building the BESC - 100V, 400A motor controller [NOT RECOMMENDED]

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Of course I read it but a lot of time passed between reading it and actual assembly. So I managed to forget it :(

Btw I did not see on your page what is the max battery voltage. Is it safe to use 24s? Anything higher?
 
Galp,

one of my BESC G2 controllers appears to be working just fine except the USB connection is not working. I dont know if I fried the USB_DM/USB_DP pins on the STM32F405, or the USBLC6 diode clamp, but for some reason it just wont establish serial communication to my computer.

Do you know if there are any other ways to program the G2? Suppose I have one functional controller, and have all the parameters, could I move those parameters over to the my BESC with the broken serial?

Thanks for any ideas,

owen
 
Hey!

You can hardcode default parameters in firmware by changing appconf_default.h in appconf folder and mcconf_default.h in mcconf folder. If you save motor and app configuration xml from the tool you can just copy the parameters from there.

However I think it would be a lot easier to try fixing the usb first. Do continuity test with a usb cable that is plugged in for all 4 connections (vbus, dp, dm, gnd). I think you just have a bad solder joint on the usb connector. The connector is really weird one because it has too short leads and is a bit tricky to solder. Holding the soldering iron on each pad for about 10s and adding lots of solder is the way I'd go to solder it properly.
 
thanks. Yes I agree hardcoding everything is not going to be ideal. Part of this started with a problem at the cable connector when it got over extended and it looked like some pins broke off from the board. I de-soldered the connector and then soldered in wires from a USB cable directly into the PCB holes for the connector. Continuity on each line seems to be okay but I definitely dont understand why it is behaving the way it is. I have learned since this post that actually the USB hub that hung off of my mac seemed to be part of the problem. Connecting through a different hub helped. So this all may just be a problem associated with this host computer. Very strange because my other board is so reliable.

thanks!
 
galp said:
24S should be okay but I wouldn't go much higher.
Click to expand...

Hey Galp. I'm at 24s and I'm trying to push more amps into my QS205 motor. I am using an ADC throttle, setting motor current max to 200, and battery current max to 120. I am using the SolidGeek/VescUart to read average input current. When I take the bike out on the road, I'm getting up to 44mph, which is exciting because that is breaks a new record for me on an ebike, but it's only using about 30 amps. I cant see to get anything above 30 and I'm working on changing the settings in VESC-tool.

Do you have suggestions for VESC settings, or better yet could you post your conf files?
 
Hey owhite,
I have same problem, I'm using QS3000W 138 70H mid-drive motor,
my parameters are almost like yours.
 
owhite said:
Thanks. I've tried a few things but so far I've only gotten about 40 amps max. I'm still getting 50 mph which is good but would to like to know why I cant achieve more. Hopefully Galp will make an appearance with some suggestions.

Also, I'm beginning to suspect the quality of my batteries so I ordered new ones.
Click to expand...

I don't think that batteries are causing the problem, besc has very low starting torque,on flat road I can reach 50kmh and get 80A, same motor and same pack with my old 3kw chinese controller I have no problem, maybe some parameters on vesc tool are wrong, I'm using last firmware BESC_G2_FW. bin that galp has uploaded.
 
Check your duty cycle. If it's near 95% this means the motor cant spin any faster and that's the reason it is not drawing more current. If not there must be something throttling the current.

  • Check what motor temperature you get
  • Check what mosfet temperature you get
  • Check your battery voltage cutoffs
  • Check the current scaling
 

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galp said:
Check your duty cycle. If it's near 95% this means the motor cant spin any faster and that's the reason it is not drawing more current. If not there must be something throttling the current.

  • Check what motor temperature you get
  • Check what mosfet temperature you get
  • Check your battery voltage cutoffs
  • Check the current scaling
Click to expand...

