Again...3T, 4T, 5T, 6T difference

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Sparfuchs   100 W

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Again...3T, 4T, 5T, 6T difference

Post by Sparfuchs » Nov 22 2020 4:04pm

Hello my Friends,
Please just post a link to a thread or a website that answers my questions if thre is one :)

So my question: For my first project I'd like to build a diy e mtb and assuming the qs 205 v3 is the best powerfull option if i don't want to have the weight and size of a qs 273 right ? Or is the mxus 5k a better option ?
At the moment i have a 20s6p pack with samsung 35e cells but i'm willing to get a "better" one next year if needed.
So i think the turn counts mean its a balace between volts and amps to get to the same torque of the different turn counts right ? But what does that mean in my case if i want a motor that has a lot of acceleration power when starting and maybe even does powerwheelies ? ;)
I prefer acceleration but also don't want it to have too low high speed. For now i'll run it with my 20s6s batterie pack but ill build a new one with a stronger frame and bigger battery one day and want to use the same motor i'm planing to buy now.
And any recommends on a controller below 500 usd that has a good performance? Is the unlocked sabvoton 72150 a idea?
So many questions... Sorry.. But again:

Qs205v3 or mxus 5k turbo ...or something better avaleable ?

"Best" turn count and right batterie for insane acceloration in lower speed ?

Good controller to use for my set below 500 usd?

Thanks a lot for your help
Sparfuchs

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Re: Again...3T, 4T, 5T, 6T difference

Post by neptronix » Nov 22 2020 4:11pm

important question...
..what top speed are you looking for?

..because what top speed you want will influence what winding is best for you.
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Re: Again...3T, 4T, 5T, 6T difference

Post by minde28383 » Nov 22 2020 7:09pm

probably qs 205 3kw.

Regarding winding. There is no best option. All options are ok and great.
More Turns, more it heats up with the same amps but more torque from starts.
Less Turns more dynamic in higher speed but be prepared to get new battery.

Also dynamic depends on what rim size you get.

If you will get fast winding your will have less dynamic ride than you would have with 5T or 6T.
If you get slow motor 5t or 6t you will get better dynamic with you weak battery.

Unlocked is not necessary if getting 5t or 6t. But some use 200a on 5t but it's insane torque and fast motor heat up, therefore small wheel, ferrofluid, heat sinks prefered.

More turns, more resistance, more torque per amp. You get more torque but need to cool down motor.

If want wheeles than 5t, especially with your battery you will be disappointed with faster motor. If you get better battery than maybe 4t, but if you really require wheelies than 5t (6t if wheel size is very big).
But overall 4t is great, 3.5t is great too; need stronger battery.
with ~20s, field weakening:
5t - 85 kmh
4t,3.5 105kmh

with no field weakening slower by ~15 ~20 km/h.

keep in mind less speed when battery gets discharged or in you case will also sag (drop voltage on high discharge) because only 6 paralel. Smaller wheel also help for wheelies and motor heats less , for ex 17'' rim or even 16''.

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Re: Again...3T, 4T, 5T, 6T difference

Post by Sparfuchs » Nov 23 2020 3:19am

Wow, i really love this forum for its fast and good answers. Thanks a lot my friends. :bigthumb:
neptronix wrote:
Nov 22 2020 4:11pm
important question...
..what top speed are you looking for?

..because what top speed you want will influence what winding is best for you.
Thanks for responding :)
Of course i want as much top speed as possible but i also know that more top speed also means lower torque in lower speed spectrum right ?
The most acceleration/torque i'd like to have between 0 and 40 kph. What do you think is a possible option with a 18 inch motorbike rim ?
minde28383 wrote:
Nov 22 2020 7:09pm
probably qs 205 3kw.

Regarding winding. There is no best option. All options are ok and great.
More Turns, more it heats up with the same amps but more torque from starts.
Less Turns more dynamic in higher speed but be prepared to get new battery.

Also dynamic depends on what rim size you get.

If you will get fast winding your will have less dynamic ride than you would have with 5T or 6T.
If you get slow motor 5t or 6t you will get better dynamic with you weak battery.

Unlocked is not necessary if getting 5t or 6t. But some use 200a on 5t but it's insane torque and fast motor heat up, therefore small wheel, ferrofluid, heat sinks prefered.

More turns, more resistance, more torque per amp. You get more torque but need to cool down motor.

