KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW)

Electric Motors and Controllers
DarkDD   100 µW

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by DarkDD » Jul 05 2018 7:07am

Finally got the ACS758! Now I can use this to its full extent!

Have a question does regen work on application of brake signal? If not how do I do that?

Also can someone please explain the differences between casainho and stancecokes forks! That would be helpful... Thanks!

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by usertogo » Jul 05 2018 9:06am

Hello folks, congratulations on this probably busiest tread of the whole forum. I have been hoping and just searched the tread if anybody has started to work on implementing an open source PCB for this open source firmware? I didn't find anything here in this tread or the status here: https://opensourceebikefirmware.bitbuck ... .html#h1-3
Has anybody initiated schematic capture for example on KICAD? I also am still confused if this is really STM32 or only 8 bit MCU compatible? Maybe if there is interest we can start a separate forum tread on the development of our own open source PCB? I can do pretty good PCB design work even if I am such a NOOB on MCU programming, that I downloaded the source code from the repository and didn't even find the actual code source file in it! Is it written in C or assembler? Thanks for all your tireless work guys!
Last edited by usertogo on Jul 05 2018 11:45am, edited 1 time in total.

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stancecoke   10 kW

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by stancecoke » Jul 05 2018 11:39am

DarkDD wrote:
Jul 05 2018 7:07am

Have a question does regen work on application of brake signal? If not how do I do that?

Also can someone please explain the differences between casainho and stancecokes forks! That would be helpful... Thanks!
Regen already works with the break lever in both forks
Main differences:
Casainho: Phase current limitation, power reduction at low battery

Stancecoke: linear regen as an option, speed limitation, higher erps as an option.

And several differences in details of the code, that the normal user will not recognize.

regards
stancecoke

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by casainho » Jul 05 2018 4:59pm

usertogo wrote:
Jul 05 2018 9:06am
Hello folks, congratulations on this probably busiest tread of the whole forum. I have been hoping and just searched the tread if anybody has started to work on implementing an open source PCB for this open source firmware? I didn't find anything here in this tread or the status here: https://opensourceebikefirmware.bitbuck ... .html#h1-3
Has anybody initiated schematic capture for example on KICAD? I also am still confused if this is really STM32 or only 8 bit MCU compatible? Maybe if there is interest we can start a separate forum tread on the development of our own open source PCB? I can do pretty good PCB design work even if I am such a NOOB on MCU programming, that I downloaded the source code from the repository and didn't even find the actual code source file in it! Is it written in C or assembler? Thanks for all your tireless work guys!
Are you interested in developing the OpenSource hardware?

It is STM8, 8 bits. See here: https://opensourceebikefirmware.bitbuck ... velopment/

Here my sources: https://github.com/OpenSource-EBike-fir ... s_firmware and it is C code.
Developer of the Flexible OpenSource firmware for EBike motor controllers (TSDZ2 and KT) and LCDs (KT-LCD3 and Bafang 850C color LCD).

If you like my work, please consider making a donation. I am being using the donations to buy needed resources for my developments. My paypal: casainho AT gmail.com.

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by honya96 » Jul 05 2018 6:03pm

lqbweb wrote:
Jul 04 2018 5:30am
So, do you think my assumptions are right? Do you think with this system, I could increase my top speed? Right now it is topping at around 40km/h. But at this point I am only using 400w or so. If at this point I press a switch to connect another battery module to increase the voltage to 72V for instance, I should have another 200W more of reliable power right?

Would there be any problem with the hall sensors? can this controller read so fast the halls?
Your assumptions are totally wrong, forget about all that and just get 48v battery.

Lots of wasted time saved.

If Its still not enough, get bigger and faster motor.

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by honya96 » Jul 05 2018 6:19pm

casainho wrote:
Jul 05 2018 4:59pm
usertogo wrote:
Jul 05 2018 9:06am
Hello folks, congratulations on this probably busiest tread of the whole forum. I have been hoping and just searched the tread if anybody has started to work on implementing an open source PCB for this open source firmware? I didn't find anything here in this tread or the status here: https://opensourceebikefirmware.bitbuck ... .html#h1-3
Has anybody initiated schematic capture for example on KICAD? I also am still confused if this is really STM32 or only 8 bit MCU compatible? Maybe if there is interest we can start a separate forum tread on the development of our own open source PCB? I can do pretty good PCB design work even if I am such a NOOB on MCU programming, that I downloaded the source code from the repository and didn't even find the actual code source file in it! Is it written in C or assembler? Thanks for all your tireless work guys!
Are you interested in developing the OpenSource hardware?

