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.
#20721
There seems to be a method to double the top speed of the m365 from 20MPH to 40MPH while using a modified stock controller.

I have done some testing on m365 with an ebay 1000w 84v controller and two 42v 10s batteries in series (20s 84v max).
The stock motor seems to handle the voltage and speed fine, but the 1000w controller is 3x OEM size and is hard to fit anywhere.

The 60A phase current produced torque makes the FWD scooter unrideable. The sensitive throttle also causes issues. Also, the BMS will cut power above 20A while accelerating due to no OEM ESC current data.

Gently accelerating with about 18A of current will yield a top speed of ~30MPH. However, the cheap $35 Chinese controller is a trapezoidal wave drive unit that makes the motor very loud (whines) and inefficient. The OEM m365 controller uses FOC sine wave control and is silent. I have also tried a $30 500w sine wave controller that was silent, but can only take 80v max before exploding. The sine wave controller also seems to give higher top speed at ~35mph while drawing 18A phase current on flat ground.

The ideal controller would be compact, FOC, sine wave , and 100v max. This can be accomplished by modifying the OEM controller.

I found a video in Spanish detailing the modification steps. From what I can understand:

1. Flash custom firmware with above 60km/h speed limit, remove KERS, and add above 84v override(unsure if needed).

2. Remove the ESC control board from housing.

3.On the ESC board, cut the Positive PCB trace going from the XT30 connector to the 63v Capacitor positive terminal.
(VERY IMPORTANT. This will isolate the STM32F Controller and 5v DC converters from the 84v battery supply. ESC and BLE boards will blow if not isolated.)

4. Remove the 63v capacitor on the control board.

5. Add a 100v capacitor to replace the 63v capacitor. Connect the negative lead to the negative capacitor pad and connect the positive lead to the positive of the XT30 input. (The positive capacitor pad should be disconnected from the positive XT30 input at this point)

6. Connect two 36v batteries in series using XT30 series connector harness and plug into XT30 input on ESC.

7. Connect the positive of the 1st 42v battery to the positive capacitor pad on ESC board. (This will supply 42v to power the MCU and 5v DC converters isolated from the main 84v battery pack.)

8? Replace the six MOSFETs with 100v 120A IRFB4110 MOSFETs (Maybe not needed. The default MOSFETs are already 100v 110A STP15810.)

9. Profit???

Based on this Spanish guy's poor quality video:
https://www.youtube.com/watch?v=CfD5VDL ... -0&index=2
I used YouTube auto-translate captions to understand the audio.
Maybe a Spanish speaker can understand better and see if I missed or got any steps wrong.

Has anyone else tried this method? I'm ready to test it; just need to get the parts.
#20861
I know going up to 60ish volt on the stock ESC is possible (capacitor is 63v). I'm sure the max voltage you can set with cfw is 63v?

I've wrecked my stock ESC after upgrading the hub motor and didn't take regen braking into account.
Currently got stock battery plus 4s3p in series.

I'm expecting a clone esc to play with today.
Straight off I'm going to switch out the mosfets for IRFB4110.
I'm pretty sure I'll need to beef up the traces on the board as well.
It's the main traces and questionable mosfets that I don't trust on the clones.

I do have another 10s3p battery that's why I'm interested in OPs progress.

I have had my BMS disconnected for well over a year now, created more problems than it solved for me.
#20873
Yes much better to leave it connected to keep the system happy. With this set-up in the video everything makes sense to do it this way. Maybe software does not need to be altered as it will just see the 36v from one battery.

The board receives 36v and the MOSFETs get 72v same amount of current. Because the voltage increase the MOSFETS are pushing a higher wattage. Looking at the spec sheet the original MOSFETS handle 250w and the upgrades do 370w

Also the charger is connected to the batteries in parallel so no need to change charger.

With 2 battery packs in series the system will see the lower voltage of the 2 so the two battery packs would want to be the same.

Hopefully someone can try this soon!
#20953
from what I have seen in the Telegram group, you need to make adjustments to the ESC.
Also there are different HW versions available.
It has something to do with the power supply voltage for the mikrocontroller. But I dont remember, since I didnt care much about that.

Going to 12S easier, becaus you only need the compatible BMS.
I will let you know, as soon as my setup is completed. I aim for 12S8P.
#52599
A Friend had that beast. It was a classic m365 with a lime 2.5 battery in serie with the original battery. The scooter was going crazy fast and the range is so tiny at 55 kph. Very fun experience. My friend tried that on a m365 pro but the mosfet blown up within some hours of ride and the scooter was showing error 28. Not a safe mod.

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