If want wheeles than 5t, especially with your battery you will be disappointed with faster motor. If you get better battery than maybe 4t, but if you really require wheelies than 5t (6t if wheel size is very big).
But overall 4t is great, 3.5t is great too; need stronger battery.
with ~20s, field weakening:
5t - 85 kmh
4t,3.5 105kmh

with no field weakening slower by ~15 ~20 km/h.

keep in mind less speed when battery gets discharged or in you case will also sag (drop voltage on high discharge) because only 6 paralel. Smaller wheel also help for wheelies and motor heats less , for ex 17'' rim or even 16''.
Thank you very much minde28383 for your great answer.
Theoretically i could build any battery pack i want. But the question is how many cells/total weight i want to use and how i will balance paralell and seriell right ? So if i'd choose the motor first and build the "perfect" battery afterword... The 5T/ 6T is still the best choice if i want insane acceleration at the start right ? And it would also mean that i could use more of the cells in serial with same weight and better range right ?

Using ferrofluid or hub sinks would be also a option for me if its needed :)

But whats the think with the field weakning?
What is important to know about that ?

Thank you so much for helping

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Re: Again...3T, 4T, 5T, 6T difference

Post by minde28383 » Nov 23 2020 8:18am

18'' is ok. Kinda big diameter especially with 3.0 tire but anyways small compared to 26 bicycle wheel.
18'' ok for 5t but for faster motor maybe 17'' or even 16'', but most people stick to bigger wheels for better looks, that is why mass sold ebikes have bigger wheels . Smaller wheel better acceleration but less max speed.

Different battery and controller will make the same motor to perform differently.
People might achieve the same results with different motors by using different batteries, controllers, wheels sizes. ebike weihts, riding styles, cooling, no cooling, riding few km and resting, aiming to ride for longer distances.
Nevertheless here are some thoughts:

For faster motor you need more amps from starts to achieve the same good performance ie wheelies from 0 to ~35kmh (maybe up to 40kmh). Because you need more amps for faster motor you might need bigger better battery (but not necessarily because you might have the same amount of cells but with higher discharge rate, better mere expensive cells).
Overall it is likely that with faster motor you might need heavier battery by ~30%. We are talking about 300pcs-400pcs , 20s15p - 20s20p, it is 15kg - 20kg battery pack, or more or less, depends on cells and desired battery capacity.
With fast motor you will shed lots of amps from stand still to achieve those wheelies. But it does not mean that you can't shed lots of amps with slower motor. It all depends on controller settings, ebike weight, acceleration time...
Max speed will be ~90kmh without field weakening


For slower motor theoretically you might have less cells overall 20s10p 20s-15p, 200pcs-300pcs because (but it all depends on cells) to achieve the same required wheelies from 0 to 40kmh, but you still need good battery.

If you plan to ride in forest 70% forest than 5t.
If you plan to ride 70% road than 4t or 3.5t.

We are talking about 20S battery (84v). With different voltages you have different performance.
you can still ride in forest with 4t and 3.5t but in slow speeds 0-30kmh you will shed many amps when full throttle. So for forest fast motor is less suitable.

OVS / field weakening.
This is electronic feature which enables some additional speed by additional energy expense. For example 5t can reach 70kmh but with fw enabled - 90khm.
fw is different on different controllers. On cheap controllers fw heats up motor. So you can reach higher speed but shed more amps and make lots of heat. For short time it is ok but soon you heat up motor. Expensive controller have better fw and heats up motor less.

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Re: Again...3T, 4T, 5T, 6T difference

Post by pwd » Nov 23 2020 8:47am

minde28383 wrote:
Nov 22 2020 7:09pm
...
If you will get fast winding your will have less dynamic ride than you would have with 5T or 6T.
If you get slow motor 5t or 6t you will get better dynamic with you weak battery.
...
As far as I understand and having read though the "myth" crushing threads; a faster wind or low turn count doesn't demand more current from the battery pack. It demands more phase current from the controller; which is done with the same input (battery) power.
Commuter/Street Build viewtopic.php?f=6&t=98286:
Rocky Mountain Element
Magic Pie 4 front + Leafmotor 1500 rear w/ Infineon 4 Clone @ 200A phase
Samsung 40T 14S7P

Offroad Build viewtopic.php?f=6&t=102195:
2019 Rocky Mountain Blizzard 20
Cyclone "3kw" 13T motor to 36T chain ring then 32T chain ring to 11T-46T Cassette @ 100A phase
em3ev 14S5P 30Q or 14S6P 25R pack

