FIXED!! Yes after doing much diligent work with a digital micrometer and studying the possible solutions and now reading your experience I believe my solution is what is needed. The controller voltage is unknown and I suspect very sensitive to any resistance from corrosion on the terminals even if it seems microscopic..the wafer block might help The terminals fit better for a while and folks have tightened the key lock for a tighter fit but in the end the problem returns. We know the motor uses lots of power but the controller may be very very sensitive to any Unwanted resistance on the terminals. With that theory I bought a can of electronic contact cleaner and did nothing else like tightening the key or lock - nothing. I used CRC 5103 contact cleaner on the battery terminals and the bike terminals. The problem has been completely resolved on my bike and I had the same complaint as you. Without a wiring diagram for the controller (I’m an engineer) I strongly Suspect the controller to be of very small voltage and the electronics inside of it uber sensitive to any power supply issue that might cause a resistance increase - even micro levels of corrosion on the terminals. These things tend to be designed by electronic geeks that don’t ride mountain bikes and have no idea the environment these terminals may endure. My bike was new and while it was a bit dirty the battery terminals looked perfectly clean visually. However, Two sprays of CRC on those terminals cured my bike of all the problems I reported earlier. The only change I did was that spray cleaner. My bike was fixed with $5 can of CRC. Good luck!!
that is very good info but. how can I see if those terminals are ok or not...I mean, how do you realize about that micro corrosion?? Do you think could be helpful to use sandpaper to clean the terminals??