I am curious, how do ebrakes actually work?

chyaboi

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So you have your typical ebrakes that shut off the motor when you press the brake. I want to understand better how they work. What is each wires function? Do they carry electrical current? Is the black wire actually a ground, or is it just a power relay wire that carries current and when you press the brake it goes down the "positive" wire to tell the controller to shut the motor off? I have no clue, I am curious! I want to better understand because I am trying to hook up brake lights in with the ebrakes.

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Good question. I believe the brake lever closes a circuit when pulled, and this tells the motor to shut off. Unfortunately there wont be enough current in that circuit to power a brake light, so you'll have to create your own circuit with it's own power source.

This guy has added in a relay to create a brake switch. If you understand simple circuits, you should be able to build something similar.


The relay will need to close 2 circuits whenever the brake lever is pulled:
1. The original brake circuit (to cut power to the motor).
2. The new brake light circuit (to turn on the brake light).

Depending on your ebike, you may get lucky and find that someone has already created a kit which simply plugs in. For example you can purchase Bafang brake light kits here:

 
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Good question. I believe the brake lever closes a circuit when pulled, and this tells the motor to shut off. Unfortunately there wont be enough current in that circuit to power a brake light, so you'll have to create your own circuit with it's own power source.

This guy has added in a relay to create a brake switch. If you understand simple circuits, you should be able to build something similar.


The relay will need to close 2 circuits whenever the brake lever is pulled:
1. The original brake circuit (to cut power to the motor).
2. The new brake light circuit (to turn on the brake light).

Depending on your ebike, you may get lucky and find that someone has already created a kit which simply plugs in. For example you can purchase Bafang brake light kits here:

The problem with those kits is the headlight and taillight are utterly useless. Too small and not enough light power. I've had them before. I did though purchase the wiring kit on it's own and will try to use it to hook up my own lights and switch using the wiring kit. Should work.

It did work, got my OWN turn signals and headlight/rear light with brake light working great.
 
Links to eBay may include affiliate code. If you click on an eBay link and make a purchase, this forum may earn a small commission.
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