Hello from Malta! Need some assistance please

[cellinu]

Hi you all... I need some help as running out of ideas!

I have a MATE eBike which is a joy to ride. Recently my controller fried and I got one of these Chinese ones which included the display so that I would have less hassle finding the connections. I am quite experienced in electronics and managed to change it and it seems to work under test. I mean, when the throttle is engaged the motor turns. Same thing with the pedaling sensors, if I turn the pedals the motor turns.

The only thing this is wrong is that in actual operation, I can hear the motor engaging when I turn the throttle or pedal but it does not provide any torque at all. In fact I tested it again under test conditions and although if I let go, the wheel does turn, if I hold it with one finger it does not. Everything else is working, brake sensors etc but no torque.

What could this be ? I very much doubt its the motor as the bike is not old. Besides, when I connect the "learning" cables the torque seems to be there. I could obviously only test the "learning" mode on test and not on the road!

Any ideas please ?

 

[indianajo]

Welcome to the site.
If you have only two phases of the three connected, the motor would actually spin, but not have torque. Get an amp clamp type meter, or put a .1 ohm resistor in series between the controller and motor then measure the AC voltage over it. If you have two phases with current and one not, that would explain it.
I recieved two defective batteries, one from Amazon, one from E-bay. It is quite possible somebody sold you rejected product. I in fact received a headlight that would not turn off from the Local Bike Shop. So there are fraudsters everywhere. If you can figure out your controller problem before 30 days are up, you can get your money back. Possibly one pair of FET outputs is bad. Possibly there is a bad solder joint in the controller.
Caution, bad crimps on the those fat wire terminals to the motor can also block the current. That is your responsibility since your motor is old. You can read resistance through the motor terminals to make sure it is the same all three ways.