding resistance and core losses, not how current is commutated.
I have a Rad mini fat bike I live up a steep hill I need more power I want to add a hub motor to the front wheel
You can do that, but it's a fairly advanced DIY project to hook up a 2WD system to a factory ebike. This is covered in our multi-motor drive video. ruclips.net/video/Ub4EP2_mAds/видео.html
Excellent
Love the new simulator Justin. I bet if Tesla knew about this they would want to pay you for it so it could be integrated into their range estimate models. You should reach out to them!
😍😍😍😍😍😍😍😍😍 . now i just need 2 of your controllers lol. Dreams
Very interesting
Your verry smart I'm trying to put together a beach cruiser e bike power and speed is what I want without spending big bucks recommend something please 60 mph at least w good torque last bike was a hiyabusa Brad sanders Phoenix AZ.
Are you you live in right now
Flat track racing! Electric! It's coming man !!!! You could be the guy that came out with the MOTER THAT DID IT. YUP
'Eddie' Core Loss! (I think it's spelled Eddy, as in, 'Eddy Currents')
Sorry if I sound pedantic, just trying to be helpful.
Whoopsy, thank you for catching that! A typo indeed.
Constant torque should probably be the default view in the simulator.
Yes
Seems like Toyota solved this with the Prius drive system with two motors connected via a planetary gear system.
yes
i can hear you
Dude every motor you desine you MUST TAKE IT OUT AND. TAKE IT TO THE LIMITS AND FIRST DO THE COMON TESTS THEN RUN IT TO OBLIVEAN of course you'll have recordings just like the Dine-o crap. Man I no what I'm talking about.
Good in florida
Love good
giant trance E bike (mid drive)......riding goldfeilds trail starting at bendigo victoria australia station.....on lowest asistance: 25.8 miles , 3196 foot hight gain....then same bike track charge but with traveling 20kmph on flat and atacking climbs::19.68 miles , 2169 foot hight gain....about 6 miles diferance and 1000 foot diferance...that is a big diferance...did the human work that much harder on the lowest setting? remember the human worked hard on bothe rides...after listening here i was hopeing the result would be other way round???..what looks good on paper does not always work in the real world...when you test regen..can you have a controll..a same bike same rider same battery and charge same motor same weather same corse but with free wheel?
"did the human work that much harder on the lowest setting?", it's not that they need to work harder, but they are working for longer time and so contribute a larger amount of energy even if the human power level is exactly the same. In your example the slower climb got 25% more range, and that's mostly because the rider was pedaling the bike for a 25% longer time period at the slower climbing speed. It's not because they were pedaling 25% harder. This is an important detail to properly understand.
@@GrinTechnologies yeah..i was amased at the diferance and was aware of the climb duration diferances..other things to consider are exelerations on tight tracks..momentum as you pointed out,and trying to keep the yamaha motor past peek power in terms of rpm to try balance losses whilst using gears and power asist buttons (your fingers and thumbs get very buisy)..i can send you the garmin tracking information if your interested...there is a bike packing ride race from the top to the bottom of australia in a copple of months if you want to come.
@@GrinTechnologies hey i just read your coment above again and it dawened on me that i gave you no time data..and you had based your coment on time periods...so i thaught id take a look at the run out of battery point on the shortest distance run and check times of bothe runns on the garmin data at the 19.6 mile mark...the eco setting time to the 19.6 mile mark is 1 hour 37 min..the 20kmph on the flat/atack the hills recomendations time to the same point 19.6 mile mark is 1 hour and 52 minutes...so your asumption that the eco setting human pedaled for a longer period of time is not correct.in fact it was the opposite by 15 minutes.....
' ...so to recap eco went quicker and futher than your use the least amount of battery power by climbing fast cruzeing slow recomendation...by 15 minutes and 1000foot and 6 miles.
Na AT THAT SPEED THE AIR +CAWLING NO PROBLEM MAN!!!!! COMMON
To are good
Ok
Live good
If you want to no a thing you must get close and personal, in other words R AND D in other words you gotta blow some shit up man f..... the numbers. You gotta have bank !!!! Yup
You a smart dude I can tell. Don't get to raped up in the numbers. Get the creative side going towards COOLEING!!!!! THEN ALL THE HEET PROBLEMS GO AWAY !!!! Then you can hook up a real DRAG BIKE !!!! ILL BE YOUR RIDER.LOL
please make a plug and play 60 amp controller for the new Bafang Ultra G510 mid drive motor. this is the hottest selling mid drive that has no controller upgrades. LUNA Cycles has one but not for the Public market.
I suspect the class #3-#4 speeds over 35 mph are a liability issue.
the dude in England videos Suck and dont show any real way to make the Phaserunner an easy retro fit.
I can make you famous
Shitty Customer Response
Bothe are a rip of !! For the efficiency. Regular people can't afford it!!! Gas engines will do it for penny's.
Yes
Yes