Help! Tech assistance please

[Chrisfinkel]

Hi
We have 2 folding electric bikes approximately 7 years old (Batribike).
One of them has now stopped working.
Technical info:
battery: 36v
Controller: sevenstar BDX36ZWS-XJP21
Drive: rear wheel brushless DC motor.

Fault:- Switch battery on, no lights on handlebar display. 40v going into Controller, 40v going to handlebar display, I would have thought it should be 5v, but don't know.
Any input would be welcome.

 

[vfr400]

When the battery is fully charged, the battery voltage should reach approx 42v. If it only reaches 40v, the battery is faulty.

Both the controller and control/display panel are supplied with battery voltage. They have their own step-down circuits to get the 5v for their CPUs.

The battery voltage goes into the controller, but isn't used to power it directly. Instead, it branches out up to the control panel. The control panel contains an electronic switch that sends it back to the controller (blue wire) to power it.

You can bypass the control panel by bridging the red and blue wires, which normally gives PAS levels and normal throttle operation.

Most likely, your control panel has had water in it or you've pulled a wire off the pcb, but it's also possible that you have a battery problem or short circuit that's causing the battery to shut off. You can only see that if you keep your meter on say the control panel connector while you attempt to switch on. If the voltage collapses, it's a short or battery problem, otherwise it's the control panel.

If the voltage collapses, then you can test your battery on the other bike. If it works, you have a short - normally a blown mosfet in the controller, but could be anywhere.

 

[Chrisfinkel]

Thank you vfr400
I have gone down the path of replacing the controller and display with new ones. I've wired everything up and all seems to work except the motor runs in reverse. How can I change its direction?

 

[vfr400]

Thank you vfr400
I have gone down the path of replacing the controller and display with new ones. I've wired everything up and all seems to work except the motor runs in reverse. How can I change its direction?

I'd need to see all the wiring to be sure.

Some controllers have two wires that reverse direction when connected/disconnected.
Some controllers have a self-learning procedure that reverses direction each time you do it.
Some controllers have auto-recognition and setting. With those, there's nothing you can do.
Without any of the above, you swap yellow and green phase wires and yellow and blue hall wires.