It is STM8, 8 bits. See here: https://opensourceebikefirmware.bitbuck ... velopment/

Here my sources: https://github.com/OpenSource-EBike-fir ... s_firmware and it is C code.
I see potencial only if Its gonna have 2-3 Phase current sensors (STM32, true FOC?), for high power applications.

Why would anybody build a 15A 6fet when you can get it for less then 30$.

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usertogo   10 W

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by usertogo » Jul 06 2018 6:14am

honya96 wrote:
Jul 05 2018 6:19pm
casainho wrote:
Jul 05 2018 4:59pm
Are you interested in developing the OpenSource hardware?

It is STM8, 8 bits. See here: https://opensourceebikefirmware.bitbuck ... velopment/

Here my sources: https://github.com/OpenSource-EBike-fir ... s_firmware and it is C code.
I see potential only if Its gonna have 2-3 Phase current sensors (STM32, true FOC?), for high power applications.

Why would anybody build a 15A 6fet when you can get it for less then 30$.
Well if this could be the purpose and the code could evolve further on the STM32 it is a worthy challenge! I don't know why I thought I had read something about STM32 in the beginning like there already was a supplier building an STM32 version or something? Would the code be able to be compiled for STM32?

On the Hardware side the solution could have +18FET positions for example and users could decide how many they actually place... I also wonder if the STM32 could be on one of these inexpensive 40 pin 'stamps' https://www.aliexpress.com/item/STM32F1 ... 17171.html so less SMD soldering and more flexibility to try different codes... I saw mention of AVS758 current sensors, and there are probably many more options and features that the comercial versions don't support...

I was optimistic somebody would have already taken up the challenge, but with a huge support group like participating here I think now is the time, and open source the way! My KiCAD skills are rusty, but I need the exercise anyway! I imagine a new forum thread is advisable - who is in?

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by casainho » Jul 06 2018 10:04pm

usertogo wrote:
Jul 06 2018 6:14am
but with a huge support group like participating here I think now is the time
Unfortunally, there is only one active developer, Stancecoke. I think that your idea will not happen.
Developer of the Flexible OpenSource firmware for EBike motor controllers (TSDZ2 and KT) and LCDs (KT-LCD3 and Bafang 850C color LCD).

If you like my work, please consider making a donation. I am being using the donations to buy needed resources for my developments. My paypal: casainho AT gmail.com.

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usertogo   10 W

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by usertogo » Jul 06 2018 11:46pm

casainho wrote:
Jul 06 2018 10:04pm
usertogo wrote:
Jul 06 2018 6:14am
but with a huge support group like participating here I think now is the time
Unfortunally, there is only one active developer, Stancecoke. I think that your idea will not happen.
One of my finest virtues is a lot of patience ;)
Would you know how reasonable it is to port the codebase to STM32? Are there any specific unusual features the STM32 version will have to support? Otherwise I studied a lot of controller designs, and I would keep many functions modular (such as using LM2596HVS or XL7005A step downs instead of discreet components). Possibly there are already open source boards such as for Lebowsky (hopefully in KiCAD) that could be simply adapted, layout and routing is a small issue in comparison with the part library capture an packages. I will do some research...
Meanwhile I have a small 350W KT controller on order, so I can familiarize myself with the firmware and the code ideally too, so keep up the good work!

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by apple2 » Jul 07 2018 4:33am

I am new to this but yesterday managed to compile the code with no issues except that I had to comment out the following lines from the makefile-windows:
# @$(ENTF) *.asm
# @$(ENTF) *.rel
# @$(ENTF) *.lk
# @$(ENTF) *.lst
# @$(ENTF) *.rst
# @$(ENTF) *.sym
# @$(ENTF) *.cdb
# @$(ENTF) *.map
# @$(ENTF) *.elf
# @$(ENTF) *.adb

It used to get stuck on the cleaning stage and not progress to compiling. I am not sure why these are in the makefile just after clean.bat which does the same.
Anyways, instructions are good if I managed to do it. Thanks for that.