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Re: Again...3T, 4T, 5T, 6T difference

Post by minde28383 » Nov 23 2020 9:09am

pwd wrote:
Nov 23 2020 8:47am
minde28383 wrote:
Nov 22 2020 7:09pm
...
If you will get fast winding your will have less dynamic ride than you would have with 5T or 6T.
If you get slow motor 5t or 6t you will get better dynamic with you weak battery.
...
As far as I understand and having read though the "myth" crushing threads; a faster wind or low turn count doesn't demand more current from the battery pack. It demands more phase current from the controller; which is done with the same input (battery) power.
Nop, because one lives in material world with predetermined conditions like readily available controllers, popular battery voltages.
These myth busters never tried any of these motors but have pencil and paper and few physics books.

by post edit I extend myself little bit more. What I mean by 'predetermined'. We have readily available controllers and they perform as they do perform and result is that slower motor is more dynamic in slower speeds. Vast majority is using Sabvoton and Kelly with 3kw hubs. We are talking about 350a and 300a phase.
Also worth mentioning that battery amps is also the factor, not only phase current as you mentioned. Talking about slow speeds and starting from stand still. With fast wound motor you draw more amps from battery because you set more amps on your controller to achieve the same expected performance from stand still.

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Re: Again...3T, 4T, 5T, 6T difference

Post by pwd » Nov 23 2020 9:56am

minde28383 wrote:
Nov 23 2020 9:09am
pwd wrote:
Nov 23 2020 8:47am
minde28383 wrote:
Nov 22 2020 7:09pm
...
If you will get fast winding your will have less dynamic ride than you would have with 5T or 6T.
If you get slow motor 5t or 6t you will get better dynamic with you weak battery.
...
As far as I understand and having read though the "myth" crushing threads; a faster wind or low turn count doesn't demand more current from the battery pack. It demands more phase current from the controller; which is done with the same input (battery) power.
Nop, because one lives in material world with predetermined conditions like readily available controllers, popular battery voltages.
These myth busters never tried any of these motors but have pencil and paper and few physics books.

by post edit I extend myself little bit more. What I mean by 'predetermined'. We have readily available controllers and they perform as they do perform and result is that slower motor is more dynamic in slower speeds. Vast majority is using Sabvoton and Kelly with 3kw hubs. We are talking about 350a and 300a phase.
Also worth mentioning that battery amps is also the factor, not only phase current as you mentioned. Talking about slow speeds and starting from stand still. With fast wound motor you draw more amps from battery because you set more amps on your controller to achieve the same expected performance from stand still.
Ah ok. I think I see where I steered the wrong direction. If we are using the same battery pack/not adjusting the system voltage then the faster winding will require more battery current to achieve similar starting torque.
Commuter/Street Build viewtopic.php?f=6&t=98286:
Rocky Mountain Element
Magic Pie 4 front + Leafmotor 1500 rear w/ Infineon 4 Clone @ 200A phase
Samsung 40T 14S7P

Offroad Build viewtopic.php?f=6&t=102195:
2019 Rocky Mountain Blizzard 20
Cyclone "3kw" 13T motor to 36T chain ring then 32T chain ring to 11T-46T Cassette @ 100A phase
em3ev 14S5P 30Q or 14S6P 25R pack

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Re: Again...3T, 4T, 5T, 6T difference

Post by j bjork » Nov 23 2020 10:18am

pwd wrote:
Nov 23 2020 9:56am


Ah ok. I think I see where I steered the wrong direction. If we are using the same battery pack/not adjusting the system voltage then the faster winding will require more battery current to achieve similar starting torque.
No, for more starting torque you need more phase amps. Not battery amps. The battery A dosent really matter (if you dont go to extremes) in what torque you can get with the different winds, but with lower kv you can get away with a weaker battery. That is because you get less power from the lower kv motor at a given voltage.

