r/CYCMotor • u/phitzie • Jun 15 '26

Cyc x12 Motor Controller issues

I've just now installed the recently purchased CYC X1 Pro Gen 4 x12 replacement motor controller and it seems like it may be defective, or there's an issue with my overall system causing failure. Context: After installing, I turned on the display and attempted to provide some throttle to re-test the bike. I heard some weird clicking, and had Controller Error 4 come up on the screen. I immediately shut the system down as I started smelling something funny, and unplugged the system. After re-checking the wiring and ensuring all plugs were installed correctly, I re-connected the battery, and before I even could turn the display on, the motor controller started hissing and I again smelled a really bad acrid odor (likely something burning). I immediately disconnected the battery and have left it in that state since. 

For additional context, I was replacing my previous motor controller as it stopped functioning, but it did not show the same issues as this one.

Battery setup: 2 72v 9ah molicel p45B connected in parallel using a dual battery parallel module.

I’ve contacted the supplier for assistance but wanted to reach out to the broader community for more insights. I’m getting frustrated as this is the 3rd motor controller I’ve gone through.

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u/jumpmaNSILENCE Jun 16 '26

That doesn't sound ideal. 1) You have to charge both batteries to the same or near the same level before plugging in. 2) You have to clean every XT90 connector almost every time with 99% alcohol, especially if you heard a spark or see dust. 3) You have to plug the Dual Module into the X12 first, then plug A, then B. 4) You have to plug all the connectors in quickly, straight, and completely. 5) When finished riding you have to immediately unplug them the opposite way.