Hi Galp thank you for reply,

could you share your motor and app configuration files.

the problem is not to spin faster, it is spinning on flat road or with no load, but it has low torque startup,
the motor is not rotating on first move.

motor temperature - ok
mosfet temperature - ok
battery voltage cutoffs - ok no problem with different controller
current scaling - ok

what about

Switching frequency it is 20Khz, does it need to be changed to higher value?
Dead Time Compansation it is 0,1µS
 
erdogank --

I just got a massive increase in performance from setting:
motor current max = 200
battery current max = 200

My bike is 43 kg and I got it up to 72kph and THEN the front wheel started to lift up off the ground. At that point I was paying more attention to staying alive so I'm not sure about the amps, but later on I was pulling 80amps at maybe 75% throttle. I also made minor changes to the throttle curve:

https://i.imgur.com/XgZvnOV.png

which I believe just made it more aggressive, but was probably not the cause of power increase. I think that should help with your slow starts. What are your motor and battery current max settings?
 
owhite said:
erdogank --

I just got a massive increase in performance from setting:
motor current max = 200
battery current max = 200

My bike is 43 kg and I got it up to 72kph and THEN the front wheel started to lift up off the ground. At that point I was paying more attention to staying alive so I'm not sure about the amps, but later on I was pulling 80amps at maybe 75% throttle. I also made minor changes to the throttle curve:

https://i.imgur.com/XgZvnOV.png

which I believe just made it more aggressive, but was probably not the cause of power increase. I think that should help with your slow starts. What are your motor and battery current max settings?
Click to expand...

Hi owhite, motor and battery current max are 193A,ADC Control Type is Current,
my bike is 90kg quad bike and with my old 3kw bldc controller I have no slow start.
What are your Switching Frequency, Dead Tiem Compansation parameters?
My Motor and App configuration are attached.
 

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erdogank said:
owhite said:
erdogank --

I just got a massive increase in performance from setting:
motor current max = 200
battery current max = 200

My bike is 43 kg and I got it up to 72kph and THEN the front wheel started to lift up off the ground. At that point I was paying more attention to staying alive so I'm not sure about the amps, but later on I was pulling 80amps at maybe 75% throttle. I also made minor changes to the throttle curve:

https://i.imgur.com/XgZvnOV.png

which I believe just made it more aggressive, but was probably not the cause of power increase. I think that should help with your slow starts. What are your motor and battery current max settings?
Click to expand...

Hi owhite, motor and battery current max are 193A,ADC Control Type is Current,
my bike is 90kg quad bike and with my old 3kw bldc controller I have no slow start.
What are your Switching Frequency, Dead Tiem Compansation parameters?
My Motor and App configuration are attached.
Click to expand...

I changed ADC Current Control to Duty Cycle and Switching Frequency back to 20Khz now it is ok but FETs are heating very fast,I have to install fans and make better cooling, motor is even not warm, QS3000 V3 is very good motor.
 
switching frequency:
pMYgYSW.png


attachments:
View attachment marin_bike.xml
View attachment marin_bike_app.xml
 
owhite said:
switching frequency:
pMYgYSW.png


attachments:
marin_bike.xml
marin_bike_app.xml
Click to expand...

Thank you owhite,

slow start solved,
my BMS max discharge current is 60A, can handle 80A for short time, two new BMS are comming 120A and 200A with relay, will try them also.

now working on
1.Vesc Tool Android apk not connecting to BT module, did you use this apk?
2.Brake issue, VESC I think is not designed for ebike,I solved it with small circuit using opamp, how did you solve it?
3.Mosfet heating, I want to cool them using water cooling as it is used in PC CPU cooling, what do you think about?
4.Looking for a new differencial since my bike is quad bike with midmotor and want to use regen and reverse move.
 
1.Vesc Tool Android apk not connecting to BT module, did you use this apk?
Click to expand...
there's no bluetooth module on the G2 -- the only connection available for the VESC-tool is the USB port into the board.

