Integrated brake light

[AZOldTech]

So can you just split that wire with something like this?
https://www.amazon.com/gp/product/B07BGRDMTT/ref=ox_sc_saved_title_1?smid=A3FBGZ8EKA6TSC&psc=1

Correct. But the problem is not just the signals but how to use the signals to power a two tone drive/brake tail light. Some controllers have a build in relay that gets engaged when you hit the brakes. So in other words the tail light is powered by your battery the same as your headlight (could be hooked up to be on the same connector and in parallel) and so both the headlight and drive tail light come on when you turn on the light switch (via the LCD display remote). But when you hit the brakes the controller either with its own relay or a relay you hooked up (if your controller doesn't have one) feeds the DC power to the section of your tail light that turns on the brake lights, and so you get a much brighter tail light than just the drive tail light. And in this hook up the brake tail light also works even when the head light and drive tail light is off (just the same as in your car) and you get just the brake lights to come on when you hit the brakes. And that is all fine and dandy as long as you have a tail light that works with the voltages of your ebike (36V-52V). But if not, you are also going to need a DC to DC converter to bring your voltage down to something that your tail light can manage (usually 5V or 12V).

The point of all this is that these higo connectors don't do much to power your tail light unless you precisely know the capabilities of your controller (some controllers have separate headlight and tail light connectors that provide the ebike battery DC power voltage when you turn on the light switch via the LCD display remote). Some others have also a brake light connector that again provide the ebike battery DC power voltage when you hit the brakes. And if your controller doesn't have this, you will have to rig your own circuit to do the same thing from the higo connector brake signals. And in addition you may or may not need a DC to DC converter to bring down the voltage to something your tail light works with if your tail light needs 5V or 12V or works with variable 36-60V. And somehow after you are done you will have to stuff all that bundle of wires and power circuit somewhere for a clean installation.

 

[sl_duck]

I just bought a rechargeable "Xlite 100" tail light, which has an internal accelerometer and goes bright when you slow down. Battery lasts about two weeks of daily commuting. Turns itself on when I start moving, and off when I park. The only thing I don't like about it is it senses ambient light and turns off during the day (the braking function still works) and I'd prefer it to blink during the day as well. Of course I'd have to recharge it more often then. $20.

 

[KLee]

I just bought a rechargeable "Xlite 100" tail light, which has an internal accelerometer and goes bright when you slow down. Battery lasts about two weeks of daily commuting. Turns itself on when I start moving, and off when I park. The only thing I don't like about it is it senses ambient light and turns off during the day (the braking function still works) and I'd prefer it to blink during the day as well. Of course I'd have to recharge it more often then. $20.

I fiddled with the idea of rigging an integrated brake light but like @AZOldTech commented, it can be very complex to do it right. I gave up and bought a Roxim tail light and wired it to turn on with my headlights full time.