Lights on S12S Controller with S-LCD3 Display

[jhendrickson]

I am using an "S12S 500W Torque Simulation Sine Wave Controller" from BMSBattery and an "S-LCD3 LCD Meter for S-Series Controlers" on my bike. The LCD meter has a backlight function that also appears to control headlights and taillights, but I don't see any output on the S12S controller for plugging in a headlight and taillight. Am I out of luck here for using that feature on the display? What are some other solutions for running a headlight and taillight using the 48V battery pack with a single switch for control?

Thanks!

 

[Avitt]

I've got the same controller/display combination, and there is no light output on the S12S. My solution was to make a relay box, which triggers off of the voltage from my unused thottle input.

This little box contains a switch (if needed to turn the lights off, while the bike is on), a 900mA self-resetting polyfuse, a solid state relay, and a DC/DC step-down converter.

It you have an unused controller function (brake, PAS, or throttle), you can use the spare +5V signal as an input to something like this, to automatically control your lights.

 

[d8veh]

A relay takes a relatively high current from the 5v regulator. I wouldn't recommend that for everybody. It would be better to use a transistor to do the switching like they have in the controllers with the connector for lights. You can then safely use the 5v rail to power the transistor. Basically, replace the relay with a transistor.

At battery voltage, lights don't take much current, so a simple handlebar switch is enough.

http://www.banggood.com/78-Handlebar-Motorcycle-Scooter-ATV-Headlight-ON-OFF-Kill-Switch-p-954623.html

http://www.banggood.com/Motorcycle-Bicycle-Assist-Lamp-LED-Headlights-Modification-Spotlight-p-919876.html

 

[Avitt]

Yeah, that's an important distinction, d8veh. A mechanical relay can draw too much current from the controller regulator.

What I'm using is a Solid State Relay, which triggers at a very low 7.5mA. It should provide a safe option for most cases.

Here's a description of the advantages of SSRs:

http://www.scienceprog.com/considering-solid-state-relays-ssr-for-your-projects/

This box is really to provide some automation to the lights. Specifically, I wanted to make sure that my tail light comes on whenever the bike is on (so I would never forget). if you don't want or need automation, then a handlebar switch would work perfectly (and would meet the OP's requirement).