I also fitted the 72v 18fet sinewave controller to the bike and ran it with the standard firmware to make sure halls and phases are wired right.
Also overvolted it to 24s (100v) with the only modification beeing fitting a dc-dc switching regulator instead of the lm317s. Caps and mosfets beeing rated at 100v seem to be doing just fine after 1 day of riding.

Now before flashing the firmware I have a few questions:
1. Is the firmware compatible with the 72v 3kw 18fet controller? It has the current sensor on one of the phases.
2. How does it perform compared to the stock formware? The notes say something about block commutation not available yet. I can feel the motor currently starting in non-sinewave mode and then switches to noiseless shortly after.
3. Does it show battery voltage on LCD3?
3. Do I need to reflash LCD3 with alternative code?

Thank you for your help. Although not a programmer by trade I have some experince and I am looking forward to understanding the code and possibly helping improve it as much as I can.

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by stancecoke » Jul 07 2018 4:52am

apple2 wrote:
Jul 07 2018 4:33am
I am new to this but yesterday managed to compile the code with no issues
First, welcome to this project! :)
apple2 wrote:
Jul 07 2018 4:33am
Now before flashing the firmware I have a few questions:
1. Is the firmware compatible with the 72v 3kw 18fet controller? It has the current sensor on one of the phases.
It should work, perhaps you will have to adjust the calibration for the battery current

Code: Select all

Battery Current cal a
apple2 wrote:
Jul 07 2018 4:33am
2. How does it perform compared to the stock formware? The notes say something about block commutation not available yet. I can feel the motor currently starting in non-sinewave mode and then switches to noiseless shortly after.
user geofft reported, that the controller gets slightly hotter with our firmware than with the stock firmware. For me the main advantage is the possibility to connect the torque-sensor directly. We start with 6steps commutation also. Not with classical "block" commutation, but with just 6 points of the sinusodial wave
apple2 wrote:
Jul 07 2018 4:33am
3. Does it show battery voltage on LCD3?
not as a digtal value, but as bars.

apple2 wrote:
Jul 07 2018 4:33am
4. Do I need to reflash LCD3 with alternative code?
No.

I hope you will be successful!

regards
stancecoke

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by Valopallo » Jul 07 2018 5:01am

honya96 wrote:
Jul 05 2018 6:03pm
lqbweb wrote:
Jul 04 2018 5:30am
So, do you think my assumptions are right? Do you think with this system, I could increase my top speed? Right now it is topping at around 40km/h. But at this point I am only using 400w or so. If at this point I press a switch to connect another battery module to increase the voltage to 72V for instance, I should have another 200W more of reliable power right?

Would there be any problem with the hall sensors? can this controller read so fast the halls?
Your assumptions are totally wrong, forget about all that and just get 48v battery.

Lots of wasted time saved.

If Its still not enough, get bigger and faster motor.
Hmm... I thought that the motor size or the power rating is irrelevant since the power output is dependent from the max current of the controller times the battery voltage... I have read somewhere that people are driving their "250W" motors up to 1kW and above with no problems at all. So the rating of the motor is just implicating the limits of the controller and nothing else. Please, correct me if I'm wrong here.

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by honya96 » Jul 07 2018 5:11am

apple2 wrote:
Jul 07 2018 4:33am

I also fitted the 72v 18fet sinewave controller to the bike and ran it with the standard firmware to make sure halls and phases are wired right.
Also overvolted it to 24s (100v) with the only modification beeing fitting a dc-dc switching regulator instead of the lm317s. Caps and mosfets beeing rated at 100v seem to be doing just fine after 1 day of riding.
The mosfets Are gonna blow sooner or later. Sooner with this FW. Recommend to run 20s max with 100v mosfets.

Thats just how it is, no need to discuss.

