Originally Posted by davek181
I built a capacitor pack for my XL out of off the shelf capacitors ar radio shack. I bought three 2700 mf capacitors. (the biggest ones they had) Soldered them together in parallel on a circuit board I bought there too.
Put it in my XL, changed all my instrument lights and taillight to LED. When I kill the engine the neutral light will stay on for about 15 seconds on reserved power. Turn signals, horn and lights all work great when running. Heated grips too.
So far, I think I've figured out that 4500uF and 20 volts is about the minimum. I have seen people (on the web) using 150,000uF and up to 40 volts. I dunno what the top voltage could actually be, but the uF determines amount of power stored, or practically speaking, the length of the charge - how long the lights will stay on... Steve mentioned possibly having one for me, but I'll have your plan as a backup... maybe rob some capacitors from some old electronics or something... I could try some higher voltage ones from a computer power supply maybe, just to see if the capacitor 'cares' what the higher voltage is. The higher uF also takes longer for a charge to be built up but that shouldn't be anything to consider in this application, especially as the ignition circuit is separate from lights on these bikes.