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Re: Again...3T, 4T, 5T, 6T difference

Post by pwd » Nov 23 2020 10:40am

j bjork wrote:
Nov 23 2020 10:18am
...if you dont go to extremes...
Can you explain what you mean by "go to extremes"?
Commuter/Street Build viewtopic.php?f=6&t=98286:
Rocky Mountain Element
Magic Pie 4 front + Leafmotor 1500 rear w/ Infineon 4 Clone @ 200A phase
Samsung 40T 14S7P

Offroad Build viewtopic.php?f=6&t=102195:
2019 Rocky Mountain Blizzard 20
Cyclone "3kw" 13T motor to 36T chain ring then 32T chain ring to 11T-46T Cassette @ 100A phase
em3ev 14S5P 30Q or 14S6P 25R pack

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Re: Again...3T, 4T, 5T, 6T difference

Post by j bjork » Nov 23 2020 12:50pm

Well, if you have a battery that can deliver 20A it probably isn't enough to get 400 phase A even from 0 rpm.

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Re: Again...3T, 4T, 5T, 6T difference

Post by Sparfuchs » Nov 23 2020 3:48pm

minde28383 wrote:
Nov 22 2020 7:09pm
probably qs 205 3kw.

Regarding winding. There is no best option. All options are ok and great.
More Turns, more it heats up with the same amps but more torque from starts.
Less Turns more dynamic in higher speed but be prepared to get new battery.

Also dynamic depends on what rim size you get.

If you will get fast winding your will have less dynamic ride than you would have with 5T or 6T.
If you get slow motor 5t or 6t you will get better dynamic with you weak battery.

Unlocked is not necessary if getting 5t or 6t. But some use 200a on 5t but it's insane torque and fast motor heat up, therefore small wheel, ferrofluid, heat sinks prefered.

More turns, more resistance, more torque per amp. You get more torque but need to cool down motor.

If want wheeles than 5t, especially with your battery you will be disappointed with faster motor. If you get better battery than maybe 4t, but if you really require wheelies than 5t (6t if wheel size is very big).
But overall 4t is great, 3.5t is great too; need stronger battery.
with ~20s, field weakening:
5t - 85 kmh
4t,3.5 105kmh

with no field weakening slower by ~15 ~20 km/h.

keep in mind less speed when battery gets discharged or in you case will also sag (drop voltage on high discharge) because only 6 paralel. Smaller wheel also help for wheelies and motor heats less , for ex 17'' rim or even 16''.
I guess/hope i understand it now much better.
So as i got that right:
A slow motor is able to deliver more torque per amp and thats why it does not need such a big battery and can perform "faster" at the beginning compared to a fast motor with same battery and controller setting.
A fast motor need more amps to deliver the same performance than the slow one and thats why a bigger battery is needed. The advantage of a fast one is that it can reach more high speed.
Right so far ?

But i don't really get why a fast one can do more top speed than a slow one. Is it because you would just burn a slower one because of the thinner copper if you push enough amps into it to get the same top speed?
Or are we now at the point were something with voltage gets importent? :D

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Re: Again...3T, 4T, 5T, 6T difference

Post by Sparfuchs » Nov 23 2020 3:53pm

j bjork wrote:
Nov 23 2020 10:18am
pwd wrote:
Nov 23 2020 9:56am


Ah ok. I think I see where I steered the wrong direction. If we are using the same battery pack/not adjusting the system voltage then the faster winding will require more battery current to achieve similar starting torque.
No, for more starting torque you need more phase amps. Not battery amps. The battery A dosent really matter (if you dont go to extremes) in what torque you can get with the different winds, but with lower kv you can get away with a weaker battery. That is because you get less power from the lower kv motor at a given voltage.
Hmmm, but where does the controller get the phase amps from ? I don't really understand how a controller can deliver more amps (phase) than it takes (battery). Is this a conversion made of the voltage ?

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Re: Again...3T, 4T, 5T, 6T difference

Post by Chalo » Nov 23 2020 4:30pm

Sparfuchs wrote:
Nov 23 2020 3:53pm
Hmmm, but where does the controller get the phase amps from ? I don't really understand how a controller can deliver more amps (phase) than it takes (battery). Is this a conversion made of the voltage ?
Yes, you can think of a brushless motor controller as a variable frequency inverter and voltage converter. It's usual for the maximum phase current to be double the battery current.
This is to express my gratitude to Justin of Grin Technologies for his extraordinary measures to save this forum for the benefit of all.

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Re: Again...3T, 4T, 5T, 6T difference

Post by minde28383 » Nov 23 2020 4:50pm

Sparfuchs,
you got all things correct regarding slower and faster wounded motors.
Slower motor has less rpm per volt; fast wound motor has more rpm per volt. Yes, max speed depends on battery voltage (20s 84v). Max battery voltage determines how fast it will spin, therefore 5T will reach ~70kmh and 4T will reach ~90kmh with the same 20s battery.

