reviving a retired pay to ride scooter • finding compatible BLDC controllers

[dosensuppe]

Greetings. I aquired a retired scooter quite a while ago and finally decided that I should give it a more useful purpose than catching dust in the basement.

The ESC looks like any generic e-bike controller, but I can't find any information on it. The model number is: JFKSF-M5
I suppose hijacking the bus system to activate it would be too much of a hassle, so getting a new controller is propably the most sensible approach?

The thick plug as seen on the pics is the motor connector. In addition to the 3 thick phase pins it has 8 tiny pins. What could they be? I suppose that there is no standardization whatsover with the pinouts so I would have to cut the connectors off and rewire for a new controller.
Any recommendations on cheap, compatible BLDC controllers (or on ways to make use of the OEM one) would be appreciated. Thank you.

[dosensuppe]

This connector would plug into the embedded computer, tracking and activating the scooter via the app

[uer166]

Scope the voltages: it's likely at the minimum some hall effect sensors (+5V/GND + 3 hall outputs), and thermistor(s) for temp sensing.

You can move the wheel by hand and see if 3 of the pins are wiggling in sync: from there you can determine what is hall output phase U/V/W or whatever. The temp sensing is likely analog.

[dosensuppe]

Yup, I'll figure it out 
Looking at different ali and amazon listings right now, trying to figure out what controller to choose.
The oem controller label specifies a max current of 22A. Does that mean the motor can take approx. 800w?
Most controllers I found are only specced at 500w and I would of course like to drive the motor at full power.
https://aliexpress.com/item/1005012662787060.html

[voltsandjolts]

The ESC looks like any generic e-bike controller, but I can't find any information on it. The model number is: JFKSF-M5

Maybe you misread a 2 as a 5, because I see JFKSF-M02 exists?

Edit:
Ah, no you are right -M5, I hadn't noticed your picture of the controller.
Sorry for the noise.

There is likely some re-branding of these controllers, so maybe the info here could help you;
https://forums.electricbikereview.com/threads/hacking-ev-bldc-motor-controler-protocol.45043/
https://endless-sphere.com/sphere/threads/kt-motor-controllers-flexible-opensource-firmware-for-bmsbattery-s-kunteng-kt-motor-controllers-0-25kw-up-to-5kw.87870/

[dosensuppe]

This FOSS firmware for those KT controllers looks interesting. but there is the risk I will buy such a controller and it ends up being incompatible, using a completely different MCU. On the surface they all look the same, but who knows how many revisions they churn out in a matter of weeks. The github repo I found doesn't seem maintained anymore.
https://github.com/stancecoke/BMSBattery_S_controllers_firmware
Pic related is the controller I've been eying. Some of the connectors like "self study" and P.A.S seem a bit puzzling to me. https://aliexpress.com/item/1005012662787060.html
Something with a recuperation feature would be quite nice. I have an old DIY e-bike with a cheap controller that barely gets 40km range with a 500kwh battery. And the pad breaks wear down rapidly on that thing, especially if I'm driving through busy cities, having to break at every traffic light

[dosensuppe]

Also I would need a way to limit the speed. In germany you must not legally exceed 20km/h on those scooters.

[darkspr1te]

Lookup e-bike uart 2 protocol, looking at your connector it seems a lot of units out there use it. I also found a unit called M5 bldc controller which uses a different connector for the display (aka MCU) but uses same protocol.


As these unit were designed with hire in mind there is a common protocol , Named Uart 1 and Uart 2 , the can bus versions are just uart over can.
With this common protocol there is a lock/unlock function that you implement in your "display" and it just sends a code to the bldc controler.
Am sure with a arduino and a multimeter you could build a fake display to unlock the device,
https://github.com/jostsalathe/focan-uart
https://github.com/jenkie/Arduino-Pedelec-Controller/blob/master/Arduino_Pedelec_Controller/display_bafang.cpp
https://github.com/Biky-Bafang/firmware/blob/main/protocol.md
https://penoff.me/2016/01/13/e-bike-conversion-software/
https://github.com/EBiCS/EBiCS_Firmware/blob/master/Src/display_No_2.c

[dosensuppe]

apppreciate your efforts
I forgot to mention. The controller also came with a small li-ion battery that would power it when the main battery was removed.
That main battery has a smart BMS that gets activated by the controller. So I guess the secondary battery needs to be plugged in for the thing to do anything.
I tried powering the controller straight up with a bench supply before. propably already fried the original controller since I poked around, randomly connecting one of the bus wires to the VCC line. luckily I have a second one.

So the bus traffic is unencrypted? I guess it's worth a try, hooking up an arduino. Will try that when I get back.
https://github.com/jostsalathe/focan-uart/blob/main/protocolAnalysis/README.md
Maybe I should get one of these 10€ usb logic analyzers.