Hi everyone,
I'm troubleshooting a 5-year-old Bafang BBS02 750W mid-drive and I’ve reached a dead end. I am getting an "Unexpected Power On" message immediately upon connecting the battery, followed by a persistent Error 30 (Comms Error) after 45 seconds.
When Error 30 hits, the display hangs on the splash screen and the power button will not shut the system down.
The Hardware:
Motor: Bafang BBS02 (750W), ~5 years old.
Controllers tested: 1 Stock FW, 1 Custom FW (both exhibit the same behavior).
Parts swapped/tested: 2 Batteries, 2 Displays, 2 Main Wiring Looms.
The Diagnostic Clue:
The "Unexpected Power On" message only disappears when I remove the stator. (guessing that there was a short as i reconnected the stator out of the motor to the controller and that error disappeared
However, even with the stator removed, the Error 30 still appears on the display after the 45-second heartbeat timeout.
My Theory / Questions:
Since I’ve swapped controllers, displays, looms, and batteries, the only constant is the motor core/stator.
Is it possible for a faulty Hall sensor or the internal thermal sensor to short the 5V rail so badly that it prevents the controller from communicating with the display?
Has anyone experienced a BBS02 stator failure that "back-feeds" or triggers an "Unexpected Power On" signal?
I’m leaning towards replacing the stator/core, but I’d love to know if there's a specific test I can do with a multimeter on the Hall connector to confirm this before spending the money.
Thanks in advance!
I'm troubleshooting a 5-year-old Bafang BBS02 750W mid-drive and I’ve reached a dead end. I am getting an "Unexpected Power On" message immediately upon connecting the battery, followed by a persistent Error 30 (Comms Error) after 45 seconds.
When Error 30 hits, the display hangs on the splash screen and the power button will not shut the system down.
The Hardware:
Motor: Bafang BBS02 (750W), ~5 years old.
Controllers tested: 1 Stock FW, 1 Custom FW (both exhibit the same behavior).
Parts swapped/tested: 2 Batteries, 2 Displays, 2 Main Wiring Looms.
The Diagnostic Clue:
The "Unexpected Power On" message only disappears when I remove the stator. (guessing that there was a short as i reconnected the stator out of the motor to the controller and that error disappeared
However, even with the stator removed, the Error 30 still appears on the display after the 45-second heartbeat timeout.
My Theory / Questions:
Since I’ve swapped controllers, displays, looms, and batteries, the only constant is the motor core/stator.
Is it possible for a faulty Hall sensor or the internal thermal sensor to short the 5V rail so badly that it prevents the controller from communicating with the display?
Has anyone experienced a BBS02 stator failure that "back-feeds" or triggers an "Unexpected Power On" signal?
I’m leaning towards replacing the stator/core, but I’d love to know if there's a specific test I can do with a multimeter on the Hall connector to confirm this before spending the money.
Thanks in advance!