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by honya96 » Jul 07 2018 5:20am

Valopallo wrote:
Jul 07 2018 5:01am
Hmm... I thought that the motor size or the power rating is irrelevant since the power output is dependent from the max current of the controller times the battery voltage... I have read somewhere that people are driving their "250W" motors up to 1kW and above with no problems at all. So the rating of the motor is just implicating the limits of the controller and nothing else. Please, correct me if I'm wrong here.
2.2kg gear motor at 48v 20A Will have like 40% efficiency uphill..

you need more than 40km/h, thats why I recommend bigger.

I Run 14s batt, 1000w Direct motor at 5kw with Stock 18fet kunteng. 70km/h on flat.

Cheapest "High" power setup possible.

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by geofft » Jul 07 2018 5:29am

apple2 wrote: ↑07 Jul 2018, 10:33
2. How does it perform compared to the stock formware? The notes say something about block commutation not available yet. I can feel the motor currently starting in non-sinewave mode and then switches to noiseless shortly after.
If you're using the Master Branch you may find that changing the value of MOTOR_ROTOR_OFFSET_ANGLE (Config.h) can make the initial startup a little smoother. For me an offset of 15 here made a noticeable improvement.
BBS02 V2 48v 750w, 12s lipo.
Q128H (36v 201rpm), KT36/48SVPR, LCD3, 48v 12s lipo.

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by geofft » Jul 07 2018 5:40am

Stancecoke:
For me the main advantage is the possibility to connect the torque-sensor directly.
@stancecoke, I'm about to start installing my torque sensor (sempu T2, 10-24v, gen 2 I think..). Is there any useful information you can point me to regarding controller connections... :wink:
BBS02 V2 48v 750w, 12s lipo.
Q128H (36v 201rpm), KT36/48SVPR, LCD3, 48v 12s lipo.

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by lqbweb » Jul 07 2018 5:43am

honya96 wrote:
Jul 07 2018 5:20am
Valopallo wrote:
Jul 07 2018 5:01am
Hmm... I thought that the motor size or the power rating is irrelevant since the power output is dependent from the max current of the controller times the battery voltage... I have read somewhere that people are driving their "250W" motors up to 1kW and above with no problems at all. So the rating of the motor is just implicating the limits of the controller and nothing else. Please, correct me if I'm wrong here.
2.2kg gear motor at 48v 20A Will have like 40% efficiency uphill..

you need more than 40km/h, thats why I recommend bigger.

I Run 14s batt, 1000w Direct motor at 5kw with Stock 18fet kunteng. 70km/h on flat.

Cheapest "High" power setup possible.
Which motor do you have?

I am just curious why my assumptions are wrong? I know the efficiency would be crap and that I would have to keep an eye on the motor temperature or try to cool it with oil or something. But apart from that?

Have you guys implemented field weakening?

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by Valopallo » Jul 07 2018 6:23am

lqbweb wrote:
Jul 07 2018 5:43am
honya96 wrote:
Jul 07 2018 5:20am
Valopallo wrote:
Jul 07 2018 5:01am
Hmm... I thought that the motor size or the power rating is irrelevant since the power output is dependent from the max current of the controller times the battery voltage... I have read somewhere that people are driving their "250W" motors up to 1kW and above with no problems at all. So the rating of the motor is just implicating the limits of the controller and nothing else. Please, correct me if I'm wrong here.
2.2kg gear motor at 48v 20A Will have like 40% efficiency uphill..

you need more than 40km/h, thats why I recommend bigger.

I Run 14s batt, 1000w Direct motor at 5kw with Stock 18fet kunteng. 70km/h on flat.

Cheapest "High" power setup possible.
Which motor do you have?
Me? I'm just starting my build my bike with this motor; http://www.syimotor.com/productDe_5.html
And I'm planning to buy this https://bmsbattery.com/ebike-kit/721-s1 ... e-kit.html to have 1440W max output from it with my 36V 10ah li-ion battery. Please, if this is not going to work for some reason, let me know. Thnx :)

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by stancecoke » Jul 07 2018 6:26am

geofft wrote:
Jul 07 2018 5:40am
@stancecoke, I'm about to start installing my torque sensor (sempu T2, 10-24v, gen 2 I think..). Is there any useful information you can point me to regarding controller connections... :wink:
You have to get the right voltage from an extra DC/DC converter or from the controller PCB. The rest is quite simple:

Throttle connector: GND and Torque
PAS connector: PAS

the direction signal is not used. Ignore the right hand side of the picture, it shows a controller that is sold in a set with the sensor at aliexpress.