2.Brake issue, VESC I think is not designed for ebike,I solved it with small circuit using opamp, how did you solve it?
Click to expand...
I have not used ebrake and I dont have a lot of familiarity with how they work on VESCs. Are you using J13 / throttle 2?

3.Mosfet heating, I want to cool them using water cooling as it is used in PC CPU cooling, what do you think about?
Click to expand...
I dont see why you couldn't use water cooling. I agree with your approach, If I was going to try that the first thing I would try would be a CPU cooling blocks and to mount them on an aluminum plate which is bolted to the MOSFETs.

owen
 
Hi owhite,

Vesc Tools Mobile apk is working I used the link

https://forum.esk8.news/t/nrf51822-flashing-setup-in-windows-using-a-stlink-v2/30601

only work with nrf51822 BT module not working with HM-10 BT module

and using this apk I saw max 55kmh , max mosfet temp 57C, my midmotor QS3000 not heating at all max 35C,
I am using a new differencial which can make regen but I have to disable regen since it is causing big reverse torque, I have to adjust FAULT_CODE_ABS_CURRENT error by increasing Max absolute current to 300A it was 200A.
 
owhite said:
only work with nrf51822 BT module not working with HM-10 BT module
Click to expand...

erdogank -- did you add a nrf51822 module to the BESC G2, or are you using some other VESC that has this module?
Click to expand...

yes I added the nrf51822 BT module to my BESC and now it is very easy to monitor and change all values from mobile apk.
 
Hello people

I was riding with my G2 and heard a pop, the bike stopped and I had to walk the bike home. When I opened up the controller I found some burnt parts, and burn marks.

I'm fairly confident of what happened here -- if you look at some my older posts I used metal screws with small nylon insulators in order to mount the MOSFETs to my aluminum plate. This is really not the best situation because all it takes is a shift of about 1mm for any of those screws and blam, youre probably going to smoke some parts. My work around for this involved two tricks. One was to find some non-conductive bolts. These are called "High-Strength High-Temperature PEEK Pan Head Phillips Screws" and are available at McMaster-Carr. The ratings on these bolts far exceed any temp the MOSFETs will reach. The second trick was to use a very nice product called 3M thermal interface pad. This material is spongy, and has an adhesive on it that stuck very nicely on to the aluminum plate. I also used lock washers on the bolts rather than lock-tite. The thermal pad has a 'vibration reducing' feel to it, which built up my confidence of this thing taking the occasional bounce. But most importantly the non-conductive bolts are never going to short, and the pad is supposed to have reasonably good thermal transfer. I'm sticking with this until I have heat problems that require doing something else. I also did not use thermal grease because the stuff is just annoying but if need to I will throw that in there.

Here is a picture of the arrangement:

Cjfhiyk.png


and other links for plates on the bottom that are then bolted to a larger plate. I have taken this for one ride, I did a 60 amp hill climb for 10 or so seconds, and the whole block stayed below 60degrees C.

I'm getting 55mph sprints on my bike so I'm quite happy with the board.
 
I'll also post this here for visibility.

Version v1.1 is now up on my website. It has that stupid inverter removed and silkscreen fixed. Anyone ordering the PCBs should use the v1.1 gerbers.

http://pavlin.si/besc/besc-g2/
 
Hey Galp,

Some mates and I are making moves to build some of these.
I have a SVMC (sabvoton) 72200 maxed out and a battery array that'l do triple that.

I cant find any numbers on hard outputs that you've seen on G2. There are some partial numbers http://pavlin.si/besc/

. Max pack working pack voltage (taking into account spikes from regen)
. Max pack amps can draw (continuous and peak)
. Max phase amps (continuous and peak)
. Lastly, are the above numbers with the firmware HW lock on? (iv seen 380a from a Sur Ron on the VESC forum)

FYI, we're open to attaching G2 to a waterblock.

Thanks so much for your work in the community!!

PS; what was config of your G2 when u shnapped an axel. was that 9c clone axle?
 
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