T stands for turns around teeth, type into google images, will see lots of pics of hub stator teeth. Copper goes around teeth (4T or 5T and any other number of turns around stator teeth 7T, 6T, 3T, mid number 2.5T two and half turn, or 3.5T - three and half turn) and determines how fast motor will spin per volt.

When you increase speed you phase amps goes down till it becomes equal to battery amps.
From stand still you hit throttle to the ground and 350a goes to motor. You pick up speed 10kmh amps decrease to 300a, 20kmh - 250a,30kmh - 200a .... 90kmh - 150a --- amps becomes battery amps (150a). You might not need so many amps to sustain such rapid movement and drag yourself through space with all this resistance and heat as waste product but more amps with more voltage means more dynamic, faster acceleration. We need those amps to reach certain speed as much fast as possible, but after that when cruising, - amps decrease because resistance decreased, except still we fighting with air, wind, tire resistance, or ascending up hill, plus motor itself eats energy to spin itself.
There is bunch of electronic parts inside controller which control how these amps will be released and fed by the motor.
Controller is just a converter, its basic function is quite simple but we need it perform in certain way, plus want good efficacy, high power, additional features, smooth acceleration, regenerative braking and bunch of other stuff like various protections from overheat, from wrong installation ie human error, and at the end it gets complicated. New controller do things better but market is small, production small in quantity, demand is small too compared with internal combustion engines, that is why they are expensive.

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Re: Again...3T, 4T, 5T, 6T difference

Post by Sparfuchs » Nov 23 2020 6:30pm

Chalo wrote:
Nov 23 2020 4:30pm
Sparfuchs wrote:
Nov 23 2020 3:53pm
Hmmm, but where does the controller get the phase amps from ? I don't really understand how a controller can deliver more amps (phase) than it takes (battery). Is this a conversion made of the voltage ?
Yes, you can think of a brushless motor controller as a variable frequency inverter and voltage converter. It's usual for the maximum phase current to be double the battery current.
Thanks a lot chalo, good to know :)
minde28383 wrote:
Nov 23 2020 4:50pm
Sparfuchs,
you got all things correct regarding slower and faster wounded motors.
Slower motor has less rpm per volt; fast wound motor has more rpm per volt. Yes, max speed depends on battery voltage (20s 84v). Max battery voltage determines how fast it will spin, therefore 5T will reach ~70kmh and 4T will reach ~90kmh with the same 20s battery.

T stands for turns around teeth, type into google images, will see lots of pics of hub stator teeth. Copper goes around teeth (4T or 5T and any other number of turns around stator teeth 7T, 6T, 3T, mid number 2.5T two and half turn, or 3.5T - three and half turn) and determines how fast motor will spin per volt.

When you increase speed you phase amps goes down till it becomes equal to battery amps.
From stand still you hit throttle to the ground and 350a goes to motor. You pick up speed 10kmh amps decrease to 300a, 20kmh - 250a,30kmh - 200a .... 90kmh - 150a --- amps becomes battery amps (150a). You might not need so many amps to sustain such rapid movement and drag yourself through space with all this resistance and heat as waste product but more amps with more voltage means more dynamic, faster acceleration. We need those amps to reach certain speed as much fast as possible, but after that when cruising, - amps decrease because resistance decreased, except still we fighting with air, wind, tire resistance, or ascending up hill, plus motor itself eats energy to spin itself.
There is bunch of electronic parts inside controller which control how these amps will be released and fed by the motor.
Controller is just a converter, its basic function is quite simple but we need it perform in certain way, plus want good efficacy, high power, additional features, smooth acceleration, regenerative braking and bunch of other stuff like various protections from overheat, from wrong installation ie human error, and at the end it gets complicated. New controller do things better but market is small, production small in quantity, demand is small too compared with internal combustion engines, that is why they are expensive.
I'm so thankful for all your helful and detailed answers and informations. Thank you so much :)

But how does it get the motor to top speed if the controller levels down the amps fed to the motor ?
And is field weakning involved in some of those processes ?

So what are the disadvantages and adventages of volts and amps ? I mean it seems like some people use high voltage and others prefer many amps. You know what i mean ?

For now i have as mentioned a 20s6p battery with nominal 72V (20×3,6) Would it be a good idea to change for example to a 24s battery with the 5T motor ?