Image

regards
stancecoke

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by honya96 » Jul 07 2018 6:53am

Valopallo wrote:
Jul 07 2018 6:23am
lqbweb wrote:
Jul 07 2018 5:43am
honya96 wrote:
Jul 07 2018 5:20am
Valopallo wrote:
Jul 07 2018 5:01am
Hmm... I thought that the motor size or the power rating is irrelevant since the power output is dependent from the max current of the controller times the battery voltage... I have read somewhere that people are driving their "250W" motors up to 1kW and above with no problems at all. So the rating of the motor is just implicating the limits of the controller and nothing else. Please, correct me if I'm wrong here.
2.2kg gear motor at 48v 20A Will have like 40% efficiency uphill..

you need more than 40km/h, thats why I recommend bigger.

I Run 14s batt, 1000w Direct motor at 5kw with Stock 18fet kunteng. 70km/h on flat.

Cheapest "High" power setup possible.
Which motor do you have?
Me? I'm just starting my build my bike with this motor; http://www.syimotor.com/productDe_5.html
And I'm planning to buy this https://bmsbattery.com/ebike-kit/721-s1 ... e-kit.html to have 1440W max output from it with my 36V 10ah li-ion battery. Please, if this is not going to work for some reason, let me know. Thnx :)
Motor looks good but I wouldn't buy without knowing Its RPM/KV.

It Will be better to get 48v battery

40A Draw for 10Ah Is a bit too much, ok for a while if those Are 10A cells, but really bad range.

Check if your bms can handle 40A, I dont think so.

Field weakening Is not implemented.

I recommend you order 2 controllers if you want to try this FW.

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by 1N4001 » Jul 07 2018 7:03am

stancecoke wrote:
Jul 07 2018 6:26am
You have to get the right voltage from an extra DC/DC converter or from the controller PCB.
I thought the Sempus happily run from 5V despite its datasheet?

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by Valopallo » Jul 07 2018 7:05am

honya96 wrote:
Jul 07 2018 6:53am
Valopallo wrote:
Jul 07 2018 6:23am
lqbweb wrote:
Jul 07 2018 5:43am
honya96 wrote:
Jul 07 2018 5:20am


2.2kg gear motor at 48v 20A Will have like 40% efficiency uphill..

you need more than 40km/h, thats why I recommend bigger.

I Run 14s batt, 1000w Direct motor at 5kw with Stock 18fet kunteng. 70km/h on flat.

Cheapest "High" power setup possible.
Which motor do you have?
Me? I'm just starting my build my bike with this motor; http://www.syimotor.com/productDe_5.html
And I'm planning to buy this https://bmsbattery.com/ebike-kit/721-s1 ... e-kit.html to have 1440W max output from it with my 36V 10ah li-ion battery. Please, if this is not going to work for some reason, let me know. Thnx :)
Motor looks good but I wouldn't buy without knowing Its RPM/KV.

It Will be better to get 48v battery

40A Draw for 10Ah Is a bit too much, ok for a while if those Are 10A cells, but really bad range.

Check if your bms can handle 40A, I dont think so.

Field weakening Is not implemented.

I recommend you order 2 controllers if you want to try this FW.
I guess that's all the information I can get about the motor and I'm using this 36V battery for this first build since I have it already for free. So do you think it would be wiser to save some money for these and buy the s09s maybe? I don't really mind the range that much but would really love to see how much power I can get from this setup as short sprints at least. If the efficiency would come to a beautiful harmony with the battery and the motor, then would the safe bet be some lower current/mosfet controller than the s12s? S09S maybe then?

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by geofft » Jul 07 2018 7:06am

stancecoke wrote:
Jul 07 2018 6:26am
geofft wrote:
Jul 07 2018 5:40am
@stancecoke, I'm about to start installing my torque sensor (sempu T2, 10-24v, gen 2 I think..). Is there any useful information you can point me to regarding controller connections... :wink:
You have to get the right voltage from an extra DC/DC converter or from the controller PCB. The rest is quite simple:

Throttle connector: GND and Torque
PAS connector: PAS

the direction signal is not used. Ignore the right hand side of the picture, it shows a controller that is sold in a set with the sensor at aliexpress.

regards
stancecoke
Thanks, seems straightforward enough. I'm gonna try using the 14v supply from the controller, hopefully the LM317 won't complain too much.. :?
BBS02 V2 48v 750w, 12s lipo.
Q128H (36v 201rpm), KT36/48SVPR, LCD3, 48v 12s lipo.

