An Electric Scooter Community on a Mission to Stamp out Transportation Mediocrity.

Discuss the Xiaomi mijia mi M365 original and pro versions in this forum. Topics include hardware, software, hacking, riding, and everything in between.
#16220
i have a similar problem, only difference being motor doesnt spin freely even after disconnecting the phase wires and the hall sensor
i measured the resistance between the phase wires
blue - yellow 1.6 ohms
blue - brown 1.6 ohms
brown - yellow 0.3 ohms
so i guess the motor is fried ?
#16635
Seriously Avoid using Ca (superglue) to restick magnets on a BL motor.
Ca glues don't tolerate heat and let go. Not a clever use. Use JB weld instead. That said IF the magnets overheat *0C or so enough to loosen factory glues then they are likely demagged. Neo mags don't tolerate heat well.

Other issue: IS this controller burn out endemic with Pro versions only??
Same controller ? was was fitted to the Previous model 365.
Can unplugging the Regen switch from the Brake lever prevent this?
#18226
Hi everyone, i have the same problem. I regularly take steep hills up and down in my city and after 50 km, my M365 Pro started losing power following some vibration and noise, the motor died in few km. When I opened the battery cover, there was no sign of any problem, I disconnected all of the wires circled in the photo. Even after disconnecting, there is still resistance in the front wheel and it does not spin freely. Another issue is the wire with the red circle. Its plastic cover melted a little however there is no sign of burning on the board.

So, my questions are:
- Do you think my problem is related to the board or the motor? I got my scooter from another country so my warranty is not valid in the country therefore I need to order the part accordingly.
- What is the red circled wire is needed for? And is there a way to disable the KERS by unplugging a wire?

Thank you in advance for your support

Image
https://ibb.co/6Xytdc9
#18914
I too have the same problem. Died when driving up a hill. I'm assuming the drive board is dead. I haven't checked yet but will tomorrow. Also, if this is the regen kicking up too much voltage it should not be a problem when driving up hill, right. It should instead be a matter of overloaded drive MOSFETS and over loaded tracks. I can see the region failure mechanism for when driving down hill though. My question is : how to disengage the regen? is it a matter of snipping a wire? I can't imagine the regen does much to extend range. A scooter + my butt doesn't have the weight of a Tesla.

Or, better yet, has anyone come up with a replacement PCB that's better than the stock version? ie,. Able to support 60amps, with beefed up tracks etc. as I see these mosfets are for 30amps max?
Cheers!
P
#19478
Is the M365 controller the same as the M365 Pro controller?! thought it would be beefier to handle the extra power that the battery can provide. I also thought that there would be a temperature sensor on the motor itself to avoid it burning down, specially uphill, saw some video os a guy on youtube that had a blinking sound coming from the scooter that felt like overheated drive.

Thought on buying one myself soon and tinkering with the firmware a bit but seems like you guys fried the controller stock uphill? makes me a little concern about it, since I would also not have local warranty.

I've been doing some extensive research cuz it's not cheap to buy it in a development country like mine, so I came across some stuff that I'd like to share to see if it's a workaround.

I thought at first that the BMS would impose a limitation for the scooter capabilities, but following this thread I believe the controller itself is the problem.
According to the cf page, the standard values for "Sport max phase current" and "Sport max battery current" are 55A and 25A respectively. By doing simple math, by default the max wattage the battery would pass to the motor is 1050w (42v x 25A), I thought on rising it up to 30A (considering 8A per cell in the battery (32A of discharge by 4x10s cells) but lowering the Max voltage from 43v to 41.5v to increase the battery life spam, pushing it to peak 1245w at 41.5v and 1080w at 36V. I've seen people on some other forums and on facebook groups changing the mosfets for better ones and bulking up the battery trail to avoid these issues. Now I'm inclined to do the same just stray out of the box in case I actually buy it.

And about the downhill problem. what would the "max phase current" relate to? the 55A at 42v would result in something like 2310w, would this relate to the KERS + actively forcing energy to the motor to make it slower on downhill? cuz the math says it has nothing to do with the acceleration, wouldn't lowering it down avoid the burning controllers caused by KERS overload?
#19510
Did some more research, max phase has little to nothing to do with the KERS, it's about PWM signal, the high current flows for a very short time; over the peak of the senoidal curve, leaving the BMS current within the specs. It may impact more the capacitors than the BMS, so I was wrong. no luck there.

Apparently the M365 Pro as a more range scooter than the regular M365 is great. To use it's power to go long uphills without a hardware mod may be unwise, the peak power is way out of spec, closing to 1000w, not the 600w on the spec sheet, that's why it's significantly better than Es4 over Hill and on accelerations. But to sustain this peak power for a longer period of time seems to be harmful to the controller, and it's quite too dumb to cut the power before it melts itself down. Better mosfets, piece of coper over the solder path and repasre the controller to the chassis seems to the way to a safer and healthier controller. Won't solve the burnt motor tho. Heard someone talking about putting some kind of fluid inside the motor to cool it down, but can't find exactly what it was.
#19979
Mattr567 wrote:
Sat Aug 17, 2019 12:42 am
tronixcity wrote:
Tue Jul 30, 2019 9:17 am
HAd a customer just now.. his m365 pro motor is dead. mainboard is still turns on and all.. since I I do not have motor available for pro. he just replaced it with normal m365 motor.

longer range :-)


cheers
The mainboard will still turn on when it fries, shows mileage, etc. When you press the throttle though the scooter auto shuts off. I had the same experience, but I had a short in my motor wiring as I wasn't braking nor going downhill when mine let go (also really modded).

Image

When this condition occurs, its basically never the motor ever.
Sc00tr wrote:
Tue Aug 13, 2019 3:12 pm
I’m not seeing a picture of you intended to include one, but if your soldering skills are good and depending on the part that’s burned out then yes you can in theory replace it without replacing the whole controller.
I tried this when mine died, I'm pretty good at soldering and I verified my connections were solid and not touching where it shouldn't. Mine was cooked enough where I added little jumper wires as you can see. It changed nothing and I had to replace the controller. Clearly when this happens it burns another component on the board up. At that point not worth fixing.

Image

The thick solder is me trying to reinforce everything lol. A bit ugly but 100% functional.
In my case, one of the transistors were broken. The wheel were probably hard to turn because the transistor let power through all of the time, and the part of the motor that were connected to that transistor acted as a brake.

(I don't know exactly how brushless DC-motors work, but after some quick Googleing this made sense)
#19993
peteh007 wrote:
Fri Jan 10, 2020 12:55 pm
I too have the same problem. Died when driving up a hill. I'm assuming the drive board is dead. I haven't checked yet but will tomorrow. Also, if this is the regen kicking up too much voltage it should not be a problem when driving up hill, right. It should instead be a matter of overloaded drive MOSFETS and over loaded tracks. I can see the region failure mechanism for when driving down hill though. My question is : how to disengage the regen? is it a matter of snipping a wire? I can't imagine the regen does much to extend range. A scooter + my butt doesn't have the weight of a Tesla.

Or, better yet, has anyone come up with a replacement PCB that's better than the stock version? ie,. Able to support 60amps, with beefed up tracks etc. as I see these mosfets are for 30amps max?
Cheers!
P
Do you have a datasheet for the mosfets? That would be very helpful. I'm trying to find som more powerful mosfets, but I need to know what I'm looking for, like what pin is the collector etc. My controller has two different kinds of mosfets. I guess thats normal. I'll add a picture of the mosfets.

Image

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