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Re: Again...3T, 4T, 5T, 6T difference

Post by serious_sam » Nov 24 2020 4:51am

minde28383 wrote:
Nov 23 2020 9:09am
Also worth mentioning that battery amps is also the factor, not only phase current as you mentioned. Talking about slow speeds and starting from stand still. With fast wound motor you draw more amps from battery because you set more amps on your controller to achieve the same expected performance from stand still.
No. Power is power. The fast wind motor will not draw more amps from the battery at the same expected performance as the slow wind.

If the fast wind and slow wind accelerate at the same rate ("same expected performance"), then they are accelerating with the same power. So they both use the same power (and therefore amps) from the same battery (plus or minus a negligible difference in conversion efficiency). The battery provides exactly the same current output for both motors.

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Re: Again...3T, 4T, 5T, 6T difference

Post by minde28383 » Nov 24 2020 7:41am

serious_sam,
indeed, power is power, but unfortunately you won't have the same physical ebike performance (movement, dynamic, acceleration) with different T motor versions with the same electrical Power.
The fast wind motor will not draw more amps from the battery at the same expected performance as the slow wind.
Neh, it's not about that, it's about that you will have less acceleration with the same electrical power. Therefore you set more amps on controller for faster wound motor. So some more energy waste in slow speeds, especially starting from stand still. This is what people typically do therefore higher energy consumption. Higher battery amps because faster wound motor have less Nm per amp. That is how controllers are made, you need to increase battery amps too to have more phase amps.
Maybe assuming that slower and faster motors will perform the same with the same power you are not considering one of the main parts in the setup - controller and that its phase amps amps are at certain limit.

Topic owner mentioned that he wanted best dynamic and acceleration (wheelies) and require certain speed rather some power. Therefore it is important to understand that sacrifices are inevitable using different motor versions. You gain something more but lose something else.

Topic is "Again...3T, 4T, 5T, 6T difference".

I'll copy paste one key sentence from my last topic because this is the key to understand why you might will use more energy with fast motor. It is not that you have to use more energy, but more amps (with lower T), because might seek the same initial (as with higher T version) acceleration and set higher amps:
'With fast wound motor you draw more amps from battery because you set more amps on your controller to achieve the same expected performance from stand still.'

Consider typical setups.
One with 5T and another with 4T motor. Is is know that these two motors have different:
amps per Nm and rpm per volt

You get some battery 20s15p. Assume battery is able to supply 150A constantly.
Your controller one of the most widely used is set to 150A battery and 350A phase (some most used controller priced ~200usd).
Compare the same ebikes. Ebikes are the same weight, with the same wheel diameter, and ride on the same surface. All circumstances are equal. All the same but the motors are different, ie 5T and 4T.

Different T perform differently from stand still.
They reach different max speed,
They accelerate differently.
Not that they reach different max speeds but different motors perform differently in different speeds too.

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Re: Again...3T, 4T, 5T, 6T difference

Post by kdog » Nov 24 2020 8:27am

Whoa chalos back! Had to re read to check the date.

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Re: Again...3T, 4T, 5T, 6T difference

Post by minde28383 » Nov 24 2020 8:38am

I'm so thankful for all your helful and detailed answers and informations. Thank you so much :)

But how does it get the motor to top speed if the controller levels down the amps fed to the motor ?
And is field weakning involved in some of those processes ?
motor gains acceleration with volts and amps together. Together they are power.
You control it with throttle. When you start full throttle your ebike you push about all amps your controller is set to from your battery.
Might look into ohm's law. amps * volts = power
Volts determines rotation speed, measured rpm. You got lots of them in your battery 72v.

FW gets involved if you set it to be involved in your controller. There is option to not enable it. With FW you gain more speed but waist energy, create heat. The one you are set to acquire has this feature. It has but it is not best implemented. You will have it but it is crap - lots of wasted energy into heat. This might be or not of the reasons to pay three times more.
So what are the disadvantages and advantages of volts and amps ? I mean it seems like some people use high voltage and others prefer many amps. You know what i mean ?
Yes, I know what you mean. This is correct question. Unfortunately answer is long and looking from different perspectives might look different. Few things to broaden your view.

More voltage means less amps to achieve the same power. We are still about ohm's law.
More amps means less volts to achieve the same power. We are still about ohm's law.
By 72v we are somewhere in reasonable popular limits where we can get controllers and chargers. But these slightly different voltage 60v-120v are used too. But higher voltage controllers are rearer, might cost more.
Why we are not using for example 500 volts? Because high voltage is dangerous and no cheap controller available.
Why we use 72v? Because controllers, chargers are available and reasonable price. Not so dangerous but already dangerous voltage.