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Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by honya96 » Jul 07 2018 7:11am

Valopallo wrote:
Jul 07 2018 7:05am
honya96 wrote:
Jul 07 2018 6:53am
Valopallo wrote:
Jul 07 2018 6:23am
lqbweb wrote:
Jul 07 2018 5:43am


Which motor do you have?
Me? I'm just starting my build my bike with this motor; http://www.syimotor.com/productDe_5.html
And I'm planning to buy this https://bmsbattery.com/ebike-kit/721-s1 ... e-kit.html to have 1440W max output from it with my 36V 10ah li-ion battery. Please, if this is not going to work for some reason, let me know. Thnx :)
Motor looks good but I wouldn't buy without knowing Its RPM/KV.

It Will be better to get 48v battery

40A Draw for 10Ah Is a bit too much, ok for a while if those Are 10A cells, but really bad range.

Check if your bms can handle 40A, I dont think so.

Field weakening Is not implemented.

I recommend you order 2 controllers if you want to try this FW.
I guess that's all the information I can get about the motor and I'm using this 36V battery for this first build since I have it already for free. So do you think it would be wiser to save some money for these and buy the s09s maybe? I don't really mind the range that much but would really love to see how much power I can get from this setup as short sprints at least. If the efficiency would come to a beautiful harmony with the battery and the motor, then would the safe bet be some lower current/mosfet controller than the s12s? S09S maybe then?
I think 9 fet Is not tested. You can set lower current with 12fet. Problem with 40A Will be the battery, not motor. That motor can handle much more, if you buy 48v in Future you can get 60A+ from the 12fet with this FW..

But I am still not running it reliably on Direct motor.

We need a developer interested in higher power builds, get Phase current limiting of some kind on the same fork as linear brake, motor temperature power derating, etc etc..

Valopallo   10 mW

10 mW
Posts: 33
Joined: May 29 2018 1:37pm

Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

Post by Valopallo » Jul 07 2018 7:19am

honya96 wrote:
Jul 07 2018 7:11am
Valopallo wrote:
Jul 07 2018 7:05am
honya96 wrote:
Jul 07 2018 6:53am
Valopallo wrote:
Jul 07 2018 6:23am


Me? I'm just starting my build my bike with this motor; http://www.syimotor.com/productDe_5.html
And I'm planning to buy this https://bmsbattery.com/ebike-kit/721-s1 ... e-kit.html to have 1440W max output from it with my 36V 10ah li-ion battery. Please, if this is not going to work for some reason, let me know. Thnx :)
Motor looks good but I wouldn't buy without knowing Its RPM/KV.

It Will be better to get 48v battery

40A Draw for 10Ah Is a bit too much, ok for a while if those Are 10A cells, but really bad range.

Check if your bms can handle 40A, I dont think so.

Field weakening Is not implemented.

I recommend you order 2 controllers if you want to try this FW.
I guess that's all the information I can get about the motor and I'm using this 36V battery for this first build since I have it already for free. So do you think it would be wiser to save some money for these and buy the s09s maybe? I don't really mind the range that much but would really love to see how much power I can get from this setup as short sprints at least. If the efficiency would come to a beautiful harmony with the battery and the motor, then would the safe bet be some lower current/mosfet controller than the s12s? S09S maybe then?
I think 9 fet Is not tested. You can set lower current with 12fet. Problem with 40A Will be the battery, not motor. That motor can handle much more, if you buy 48v in Future you can get 60A+ from the 12fet with this FW..

But I am still not running it reliably on Direct motor.
Please explain, what would be the problem with the battery? I understand that 10ah isn't much range if drawing 40Amps from it but is there something else like heat problems involved when going this high current draw?
Also, what do you mean by; "But I am still not running it reliably on Direct motor" ?

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