Installing the Motor Controller and Connecting the EV Controls to bring the Bike to Life.
- evconversionrider
- Mar 21
- 4 min read
We are now in the final stages of installing the Motor Controls and connecting the Motor and Switchgear to bring the bike to life. By the end of this part of the build, we will have the motor running.
It is now time to reinstall the switchgear, cable connections, and controller, which we have already test fitted, onto the top of the battery enclosure.
We will begin by positioning the Motor Controller and Main Contactors, then secure the bolts using spring washers and thread locker.
I decided to secure an aluminum strip on each side of the motor controller to hold it in place. With the strips bolted down on both sides, the controller is very secure.
With the controller and contactors now installed, I will start connecting the motor cables to the Controller. I have bought some silicon lug covers and have five sets of red and black terminal covers. I've decided to use the red covers for the positive supply on the contactors and the Motor Controller. The black terminals will be used for the main negative connection to the Controller and, due to a shortage of red covers, also for the motor cables, as they are only live when the motor is in use.
We can now attach the motor cables to the controller and make sure there are no exposed connections by fitting the terminal covers.
Fortunately, when connecting the Motor Cables, the middle cable was somehow longer than the others, allowing them all to fit perfectly.
The negative output cable from the BMS is presently taped up. To ensure safety, the next cable I will connect is the main negative cable from the BMS to the Motor Controller.
The only way I could connect the negative cable was by bolting the lugs together, as there wasn't enough space or cable from the BMS to use a linking bar.
To achieve a solid connection, I needed to file the corner of the 50mm lug so that the 10mm lugs could bolt flat against each other, maximising the surface area for the connection.
After tensioning the bolt, I applied two layers of heavy-duty heat shrink to cover the connection, ensuring the connection is both protected and secure.
Next, I will connect the positive cable from the fuse to contactor number 1, which is referred to as the precharge contactor. Furthermore, we will link the charging cable between the live side of the contactor and the charger fuse.
We will hold off on installing the main fuse until the motor controller is ready to function.
In this video, we have linked the cable from the secondary side of Contactor 1 to the DC-DC Converter through a fuse in order to charge the bike's 12-volt battery.
Subsequently, we linked the Pre-charge resistor to the primary side of Contactor 2 via the link bar between the Contactors, and then connected the last cable from the Secondary contact to the controller input.
We have also connected the control cable from the motor to the controller, as well as the control cable that links to the throttle, screen, and kill switch/inertia switch.
The last wire connected is from the controller's positive terminal to the display screen on the handlebars to monitor the voltage level across the supply to the controller.
I recently acquired some longer screws to secure the lid of the battery enclosure. These screws are a bit longer than necessary, so I will measure each hole to ensure they do not extend beyond the Rivet Nuts inside the box.
As mentioned in the video, I have designed all the connections and control wiring to be plug-in, allowing me to easily disconnect the control wires from the contactors and motor controller. This enables me to remove the entire Battery, Motor, and Motor Controls assembly from the bike frame for any necessary maintenance on the motor or sprocket.
I have installed the plug to connect the contactors to the bike's controls and will now test the contactors' operation.
With the contactor controls now confirmed to be connected in the correct sequence, I can install the final component of the safety systems: the Inertia Switch. This switch will shut down the bike if activated by any impact. I hope it won't trigger when hitting a pothole, but we'll determine that during road testing.
The final wires to connect are for the motor controller, which include the Throttle, Control Screen, and Kill Switch circuit linked to the Inertia Switch. I'll need to take off the front fairing to find the plugs I installed beneath the new dash on the bike.
With the dash plate accessible, I need to cut a slot in the panel to slide the BMS Monitor into a spot on the dash, enabling me to receive battery information while the bike is in use.
With the main fuse in place and the BMS output Discharge feature activated, I am now able to test the Motor Controller's operation and run the Electric Motor for the first time since it was installed in the bike.
In this video, I will provide an overview of the connection and operation of the control systems as we operate the Electric Motor.
In our next blog, we will install and connect the final component of the conversion: the chargers for the Main EV Batteries and the DC-DC Charger for the bike's 12-volt battery.
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