Battery
chemistry has nothing to do with where the electrons are flowing. What's more important is that your seperate battery supply's positive power can return back to it on the negative side. This is why it was recommended to connect both battery negatives together. To have the light work properly thru the brake switch is half way there. Keep that circuit as it is.
Now to tackle the issue of hooking up to the controller.
Couple things stand out... There is no "ground" at the handlebar brake switch. It's purpose is to provide a connection, or "switch" the incoming 12vdc power to the wire going to the positive side of the brake light. You have a hot side, and a switched side. The switched side becomes hot or positive voltage when the switch is made by actuating the brake lever.
With your type of brake switch wiring, the controller only needs
one pin actuated or connected to your light braking system wiring.
Your controller has 3 types of braking input.
1) Low brake: Grounds the controller's electronic brake signal to ground.
2) Analog brake: Variable DC input voltage.
3) High brake: 12 vdc positive input to one pin.
Each of these require different wiring.
You are using #3 option.
I do not understand about the aluminum foil conections...
I recommended this.
TommyCat said:
Just a reminder... your taking the 12vdc + line (diagrams blue wire) to the controllers High Brake signal input terminal. If I'm going by the correct manual, Pin #1 that is shared with possible motor temperature input.
TommyCat said:
Where did you terminate the blue wire on the controller? (Pin1 Brk2?)
I do not have a Kelly controller, please verify if this is the correct manual.
The manual I'm using... If this is the wrong one, please let me know!
https://kellycontroller.com/wp-content/uploads/kbs/KellyKBS-XUserManual.pdf
I'm concerned that if your wiring
2 wires, and to the wrong locations you could harm your controller.
The way I see it...