For now i have as mentioned a 20s6p battery with nominal 72V (20×3,6) Would it be a good idea to change for example to a 24s battery with the 5T motor ?
yes, it's ok idea. All voltages are ok, you just reach higher speed. Might gain more speed and more power overall. Compared 20s-~70kmh vs 24s ~90kmh. But 24s voltage is too high for the controller you chose. If want more than 20s and use the same controller than can chose up to 22s but for sake of mind maybe better 21s. It's better not to be at very limits of electrical equipment.
you can use 24s with differet T motor version too.

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Sparfuchs   100 W

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Re: Again...3T, 4T, 5T, 6T difference

Post by Sparfuchs » Nov 24 2020 12:11pm

minde28383 wrote:
Nov 24 2020 7:41am
serious_sam,
indeed, power is power, but unfortunately you won't have the same physical ebike performance (movement, dynamic, acceleration) with different T motor versions with the same electrical Power.
The fast wind motor will not draw more amps from the battery at the same expected performance as the slow wind.
Consider typical setups.
One with 5T and another with 4T motor. Is is know that these two motors have different:
amps per Nm and rpm per volt

You get some battery 20s15p. Assume battery is able to supply 150A constantly.
Your controller one of the most widely used is set to 150A battery and 350A phase (some most used controller priced ~200usd).
Compare the same ebikes. Ebikes are the same weight, with the same wheel diameter, and ride on the same surface. All circumstances are equal. All the same but the motors are different, ie 5T and 4T.

Different T perform differently from stand still.
They reach different max speed,
They accelerate differently.
Not that they reach different max speeds but different motors perform differently in different speeds too.
There is a interessting video of two exactly same cyclone e bikes but with differend turns (4T vs 5T) if someone want's to see it :)
https://www.youtube.com/playlist?list=P ... pfrPS3TbXz

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minde28383   10 kW

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Re: Again...3T, 4T, 5T, 6T difference

Post by minde28383 » Nov 24 2020 12:42pm

yes, indeed. Ideally they could pick riders of equally weigh but they still made the point.

j bjork   10 kW

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Re: Again...3T, 4T, 5T, 6T difference

Post by j bjork » Nov 24 2020 12:54pm

They didnt even mention the phase amps..
What point did they make, that a higher turn count will make more torque when it is less limited then the lower turn motor?

There are a lot of threads about this, here is a recent one:
viewtopic.php?f=2&t=109130

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minde28383   10 kW

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Re: Again...3T, 4T, 5T, 6T difference

Post by minde28383 » Nov 24 2020 1:06pm

nevertheless don't get discouraged by faster windings. They are great unless forest and hills is your territory or smaller battery and controller accessible only.
By looking more and more to these bikes it will became clear that it's almost the same what motor T version your use. It's the controller and the battery which determines how it will accelerate. And or course wheels size and ebike&riders weights.
But if you stick to certain voltage and certain controller than you need to choose motor accordingly.
You can get the same performance with higher T winding and higher voltage battery compared to lower voltage battery and lower T motor winding.

The thing is that controllers have amp limits which we would want to be higher when using low winding motors. Also need stronger battery for low T version.

Consider two setups with the same battery capacity. Which one you will discharge sooner.
setup with 3T 200a/500a
setup with 5T 150a/350a
You can make them discharge similarly by riding it slowly, but it is very likely that you will apply full throttle and 3t will drain battery sooner.

Expensive controller can have more power but smoother and controllable acceleration. If you never tried powerful setup you can't be sure that you will want to use that abrupt acceleration, unless you know beforehand.

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minde28383   10 kW

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Re: Again...3T, 4T, 5T, 6T difference

Post by minde28383 » Nov 24 2020 1:18pm

j bjork wrote:
Nov 24 2020 12:54pm
They didnt even mention the phase amps..
What point did they make, that a higher turn count will make more torque when it is less limited then the lower turn motor?

There are a lot of threads about this, here is a recent one:
viewtopic.php?f=2&t=109130
These lad made their point. Most ebikes are sold with higher T because more Nm per Amp and people prefer bigger wheel diameter in general. Also can use cheaper controllers with less amps which people find expensive anyways already and get stronger acceleration from standstill compared with lower T hub version.

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