Bafang motor intermittent loss of power

The most common reasons that power is being cut to the motor are:

1) the speed sensor magnet is not aligned 

2) the brake is being touched

3) the brake sensor is set too sensitive or

4) the bike has inadvertently been set to level 0

In order to diagnose the possible cause of the problem. There are several questions that need to be addressed:

1) Does the problem occur in both throttle only and pedal assist

2) Is the display reading a speed. If there is no speed reading it is likely a magnet issue

**sometimes you can bypass the speed sensor by changing the "auto OFF" setting to NEVER. This will likely work if the bike is automatically turning off every 5 min

3) Is there any chance the brake is being applied by the rider or from branches or other objects on the handlebars.

**to test the brake sensor, you can ONE AT A TIME disconnect the brake lever sensor at the handlebars. The brake sensor is the standard plug similar to the display plug. Disconnect the left one and see if the problem is corrected. Next try the right one. If unplugging either brake sensor solves the issue, then the bike can be ridden with the sensor unplugged until you can reduce the sensitivity by loosening the bolt that attaches the sensor into the brake lever by 1/4 turn

4) Is the battery fully charged

5) Is it extremely cold or was the bike stored outside

6) Are there any error codes. If there is an error code. The code will provide the cause of the problem

7) Has anything been added or changed on the bike?

***BE EXTREMELY CAREFUL PLUGGING THE ELECTRICAL PLUGS BACK. YOU WILL NEED TO ALIGN THE ARROWS AND IF THE PLUG IS DAMAGED YOU WILL NEED TO REPLACE THE ENTIRE WIRING HARNESS.

Based on the information provided, the cause of the problem can hopefully be isolated to the most likely cause. Once the cause has been identified the typical process is the start with easiest remedy and work down the list to the most complicated.