Phoebe 36V/48V Controller with learning wire

I recently bought this controller off aliexpress. I was attracted by the price, $45 USD, and that the different models supported 36V and 48V with an LCD. I bought their 48V 350W model. Shipped to the USA in about 10 days,

https://www.aliexpress.com/item/24v36v48V350W-BLDC-motor-speed-controller-and-LCD-meter-sets-MTB-Electric-Bike-Scooter-conversion-sets-display/32298642747.html?spm=2114.13010208.99999999.264.4tGqJi

It's fairly small, 3 x 5 x 9 cm, and I'll be using it with a Q100H motor. It comes with the usual 3 phase and 5 hall wires, which I replaced with a 9 pin plug. It is much easier to splice it inside the controller, and there's less concern about solder joints breaking.

I was disappointed that it didn't work at 36 V. I could use the LCD to lower the cutoff voltage from 40V to 32V, so that the LCD power icon worked, but there must be a hard circuit cutoff. But since they sell this for both voltages, I hoped there would be a jumper on the board.

Sure enough, they put it in plain sight and even labelled it 36V.

I soldered in a jumper, and now the controller worked at both 36 or 48 volts. Attaching the wire is pretty easy, if your eyes are good enough to see the connections. At my age, I had a tough time.

Now for a question. This is a learning controller. It has a learning connector. If the circuit is closed when powering up, the controller figures out the phases and spins the motor continuously. Upon breaking the circuit, the motor stops and now the controller can be used. Will the controller ever forget the learning? I'd like to cut off the learning wires to get rid of clutter.

By the way, instructions were non-existent. You have to look at the pictures on the web page, and read the copy. I had to guess as to which plug was throttle and which was PAS.

You can cut the wires just outside the controller, then pull them through to the inside and insulate them in case you ever want to use it on a different bike.

The jumper changes the LVC to 31v, so is too low for 48v. If you want to run both, put a switch on it.

You know you have to connect the white wire to the speed sensor wire in the Q100. New Q100s have the speed sensor wire in the 9-pin connector, but some some of the extension cables from the 9-pin to the three bullet and 6-way block don't have it.

Thanks for the reply! I knew white was reserved for speed sensor in the 9 wire cables, but I didn't know the Q100 H used it. It was on my cables by default and so it got connected. Really like the 9 pin connectors. More controllers should use them.

I'll pull the cruise and learning wires inside.

A switch is a good idea, but I could just as easily leave it at 36V or knock it there by accident. I'll discipline myself to reset the LVC in the LCD display when I switch voltage and get a visual when the battery is low. Shouldn't the LVC in the battery BMS trigger as a last resort? All my batteries have a BMS.

Battery LVCs are normally set lower than the controller - something like 29v vs 31v. I wouldn't trust them anyway. I've done quite a bit of battery testing and find that the LCVs in the BMSs often don't work at all.

I'm not convinced that the LVC you can set in the LCD is actually that. It might be just to set the scale for the battery level display. You need to test it if you're going to rely on it.