How to Disable the Throttle of an Electric Bike With an Invisible Switch

Hi folks, in this tutorial we will see how to disable the throttle of an electric bike (in my case a cool Fiido D4S) with a mini switch that is almost invisible to sight.

You can read this article also here

Supplies

Slide switches
Bipolar cable similar to that of the ebike itself
Switch plastic case (which can be 3D printed)

Step 1: Make the Electrical Connections

Surely you already know how to connect a switch but you have to pay attention to which wire to interrupt the throttle.

In fact, the accelerator of the fiido d4s is nothing more than a potentiometer and like all potentiometers in digital electronics, they have three pins:

The red one: positive
The green one: signal (voltage from 0Make the electrical connections to 5V)
The black one: negative (obviously the colors can be different)

A digital electronic potentiometer is used to send a voltage from 0 to 5V to the control unit or the microprocessor commonly.

This can be achieved by connecting positive and negative to the potentiometer so that there is a voltage between the two pins.

If you position the potentiometer halfway, the central pin (signal) which is the one that moves inside the potentiometer, will show a voltage of approximately 2.5V between negative and signal.

This is how a microprocessor or the ebike control unit understands in which position the potentiometer is.

That said, the wire we need to break is the positive so that the error doesn't appear on the bike monitor. (the mistake comes out to me anyway but I hope it doesn't happen to you.)

Step 2: Interrupt the Red Throttle Wire

After you understand how the throttle works and how to break the red wire, it's time to take the switch and solder its wires into a cable very similar to those of the bike.

Once this is done, insert the switch cable inside (next to the throttle cable) of the throttle, where its wires are.

After doing this, unscrew the throttle screw, remove the cover and you will have access to the red wire that you will need to cut in half and solder the switch wires to the two halves.

Close everything and test the system!

Step 3: Position the Switch So That It Cannot Be Seen

Once the electrical part is finished, you just have to place the switch in a part that is not visible.

Having used a slide swich which is very thin, I had no problem mounting it behind the monitor of the bike itself and, as you can see from the cover image, it is practically invisible!

Now, to run the cable from one side of the handlebar to the other, don't run it directly or you will see and be aesthetically ugly! Rather do as I did, run the cable along with the throttle cable down to the middle of the cable bundle and then make it into a u-turn and pull the cable up to the other side of the handlebar.